Problem on a highway - unexplained overheat

Problem on a highway - unexplained overheat

Postby estilian [OP] » February 8th 2015, 10:13pm

Unfortunately today was one of those days I want to forget or go back to the past and skip it... My family and I decided to go on a ski vacation for one week and as we have a 4 months baby our luggage looks like we are moving out in another house - 6 suitcases, 3 bags, swing, baby bath pool, stroller, sledge, ski and equipment and many many other - a perfect possibility to test the volume capacity of the Astro :)
And right when everything was like a dream my precious Astro started to act weird on the highway. I have traveled for about 20-30 miles when suddenly the heat from the blowers disappeared. Just a few minutes later I noticed the temperature gauge is rising very fast. It didn't manage to reach the red zone, but on it went up to the half between the middle of the gauge and the maximum red... I pulled over and stopped the engine. When I opened the bonnet I saw that the coolant in the expansion tank is boiling and pouring out of it. It was very very strange as I never ever had problems with coolant before. Never lost even a drop of water - the coolant was always up to the top and filled with quality antifreeze. I waited for about 10-15 minutes, then I opened the cap of the radiator (very very gentle to prevent water explosion because of the high pressure) and started to refill the coolant system. It took about 3-4 liters of water until it got full. Then I started the engine again - the gauge was showing exactly where it should point on optimal temp. I drove for 10 more miles and the problem appeared again, but this time I stopped earlier to prevent damage of the engine. Same procedure again, this time the system took about liter and a half. After I did this for 5-6 times I noticed something - it was happening when I rev up my engine and when I'm driving uphill and also I noticed that the hose going from the radiator to the thermostat is not as hot as all the other hoses... seemed like it's not filled with water. It's important to mention that it's winter here and the outside temp is below zero...
After so many attempts to keep the engine cooled I decided that for some reason there is air coming in the coolant system that is blocking the cooled water to go the inner circle of the coolant system. So to assure that the air is released I left the radiator cap loosened just to the position before it's removed. This way the air was going through the pipe to the expansion tank. With this little modification I managed to travel for almost 200 miles without having to refill the system and keeping the coolant always below 95C (203F) - I was checking the temp on my phone using an OBDII reader to be sure that the values are correct.

Now the problem is that I'm 300 miles away from home with a very beautiful and broken Astro... and I'm not sure what is the reason for my troubles! I have two suggestions:
1. The thermostat which I replaced 2 months ago has failed and now it's staying always in a closed position not allowing the cooled water to enter the engine. But again - this does not explain why the hose was not hot, why the boiling coolant was pouring out and why the opening of the radiator cap actually helped!
2. The second and maybe worst scenario - the head gasket is damaged allowing the air from the cylinders to enter the coolant system making an air balloon in the hose between the radiator and the thermostat (there, because it's the highest part of the entire system). But again - if this is the case, then why the hoses were not inflated and why it happened so suddenly.

I accept any advice as I need to get back home at the end of the week and I don't want to see my wife and my baby crying for 8 hours while I'm trying to make the Astro run.
Original Poster [OP]
User avatar
estilian
Fueling (1/4 tank)
Fueling (1/4 tank)
Years of Membership: estilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full years
Posts: 30
Topics: 6
Joined: November 2014
Location: Sofia, Bulgaria (Eastern Europe)
Gender: Male
Alias (AKA):
Van Model Year: 1999
Van Make/Model: Chevrolet Astro
Extra Info: Transcar

Re: Problem on a highway - unexplained overheat

Postby chevymaher » February 8th 2015, 11:13pm

No the top hose not being hot explains everything. It is not circulating the coolant and boiling over. T Stat is closed or the water pump is failed which is not first choice they don't fall apart inside often. But since it isnt getting heat either and both overheating and lack of heat happened at the same time. I would lean toward that being the problem. Vane sheared off inside. It possibly froze and sheared it off starting.
If it was a head gasket alone the top hose would still be hot.
Image
User avatar
chevymaher
Team Leader
Team Leader
Firing on 8 Cylinders (L7)
Firing on 8 Cylinders (L7)
Years of Membership: chevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full years
Posts: 14286
Topics: 91
Images: 94
Joined: November 2010
Gender: Male
Alias (AKA): chevymaher
Van Model Year: 1994
Van Make/Model: GMC Safari
Extra Info: SLE RWD Mercruiser

Re: Problem on a highway - unexplained overheat

Postby redfury » February 8th 2015, 11:22pm

I'd smell your coolant to see if you can detect exhaust gases, as well as make sure you check your oil! You are either blowing it out the exhaust pipe, or it's coming out from seepage and getting burned off under the van. Try to identify where the water is going the best you can. Exhaust pipe should be somewhat sooty all around, but not wet after the van has sat long enough for water to evaporate. If the van is cold and you can feel wetness around the exhaust tip ( inside ), give it a quick lick and see if it's sweet tasting at all ( it's probably not going to be pleasant, but we are looking for traces of antifreeze in the exhaust ). Relieving pressure probably allowed the exhaust gasses to be blown out of the cap, and the cap is going to release pressure if it builds above 16psi anyway, so you won't have expanding hoses unless you have a problem with the cap.

