[fede]

Hey guys i just wanted to know something. Since the end of last winter i wasnt getting much heat. But winter was almost over and i just assumed it was the thermostat that was stuck open, so i was planning of just flushing the coolant and replacing the thermostat. Well i havent had a chance to do that this summer because i was busy working on other issues on my van. Now its starting to get cold so i need to do it. But i have a feeling that its not just the thermostat now. I think it might be the heater core as well. I reason why i dont think its the thermostat is because i just noticed today the the temperature gauge was climbing up to just under the yellow, and i still had absolutely no heat at all.(before the temperature gauge was low) Im a little confused at this point and wanted to know what you guys think. Is it the heater core as well or even something else?

Thanks!

 

[Jasen]

Better check that T stat and find why your engine temp is high. What year? As far as the heater, probably a bad vacuum control line. When the heat went out in my 97 it was because they routed the vac line right across the top of the motor to make sure it would be properly BBQ'd. Once I replaced the cracked, charred and burnt plastic line with some rubber vac hose and re routed it away from the motor, the heater worked fine.

 

[ghostrider1061]

i would lso flush the heater core to remove any crud that mite be in there. had a no heat situation with another vechile. flushed the core and got a lot of crud out. after that good heat. :2:

 

[Mr_Bowtie]

I would do a whole system flush and T-stat. Sounds like blockage somewhere. What speed was it almost overheating at?

 

[astro355]

I would do a whole system flush and T-stat. Sounds like blockage somewhere. What speed was it almost overheating at?

i would lso flush the heater core to remove any crud that mite be in there. had a no heat situation with another vechile. flushed the core and got a lot of crud out. after that good heat. :2:

Definitely a good idea.

 

[GaryZ]

With the engine warm, touch the heater hoses going into the heater core. If one is cold and the other barely warm, follow the heater hoses back to see if you have a bypass control valve (below the silver AC thingy). I found mine stuck closed, I sprayed WD40, manually worked the vacuum valve, and now I have heat.

By the way, I saw this fix somewhere on this forum . . .

 

[roferg69]

With the engine warm, touch the heater hoses going into the heater core. If one is cold and the other barely warm, follow the heater hoses back to see if you have a bypass control valve (below the silver AC thingy). I found mine stuck closed, I sprayed WD40, manually worked the vacuum valve, and now I have heat.

By the way, I saw this fix somewhere on this forum . . .

I actually just posted a bunch of photos and a diagram that show both this valve and the other one for rear heat over in this thread: http://www.astrosafari.com/viewtopic.php?f=34&t=4593

Just in case you wanted to see what this valve looks like...

 

[TimmyK]

With the engine warm, touch the heater hoses going into the heater core. If one is cold and the other barely warm, follow the heater hoses back to see if you have a bypass control valve (below the silver AC thingy). I found mine stuck closed, I sprayed WD40, manually worked the vacuum valve, and now I have heat.

By the way, I saw this fix somewhere on this forum . . .

I actually just posted a bunch of photos and a diagram that show both this valve and the other one for rear heat over in this thread: http://www.astrosafari.com/viewtopic.php?f=34&t=4593

Just in case you wanted to see what this valve looks like...

Thanks for the pics! I found my problem. The heater hoses going to the heater core were cold, even though the van was warm, and I had plenty of fluid. But I found a busted vacuum line going to the bypass control valve. I noticed that when I lost heat, the air conditioning seemed to stay on. And when I pulled out the heating adjustment panel I noticed the vacuum line going from the temperature selector and the air conditioning switch linked up. Which made sense. Going to fix tomorrow or Monday, if you don't hear back from me that was the problem.

 

[Mr_Bowtie]

Good work! The heater control valve is almost always the problem......its either not moving or leaking fluid. :lol: