Chevy Astro and GMC Safari Forum banner

2005 Astro Overheating

2K views 17 replies 8 participants last post by  bradyalderin 
#1 ·
I have tried and tried searching for the answer to this question but couldn't find it. I am sure this has been asked before and if someone has a link to the answer that would be amazing. However I just bout a 2005 Astro AWD drove it for 2 days (couple hundred miles) with no issues. Just yesterday it started to over heat. I see that Intake manifold gasket is a huge issue with these things, but not sure if it is for the 2005? If so how do I check to see if it is the intake manifold gasket? I can't seem to find any leaks around it. I did have a coolant leak but I believe that was because I over filled the coolant overflow tank. There is coolant in the radiator and its full, but also full of sludge, so I know I need to flush it as well. I am an absolute newb to Astros. Thanks for any help!
 
#2 ·
bradyalderin said:
... Just yesterday it started to over heat.
Were you going by the gauge or was there some real undisclosed problem ?

Suggest a good steam or wash down and dry, then check weep holes in water pump and back of engine.
Yes, 2nd Gen Astros and Safaris have some hi mileage intake manifold issues. Hope that's not your situation.
 
#5 ·
I did. It's all I had and my only vehicle. Is that bad ? Can I just flush the system? I just drove back from work and it didn't over heat. When I drove to work this morning the gauges were pegged indicating it overheated but back home it didn't even come close. I also tried using the heater and it did not work.
 
#6 ·
These vans use Dex-cool which is orange. Mixing the green with the orange is a no go. It will cause the van to over heat. A full system flush is needed.
 
#8 ·
At the very least, you need to flush the cooling system. Drain the radiator, drain the block as much as you can, drain the heater core. Refill with flush stuff and water and run for a while, then drain and rinse. Replace the thermostat, replace the upper and lower radiator hoses if they don't look new and replace the lower intake manifold gaskets with the Fel-Pro set that ends in T - that's the plastic-coated metal set that lasts longer than the OEM-style gaskets.

When you have reassembled everything except the thermostat and upper radiator hose, fill the block through the thermostat hole, then install the t-stat, housing and upper hose. Fill the radiator. Now get the passenger front side up as high as you can and do several heat/cool cycles to burp out air - it will take a few because the rad cap is not the highest point in the system.
 
#9 ·
Leeann_93 said:
replace the lower intake manifold gaskets with the Fel-Pro set that ends in T - that's the plastic-coated metal set that lasts longer than the OEM-style gaskets.
x2, these guys https://amzn.to/32UGVqM
 
#10 ·
Dexcool has been compatible with most other coolants for over 10 years.But not bottom of the line "green".It is compatible with all "universal" coolants.Anyway,that looks like rust to me,which did not just happen.If you plan on keeping van,I would recommend flushing radiator,heater core and block.Time consuming and messy.If you cannot,there are other options.BTY,the biggest thing about dexcool was it was supposed to be long lasting,and organic,earth friendly.The biggest drawback of dexcool-it attacked the plastic and rubber gaskets,and even some GM head gaskets,from Cadillac on down.
 
#11 ·
My suggestion, and I am doing this to my wife's 2003 Astro AWD. Drain the radiator, take a gallon jug add 1 cup of cascade dish washer powder fill with warm semi hot water. sake it till the powder is mixed in the water add to the radiator fill with water. start the engine let it run for approx 40 minutes with heat on hi if you have rear heat turn that on too. Shut her down and let her cool. drain it again including the block etc. then I use a T in the 3/4 inch hose to attach a water hose. Open the petcock on the radiator and if there is on on the block open that too. turn the hose on start the engine turn the heater/s on again and let it flush. Shut it down again drain as much as possible then close it and refill it with coolant/water mix. This is an old truckers trick to clean the coolant system. I have done it many times over the years and never had a problem. It will clean sludge, oil, rust pretty much anything.
 
#12 ·
Thanks for all the suggestions. Today I completely flushed the entire system 7 times. Removing all hoses including the ones on the heating matrix and forced water through them. I even disassembled the overflow and scrub the inside of it. I did use a couple jugs of radiator flush (forget the name) and flushed the system multiple times. Took me about 10 hours all together between running the vehicle and cleaning. The coolant was almost black when I first started and then when I finished it was almost clear. Not perfectly clear but I figured I would run it for a couple thousand miles and flush again. I also replaced the radiator cap. I was going to replace the thermostat but honestly couldn't break the bolts loose. Next time I flush I will replace it as I did already buy one. I finally have front and rear heat and it hasn't come close to overheating. Maybe someone already replaced the LIM gasket because I don't believe that was the issue at all. I believe it was blockage from the rust or whatever the build up was. So far so good and I owe it all to you guys for helping me out. I was about to ditch her because I was frustrated. Thanks for all the help !
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top