Boiling coolant with a closed system and not with the open and no large loss of coolant though....boiling was probably a result of the loss of coolant...likely being sucked into the combustion chamber.

The lack of heat means you've lose pressure in the cooling system, or you have lost coolant enough for there to be too little to send to the heater core. Did you get heat again once you refilled? Then that's your answer...lack of coolant to heat the cabin.

My best guess based on the variables would be an intake gasket leak. If you aren't seeing a loss of coolant externally, then you are burning it by sucking it into the combustion chamber.

This really isn't a very good situation, as you are likely going to get coolant build up in the affected cylinders as it sits. I'd make arrangements in case of a catastrophic failure on the way home. You may want to try a stop leak type product, as much as I hate them. Silver seal has worked for me in the past. Hopefully others here can help come up with something that will get you home or help you find the cause.
A temporary fix usually becomes a permanent solution, therefore it does not exist.
doghouse removal by me!http://www.youtube.com/watch?v=uIJ0kuROlbU
User avatar
redfury
U.S. Armed Forces
U.S. Armed Forces
Firing on 8 Cylinders (L3)
Firing on 8 Cylinders (L3)
Years of Membership: redfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full years
Posts: 2958
Topics: 53
Images: 13
Joined: December 2010
Location: isanti, mn
Gender: Male
Alias (AKA): Mike
Van Model Year: 1998
Van Make/Model: Chevrolet Astro
Extra Info: LT 5.7L 4wd

Re: Problem on a highway - unexplained overheat

Postby redfury » February 8th 2015, 11:23pm

chevymaher wrote:No the top hose not being hot explains everything. It is not circulating the coolant and boiling over. T Stat is closed or the water pump is failed which is not first choice they don't fall apart inside often. But since it isnt getting heat either and both overheating and lack of heat happened at the same time. I would lean toward that being the problem. Vane sheared off inside. It poissibly froze and sheared it off starting.
If it was a head gasket alone the top hose would still be hot.


A bad water pump wouldn't explain how he was able to maintain temps with the cap off though. If the T stat was closed, he'd still have an overheat issue due to lack of coolant circulation, and he's loosing a lot of coolant while the system is under pressure.
A temporary fix usually becomes a permanent solution, therefore it does not exist.
doghouse removal by me!http://www.youtube.com/watch?v=uIJ0kuROlbU
User avatar
redfury
U.S. Armed Forces
U.S. Armed Forces
Firing on 8 Cylinders (L3)
Firing on 8 Cylinders (L3)
Years of Membership: redfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full years
Posts: 2958
Topics: 53
Images: 13
Joined: December 2010
Location: isanti, mn
Gender: Male
Alias (AKA): Mike
Van Model Year: 1998
Van Make/Model: Chevrolet Astro
Extra Info: LT 5.7L 4wd

Re: Problem on a highway - unexplained overheat

Postby estilian [OP] » February 8th 2015, 11:32pm

It's not the water pump cause I can feel the water flow accelerating when I rev up the engine and also when the radiator cap was opened I could see how the coolant level was entering deeper when I was accelerating.

Do you think it's a good idea to take off the thermostat and drill a few wholes on it?! This should do the job until I get home and replace it with a new one?!

And another important question - is it possible that I've damaged the engine somehow with this overheating?! My gauge is in Celsius where 40 is minimum, 100 is middle and 125 is maximum. Only once the temp reached a value just before the red zone on the gauge (check the attached photo) - I guess it's about 110C but I stopped the engine in less then 20-30 sec after it started to increase the temp. Also - I'm sure that the coolant system didn't stay empty or dry - it was hot, but always full with coolant. Hope this american beauty is able to handle some hot :)

Image1.jpg
Image1.jpg (84.92 KiB) Viewed 3728 times


redfury wrote:If the T stat was closed, he'd still have an overheat issue due to lack of coolant circulation, and he's loosing a lot of coolant while the system is under pressure.

I also started to drive slowly - never reached RPM higher then 1800-2000 for the entire trip and the temp was moving between 80 and 100C on the gauge all the time (87-92C on the phone while checking live-data through OBDII), also the car continued loosing my heat on the blowers from time to time... So the opened cap didn't help much, it just allowed me to reach my destination without having the engine boiled ;) Few hours after I arrived I tried to refill the system - it only took 1 liter of coolant so it seems that I also haven't lost coolant with the loosened cap.

