gigatigga

Hi i just bought a 1992 g20 conversion van. only 110k miles, 5.7l v8 (as far as the vin tells me), the outside is rusty and rough but the inside is really nice, only paid 850 bucks for it.

Anyway, its doing this thing where it will take maybe 10 minutes of driving to move from 100 on the temp gauge then it climbs really quickly to the red zone. I got out the first time it got to the red zone and the radiator hose on the right was dead cold. It wasn't smoking or anything, my heat does work, so i was lead to diagnosing this as a stuck closed thermostat.

I got some estimates on replacing it because i'm not that mechanically inclined, and i've been told because i have AC on mine that its a lot of work to get the thing out and replace it. But then i keep having people tell me i'm crazy to have a shop replace something like a thermostat for 250 bucks.

I have tried searching online but it appears that info on these vans is pretty sparse on the internets. Does anyone with any experience with these vans know if the 5.7l motor requires you to take off the AC compressor to get to the thermostat? Maybe its not the thermostat at all?

I'm open to any suggestions, please help!

Thanks a bunch
Rob.

canucklehead

The thermostat is on the front of the engine. Just follow the upper rad hose to the engine and where the hose clamps onto the the thermostat cover. Its a 10 dollar part, and is easy to do.
My advice is to go buy a haynes repair manual. You may as well familiarize yourself on how to do these little repairs. Its a good way to save $. If the upper rad hose is cold and the engine is hot, then yes replace the thermostat....and no, you do not have to remove any ac parts to do it.

greenfire

Might be time for a new radiator if the thermostat doesn't fix the problem. I went through the exact same scenario on my 92 G30.

canucklehead

True. Those vans can be re-cored unlike the newer all aluminum/plastic rads.
If you have the rad out, do the water pump at the same time.
I would at the least flush the cooling system to make sure there is no obstructions.

greenfire

I should of kept quiet. Guess what blew on my 99 G van today! The radiator!

Looks like a complicated job for DIY. Its a 3500 so it has the oil cooler lines and everything.

gigatigga

Well thanks everyone for the tips, i took a look and maybe i can do it myself, but i found a shop to do it for 150, think i might just do that as opposed to risking breaking something else. I hope this is all it needs to get going, hoping it makes a pretty decent tent replacement for some summer camping!

canucklehead

Don't sweat it. Its not that hard.
I shopeed around and got a new rad for mine for 330 bucks Canadian. They are not cheap.
The hardest part was getting thos little round plastic covers to snap over the connectors on the oil cooler lines....
I would do your water pump and the thermostat at the same time too.....
Also check your serp belt tensioners....