Another important facts - no white smoke is coming from the exhaust, the engine is starting easily and it's working as smooth as it should... I guess that with a blown head gasket it wouldn't do so, am I right?
Last edited by estilian on February 8th 2015, 11:47pm, edited 1 time in total.
Original Poster [OP]
User avatar
estilian
Fueling (1/4 tank)
Fueling (1/4 tank)
Years of Membership: estilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full years
Posts: 30
Topics: 6
Joined: November 2014
Location: Sofia, Bulgaria (Eastern Europe)
Gender: Male
Alias (AKA):
Van Model Year: 1999
Van Make/Model: Chevrolet Astro
Extra Info: Transcar

Re: Problem on a highway - unexplained overheat

Postby pauldeere » February 8th 2015, 11:45pm

I agree with the bad thermostat theory. Sounds like you caught the heat in sufficent time to prevent engine damage. I know this sounds easy being far from home but replacing the thermostat is your only fix. good Luck
pauldeere
U.S. Armed Forces
U.S. Armed Forces
Firing on 1 Cylinder (L1)
Firing on 1 Cylinder (L1)
Years of Membership: pauldeere has been a member for 6 full yearspauldeere has been a member for 6 full yearspauldeere has been a member for 6 full yearspauldeere has been a member for 6 full yearspauldeere has been a member for 6 full yearspauldeere has been a member for 6 full years
Posts: 175
Topics: 18
Joined: August 2014
Alias (AKA): Tall Paul

Re: Problem on a highway - unexplained overheat

Postby chevymaher » February 8th 2015, 11:48pm

redfury wrote:A bad water pump wouldn't explain how he was able to maintain temps with the cap off though. If the T stat was closed, he'd still have an overheat issue due to lack of coolant circulation, and he's loosing a lot of coolant while the system is under pressure.

I have seen it happen that way. Under pressure it spitting it out the bottle untill it is to low to cool at all. Not under pressure it becomes low then boils slowly. Allowing air to escape without liquid through the cap. And the boiling action itself cools it. For a while as he described.

But that is neither here nor there. Your prognosis is very viable. The fact it has no heat EVER full or empty leads me to believe it is, or originally was a circulation issue. Once it is full it should have heat like mad untill it is low again. It is overheating it should be throwing heat like a blast furnace. T Stat closed or not. Now once it overheated heads do tend to warp and leak blow gaskets.

He never mentioned a smoke screen following the van. Which would be obvious to him, if it was loosing that much coolant that fast in cold temps. Hey I can't see cars 10 miles back. I just making guesses based on the story being told.
I ain't god but that is my opinion based on what he described.
It will come out in the wash as they say.
Image
User avatar
chevymaher
Team Leader
Team Leader
Firing on 8 Cylinders (L7)
Firing on 8 Cylinders (L7)
Years of Membership: chevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full years
Posts: 14286
Topics: 91
Images: 94
Joined: November 2010
Gender: Male
Alias (AKA): chevymaher
Van Model Year: 1994
Van Make/Model: GMC Safari
Extra Info: SLE RWD Mercruiser

Re: Problem on a highway - unexplained overheat

Postby kennysmoke » February 9th 2015, 12:45am

I'd start with changing the t-stat... it's a cheap and fairly easy fix... every time I've had a no cabin heat/ overheat condition with no signs of external leakage on any of the vehicles I've owned the t-stat was the culprit... continuing to run it hot could have caused many other problems, but if you're lucky you may have caught it in time...

http://shop.advanceautoparts.com/p/stan ... efZC=14094
"Live Free Or Die" Image
User avatar
kennysmoke
Blue Status (L2)
Blue Status (L2)
Years of Membership: kennysmoke has been a member for 10 full yearskennysmoke has been a member for 10 full yearskennysmoke has been a member for 10 full yearskennysmoke has been a member for 10 full yearskennysmoke has been a member for 10 full yearskennysmoke has been a member for 10 full yearskennysmoke has been a member for 10 full yearskennysmoke has been a member for 10 full yearskennysmoke has been a member for 10 full yearskennysmoke has been a member for 10 full years
Posts: 1019
Topics: 68
Images: 7
Joined: July 2011
Location: Lockport NY
Gender: Male
Alias (AKA): kennysmoke
Van Model Year: 2003
Van Make/Model: Chevrolet Astro
Extra Info: AWD Tow Pakage

Re: Problem on a highway - unexplained overheat

Postby Lumpy » February 9th 2015, 1:29am

estilian wrote:
Do you think it's a good idea to take off the thermostat and drill a few wholes on it?! This should do the job until I get home and replace it with a new one?!



I think it's a good idea to replace the thermostat. Cheap part. If you're in a position and have the tools to remove the old one and drill holes, I would think you're in a position and have the tools to simply replace it. Or at least limp it down the mountain to some place where you can buy a new thermostat.

Start by knowing the simplest and cheapest part is ok (the thermostat). Then troubleshoot forward from there.


Lump
User avatar
Lumpy
Deprived Privileges
Deprived Privileges
Firing on 8 Cylinders (L7)
Firing on 8 Cylinders (L7)
Years of Membership: Lumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full years
Posts: 10996
Topics: 261
Joined: April 2010
Location: Phoenix AZ USA
Gender: Male
Alias (AKA):
Van Model Year: 1989
Van Make/Model: Chevrolet Astro
Extra Info: 11 in. lift Camo

Re: Problem on a highway - unexplained overheat

Postby estilian [OP] » February 9th 2015, 12:26pm

chevymaher wrote:The fact it has no heat EVER full or empty leads me to believe it is, or originally was a circulation issue. Once it is full it should have heat like mad untill it is low again. It is overheating it should be throwing heat like a blast furnace. T Stat closed or not. Now once it overheated heads do tend to warp and leak blow gaskets.


Ok, maybe I didn't describe it very well. The situation was like this: at the beginning everything was ok - normal temp, good hot air blowing from the vents. Then first sign - heat inside the car disappears. And it was happening very fast - within less then a minute the air was changing from extreme hot to cold outside temp. Less then a minute after this the temp gauge on the dashboard is starting to rise quickly and by quickly I mean from 80 to 110C for about 30 secs. When I see this I always pulled over and stopped the engine (less then a minute after the temp gauge started to rise). At this moment I was unable to do much as the coolant is boiling and parts of it was pouring out of the expansion tank because of the pressure made by the high temp in the system. To prevent loosing it all I was trying to carefully lose the radiator cap - very slowly, just enough to release the pressure and not making it run out too fast to the expansion tank which was full to it's top. With this procedure within a minute I was able to fully open the radiator cap, refill with 1-2 liters of coolant and run again the engine. After refilling the system everything is perfect for about 5-10 minutes of driving - normal coolant temp (80-85C), good heat inside the car. The time it took before repeating the same problem was depending on just one simple thing - load of the engine. If I was going uphill or using too much acceleration the heat from the blowers was disappearing within 2-3 minutes and soon - overheating the coolant. If I left the car idle or driving with about 100-110km/h with low RPM it could continue working without overheat for a very long time.


chevymaher wrote:He never mentioned a smoke screen following the van.

Nope - absolutely nothing! And by nothing I mean pure invisible exhaust even on idle or high revs. I tried to make a cold start this morning and no white smoke was visible... this makes me believe that the coolant is not entering the engine. I forgot to check the condition of the oil, but I will do this in an hour and will post update.

Lumpy wrote:I would think you're in a position and have the tools to simply replace it

Lump, as always, I have enough tools to disassemble the entire Astro here in the mountains... but the problem is that I live in a country where Chevrolet Astro is something like UFO - noone has ever seen one of those before... so you can imagine the problem with finding parts for it. Last time I needed a thermostat I spent 6 days trying to find one in the capital with no luck then I ordered one from ebay... So I'm absolutely sure I won't find a proper thermostat neither in the mountains, nor when I get back home :) So for the moment drilling the old one is the only option :)
Original Poster [OP]
User avatar
estilian
Fueling (1/4 tank)
Fueling (1/4 tank)
Years of Membership: estilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full years
Posts: 30
Topics: 6
Joined: November 2014
Location: Sofia, Bulgaria (Eastern Europe)
Gender: Male
Alias (AKA):
Van Model Year: 1999
Van Make/Model: Chevrolet Astro
Extra Info: Transcar

Re: Problem on a highway - unexplained overheat

Postby chevymaher » February 9th 2015, 12:41pm

From that descripyion, Redfury may be right. open the radiator and let it run. It you see a constant bubbling in the radiator it is a leaking head gasket compression getting in there. Stand on the brake and give it some gas with it full the cap open and the hood open. You can see the radiator from the drivers seat. If it becomes mount Vesuvius you found it.

If not, With it warm and idling look in there. Letting it warm up while open look and see if it has circulation. If it does close it and just let it run and look under it see if it is leaking. Rear heater hoses like to do that.

Good luck on the hunt and hope it is something simpler to fix that a head gasket. And check the oil to make sure it isnt getting in there. Coffee colored oil is cracked head or head gasket, intake gasket something like those.
Image
User avatar
chevymaher
Team Leader
Team Leader
Firing on 8 Cylinders (L7)
Firing on 8 Cylinders (L7)
Years of Membership: chevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full years
Posts: 14286
Topics: 91
Images: 94
Joined: November 2010
Gender: Male
Alias (AKA): chevymaher
Van Model Year: 1994
Van Make/Model: GMC Safari
Extra Info: SLE RWD Mercruiser

Re: Problem on a highway - unexplained overheat

Postby Lumpy » February 9th 2015, 3:16pm

estilian wrote:
... I live in a country where Chevrolet Astro is something like UFO - noone has ever seen one of those before... so you can imagine the problem with finding parts for it. Last time I needed a thermostat I spent 6 days trying to find one in the capital with no luck then I ordered one from ebay...



Our thermostats fit several million vehicles of all makes and models made from the 1940s through today. ALL of our vans are no longer in production. So I suggest developing a good cross reference as to which parts from which cars will fit your particular van. I have a long list of "This part from XX year Make/Model car/truck will fit my 89". I keep it at home and on my phone. If I'm in the U-pull or LAPS or cruising through online classified ads, and I see a "Germ Dehibernator Cut Back Bypass Toggle" from a 1949 Kaiser, I'll know it fits.


Lump
User avatar
Lumpy
Deprived Privileges
Deprived Privileges
Firing on 8 Cylinders (L7)
Firing on 8 Cylinders (L7)
Years of Membership: Lumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full years
Posts: 10996
Topics: 261
Joined: April 2010
Location: Phoenix AZ USA
Gender: Male
Alias (AKA):
Van Model Year: 1989
Van Make/Model: Chevrolet Astro
Extra Info: 11 in. lift Camo

Re: Problem on a highway - unexplained overheat

Postby Mmusicman » February 9th 2015, 3:54pm

estilian wrote:I have traveled for about 20-30 miles when suddenly the heat from the blowers disappeared. Just a few minutes later I noticed the temperature gauge is rising very fast..

What you describe sounds like the water pump possibly failing, or failed (if you lost your heat too). When a thermostat closes, the waterpump still curculates water in the short-circuited block. Your heater picks up the heated coolant from the back of the block BEFORE it reaches the thermostat. Personally, I have never had a water pump fail, but I suppose it could happen.

If your heat worked however, and you suddenly overheated on the highway, then this would most certainly be the thermostat stuck! This happened to me once on the highway, and I had to be towed home.

Yes, you can drill small holes in the new thermostat! A lot of people do it... I have always done it. The idea is to not shock the engine with cold water when the thermostat finally opens... and to keep a certain small amount of flow always going. I think I have even seen some new high-performance thermostats with the holes already drilled. Regardless, it is easy, and beneficial. But note it will take you longer to get to full operating temperature... as well as taking you longer to get heat!

Thermostats are cheap and easy to change! They can become sticky and intermittent too... and if I even remotely suspect an issue.. I'll change it! It's cheap insurance to keep your motor from overheating... which can be one of the single most detrimental things you can do to the 4.3.

Let us know what you find!
Image
2000 Astro LS 4x4 | NP233 | 31" LT265/70R17 Tires | 8" LIFT | 10" TOTAL
92 Chevy Astro Cargo Shorty | V8-350
http://www.CruisinSouthFlorida.com
User avatar
Mmusicman
V8 Swap Achievement
V8 Swap Achievement
Firing on 1 Cylinder (L6)
Firing on 1 Cylinder (L6)
Years of Membership: Mmusicman has been a member for 8 full yearsMmusicman has been a member for 8 full yearsMmusicman has been a member for 8 full yearsMmusicman has been a member for 8 full yearsMmusicman has been a member for 8 full yearsMmusicman has been a member for 8 full yearsMmusicman has been a member for 8 full yearsMmusicman has been a member for 8 full years
Posts: 5113
Topics: 75
Images: 61
Joined: June 2013
Location: Ft. Lauderdale, Florida
Gender: Male
Alias (AKA): Scott
Van Model Year: 2000
Van Make/Model: Chevrolet Astro
Extra Info: 2000 4x4 - 92 V8-350

Re: Problem on a highway - unexplained overheat

Postby estilian [OP] » February 9th 2015, 5:58pm

Ok - I've checked the oil... it looks perfectly clean. No foam, no strange parts in it and the color was just fine - a little darker then a new bottle of oil, but it has 5000km on it, so I think it's ok. Also - we did a cold start again. Nothing coming from the exhaust pipe - neither white smoke, smells or anything else - as if the car is still with the engine shut.

As for the test that chevymaher suggested - I noticed bubbles in the system only when the coolant was boiling. Every time after a refill I was checking with a radiator cap opened and there wasn't a constant appear of bubbles - only small bubbles coming after a 5-6 minutes of work which is maybe air being stuck somewhere.
The other test - with letting the water explode from the cap... after all I drove for 200 miles with the cap opened and almost none water did splashed. So I think this is also negative.
I also don't see any leaks under the van... at least there is snow everywhere so a leaking blue antifreeze would be easy to find. Only place is under the expansion tank, but when I arrived the temp was at 100C so the coolant was boiling and I guess some coolant came out of it.

I will try to run for some miles tomorrow and will see how it behaves. As for the water pump and the circulation - I still don't think it's it because even after the first several overheats, when I add normal water and run the engine it immediately cooled the system and I can definitely feel the water flow in the pipes, except in the one coming from the radiator to the thermostat.

Lump - can you please check and tell me the size of thermostat? I think the only thing that's crucial is the diameter of the ring?! It would be great to know it in centimeters but inches would be fine as well :) I will try to look for some parts shop in the nearest city which is 40km from here :)
Original Poster [OP]
User avatar
estilian
Fueling (1/4 tank)
Fueling (1/4 tank)
Years of Membership: estilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full yearsestilian has been a member for 6 full years
Posts: 30
Topics: 6
Joined: November 2014
Location: Sofia, Bulgaria (Eastern Europe)
Gender: Male
Alias (AKA):
Van Model Year: 1999
Van Make/Model: Chevrolet Astro
Extra Info: Transcar

Re: Problem on a highway - unexplained overheat

Postby Lumpy » February 9th 2015, 6:32pm

estilian wrote:
Lump - can you please check and tell me the size of thermostat? I think the only thing that's crucial is the diameter of the ring?! It would be great to know it in centimeters but inches would be fine as well :) I will try to look for some parts shop in the nearest city which is 40km from here :)


I might have one in the shop, I'll check and measure.

In the mean time, here's a short list of cars with thermostats that will interchange with my 89. It looks like nearly any Chevrolet from 1934 to 1999 will fit. Perhaps one or more of these make/year cars is more popular for parts where you are.


ALFA ROMEO (1961 - 1982)
AM GENERAL (1969 - 1974)
AMERICAN MOTORS (1961 - 1988)
AUSTIN (1960 - 1970)
AUSTIN-HEALEY (1953 - 1970)
BRICKLIN (1974 - 1975)
BUICK (1933 - 1993)
CADILLAC (1963 - 1995)
CHECKER (1959 - 1982)
CHEVROLET (1934 - 1999)
CHRYSLER (1978 - 1983)
DODGE (1960 - 2003)
FARGO (1964 - 1972)
FIAT (1960 - 1974)
FORD (1949 - 2003)
GEO (1989 - 1993)
GMC (1955 - 1999)
HILLMAN (1960 - 1967)
HYUNDAI (2000 - 2002)
JAGUAR (1949 - 1971)
JEEP (1956 - 2005)
KAISER-FRAZER (1947 - 1951)
MAZDA (1994 - 1995)
MERCEDES-BENZ 1955
MERCURY (1949 - 1987)
MG (1955 - 1980)
MORGAN (1968 - 1981)
MORRIS (1954 - 1971)
OLDSMOBILE (1964 - 1993)
OPEL (1968 - 1969)
PACKARD (1955 - 1956)
PLYMOUTH (1963 - 1983)
PONTIAC (1964 - 1993)
SAAB (1971 - 1976)
TRIUMPH (1967 - 1981)
WORKHORSE (2010 - 2011)


Lump
User avatar
Lumpy
Deprived Privileges
Deprived Privileges
Firing on 8 Cylinders (L7)
Firing on 8 Cylinders (L7)
Years of Membership: Lumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full years
Posts: 10996
Topics: 261
Joined: April 2010
Location: Phoenix AZ USA
Gender: Male
Alias (AKA):
Van Model Year: 1989
Van Make/Model: Chevrolet Astro
Extra Info: 11 in. lift Camo

Re: Problem on a highway - unexplained overheat

Postby chevymaher » February 9th 2015, 7:11pm

I remembered a older thread guy talked about this. your van takes a different type T-Stat. with a extension at the bottom which extends into a separate layer of the intake.I will post the 2 separate types when I am done working and upstairs on a real computer. This one locks up if I do to much.
30 year old laptop with the screen ripped off. But it good enough for non pic and downloading 6 windows open stuff.
Image
User avatar
chevymaher
Team Leader
Team Leader
Firing on 8 Cylinders (L7)
Firing on 8 Cylinders (L7)
Years of Membership: chevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full yearschevymaher has been a member for 10 full years
Posts: 14286
Topics: 91
Images: 94
Joined: November 2010
Gender: Male
Alias (AKA): chevymaher
Van Model Year: 1994
Van Make/Model: GMC Safari
Extra Info: SLE RWD Mercruiser

Re: Problem on a highway - unexplained overheat

Postby Lumpy » February 9th 2015, 7:50pm

Here's a short list of the one's that fit a 99 Astro with bottom bypass -


CADILLAC ESCALADE (1999 - 2000)
CHEVROLET ASTRO (1996 - 2005)
CHEVROLET BLAZER (1996 - 2005)
CHEVROLET C1500 PICKUP (1996 - 1999)
CHEVROLET C1500 SUBURBAN (1996 - 1999)
CHEVROLET C2500 PICKUP (1996 - 2000)
CHEVROLET C2500 SUBURBAN (1996 - 1999)
CHEVROLET C35 (1999 - 2000)
CHEVROLET C3500 PICKUP (1996 - 2000)
CHEVROLET CARGO VAN (1997 - 1999)
CHEVROLET EXPRESS 1500 (1996 - 2011)
CHEVROLET EXPRESS 2500 (1996 - 2005)
CHEVROLET EXPRESS 3500 (1996 - 2002)
CHEVROLET EXPRESS CARGO (2010 - 2011)
CHEVROLET G30 2002
CHEVROLET K1500 PICKUP (1996 - 1999)
CHEVROLET K1500 SUBURBAN (1996 - 1999)
CHEVROLET K2500 PICKUP (1996 - 2000)
CHEVROLET K2500 SUBURBAN (1996 - 1999)
CHEVROLET K3500 PICKUP (1996 - 2000)
CHEVROLET P30 (1996 - 1999)
CHEVROLET S10 PICKUP (1996 - 2004)
CHEVROLET SILVERADO 1500 (1999 - 2011)
CHEVROLET SILVERADO 1500 CLASSIC 2007
CHEVROLET TAHOE (1996 - 2000)
CHEVROLET W3500 TILTMASTER (1996 - 2003)
CHEVROLET W4500 TILTMASTER (1998 - 2003)
GMC C1500 PICKUP (1996 - 1999)
GMC C1500 SUBURBAN (1996 - 1999)
GMC C2500 PICKUP (1996 - 2000)
GMC C2500 SUBURBAN (1996 - 1999)
GMC C3500 PICKUP (1996 - 2000)
GMC JIMMY (1996 - 2005)
GMC K1500 PICKUP (1996 - 1999)
GMC K1500 SUBURBAN (1996 - 1999)
GMC K2500 PICKUP (1996 - 2000)
GMC K2500 SUBURBAN (1996 - 1999)
GMC K3500 (1996 - 2000)
GMC P3500 (1996 - 1999)
GMC SAFARI (1996 - 2005)
GMC SAVANA 1500 (1996 - 2011)
GMC SAVANA 2500 (1996 - 2005)
GMC SAVANA 3500 (1997 - 2002)
GMC SIERRA 1500 (1999 - 2011)
GMC SIERRA 1500 CLASSIC 2007
GMC SONOMA (1996 - 2004)
GMC W3500 FORWARD (2000 - 2003)
GMC W4500 FORWARD (1998 - 2002)
GMC YUKON (1996 - 1999)
ISUZU HOMBRE (1997 - 2000)
ISUZU NPR (1993 - 2002)
ISUZU NPR-HD (1999 - 2002)
OLDSMOBILE BRAVADA (1996 - 2001)
VOLVO C30 2011
VOLVO C70 2011
VOLVO S40 2011
VOLVO V50 2011
WORKHORSE P32 (2001 - 2002)


Lump
User avatar
Lumpy
Deprived Privileges
Deprived Privileges
Firing on 8 Cylinders (L7)
Firing on 8 Cylinders (L7)
Years of Membership: Lumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full years
Posts: 10996
Topics: 261
Joined: April 2010
Location: Phoenix AZ USA
Gender: Male
Alias (AKA):
Van Model Year: 1989
Van Make/Model: Chevrolet Astro
Extra Info: 11 in. lift Camo

Re: Problem on a highway - unexplained overheat

Postby Mmusicman » February 9th 2015, 9:14pm

You ABSOLUTELY need the "correct" thermostat with the "bypass valve"!

An older t-stat might fit, but without the bypass valve shut, you will send your circulation short-circuited in circles rather than thru the radiator.

Just order the one made for your year van.

Image

Here's a good photo showing how it works:

Image
Image
2000 Astro LS 4x4 | NP233 | 31" LT265/70R17 Tires | 8" LIFT | 10" TOTAL
92 Chevy Astro Cargo Shorty | V8-350
http://www.CruisinSouthFlorida.com
User avatar
Mmusicman
V8 Swap Achievement
V8 Swap Achievement
Firing on 1 Cylinder (L6)
Firing on 1 Cylinder (L6)
Years of Membership: Mmusicman has been a member for 8 full yearsMmusicman has been a member for 8 full yearsMmusicman has been a member for 8 full yearsMmusicman has been a member for 8 full yearsMmusicman has been a member for 8 full yearsMmusicman has been a member for 8 full yearsMmusicman has been a member for 8 full yearsMmusicman has been a member for 8 full years
Posts: 5113
Topics: 75
Images: 61
Joined: June 2013
Location: Ft. Lauderdale, Florida
Gender: Male
Alias (AKA): Scott
Van Model Year: 2000
Van Make/Model: Chevrolet Astro
Extra Info: 2000 4x4 - 92 V8-350

Re: Problem on a highway - unexplained overheat

Postby Lumpy » February 9th 2015, 9:54pm

Mmusicman wrote:
Just order the one made for your year van.



And since you're broke down, in the mountains, in Bulgaria, ask for "Next 30 minutes delivery".


Lump
User avatar
Lumpy
Deprived Privileges
Deprived Privileges
Firing on 8 Cylinders (L7)
Firing on 8 Cylinders (L7)
Years of Membership: Lumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full yearsLumpy has been a member for 11 full years
Posts: 10996
Topics: 261
Joined: April 2010
Location: Phoenix AZ USA
Gender: Male
Alias (AKA):
Van Model Year: 1989
Van Make/Model: Chevrolet Astro
Extra Info: 11 in. lift Camo

Re: Problem on a highway - unexplained overheat

Postby redfury » February 10th 2015, 5:38am

Well, by everything described, I agree with replacing the T stat first and see where it gets you, though if it were stuck shut, you'd still think you'd have an overheat condition....where is the coolant going? Unless the coolant is getting forced out of the system, which would mean that the overflow should be filled to the top and losing the coolant from there. You'd think that you'd see some kind of evidence under the van if that were the case, maybe not dripping off into the snow, but you'd see an unusual amount of wetness on the passenger side vs. the drivers side of the vans bottom. I'd give the van a good look underneath for any kind of signs of antifreeze residue and if I found it, then I would have to think that the boiling off of coolant out of the overflow due to a sticking thermostat would be the culprit.

However, I'm having difficulty in diagnosing a stuck thermostat when temps are good when the system isn't under pressure. Unless the thermostat isn't sticking, but it's broken. The nice thing is, you can pull the thermostat out and not have to worry about the gasket, since it's a rubber ring around the T stat. You could remove it, and see how it's acting in a pot of water on the stove.

I pulled the T stat out of my wife's Explorer because the temp gauge would cycle from normal to a little hotter and back to normal, and repeat . Pulled it out and discovered that one leg had pulled away from the base somehow and it cause the T stat to cycle the pill due to the flow of water around it. Functionally broken.
A temporary fix usually becomes a permanent solution, therefore it does not exist.
doghouse removal by me!http://www.youtube.com/watch?v=uIJ0kuROlbU
User avatar
redfury
U.S. Armed Forces
U.S. Armed Forces
Firing on 8 Cylinders (L3)
Firing on 8 Cylinders (L3)
Years of Membership: redfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full yearsredfury has been a member for 10 full years
Posts: 2958
Topics: 53
Images: 13
Joined: December 2010
Location: isanti, mn
Gender: Male
Alias (AKA): Mike
Van Model Year: 1998
Van Make/Model: Chevrolet Astro
Extra Info: LT 5.7L 4wd

Next

 
  • Related topics
    Replies
    Views
    Last post

Return to Engines

It is currently August 5th 2021, 1:44am

Engines Forum
Engine Repairs, Modifications, Diagnostics, Tuning, Upgrading, Questions.

<a href="https://ad.doubleclick.net/ddm/trackclk/N8334.275400VERTICALSCOPEINC./B20209277.204028354;dc_trk_aid=407011718;dc_trk_cid=94070067;dc_lat=;dc_rdid=;tag_for_child_directed_treatment="target="_blank"><img src="https://tpc.googlesyndication.com/pagead/imgad?id=CICAgKDrrqWwMRCAARgcKAEyCN4sAjjtai4k" border="0" align="right">
<IMG SRC="https://ad.doubleclick.net/ddm/trackimp/N8334.275400VERTICALSCOPEINC./B20209277.204028354;dc_trk_aid=407011718;dc_trk_cid=94070067;ord=;dc_lat=;dc_rdid=;tag_for_child_directed_treatment=?" BORDER="0" HEIGHT="1" WIDTH="1" ALT="Advertisement">
Moderator: chevy57bert
To create a new topic in Engines, click this button:
Previous topic Next topic
Recent Image Attachments
Attached by:
AngryPunk
in Engines
Views: 2947
Comments: 74
Date: Jul 26 '21
Time: 4:28am
» Read last comment
Attached by:
OldSchoolNoe
in Engines
Views: 65
Comments: 0
Date: Jul 26 '21
Time: 1:20am
» Read last comment
Attached by:
AngryPunk
in Engines
Views: 2947
Comments: 74
Date: Jul 25 '21
Time: 4:09am
» Read last comment
Attached by:
detroit102176
in Engines
Views: 128
Comments: 4
Date: Jul 24 '21
Time: 4:28pm
» Read last comment
Attached by:
Attached by: Godron629
Godron629
in Engines
Views: 186
Comments: 10
Date: Jul 23 '21
Time: 5:44pm
» Read last comment
Sponsors

Who is online

Users browsing this forum: No registered users and 44 guests