Chevy Astro 4.3 v6 question please?

Question

What are some symptoms of the thermostat being stuck open? Last fall while it was still warm, the temp slowly climbed to 230F then settled back to its normal operating temp. it now operates within temp on the gauge, but i get no real strong heat like a GM should be providing. I suspect the stat is stuck open after having been stuck closed and if this is the case, do I replace it since im good with my wrenches and sockets, or do i not want to fool with it and have a garage do the work?

Thanks ahead of time as always.

to clarify what i said before, what i meant was that in my experience, GM cars have been noted for VERY good heat because of its liquid-core design. european cars have electric heat and it SUUUUCKS!

Answer 1

If the car reaches normal operating temp in a short amount of time..say 15 minutes of driving, then the stat is ok. Sounds like the problem might be the temperature control door actuator. Run engine til normal operating temp is reached and turn heater controls to high hot with high blower. Locate your heater hoses that run from the engine to the firewall. Feel the hoses. One should be hotter than the other. If so, the problem is inside the heater box. Most likely a bad temp control door actuator or the controls. If both are only warm, then you have a restricted heater core or hoses.

Answer 2

yes, I think you should replace the thermostat. It's not that hard. I would recommend that you use an oem replacement from the dealer though. It might be a few dollars more, but chances are you won't have to replace it again. I've had to replace aftermarket t-stats several times to get one that worked properly. Make sure you get all of the air purged out of the cooling system and top off the resevoir with a little extra past the full hot mark. If there is any air trapped in it, after it cools off, it will draw in the extra coolant from the resevoir after it burps the air out after cooling off. If you get a thermostat that has extreme gauge fluctuation, you can drill a couple of small 1/16" holes in the t-stat flange. This helps with the gauge fluctuation by allowing some constant coolant flow through the t-stat. There was a gm bulletin discussing this years ago.

Answer 3

Usually when the t-stat is stuck upen, the car would tend to run cooler than usual...and take a longer time to get up to temps. Low heat could also be an indication of a blockage in the heater core, pretty common if you have not had your cooling system flushed regularly and are using GM Dexcool antifreeze (the red stuff).
The t-stat should be pretty straight forward, drain coolant, remove the upper radiator hose and t-stat housing, pull out old t-stat, clean any old gasket material off housing and intake, install a new t-stat and gasket and replace the housing and upper hose. fill system with fresh coolant. Be careful with the housing bolts, they might be stuck in the manifold, don't be a gorilla when taking them out, if they seem not to want to loosen, go see a professional, better to let them do it then to have to pay to have broken bolts drilled out of your intake.

Answer 4

If the engine temp is normal but you still are not getting normal heat, you either have a bad heater valve, stuck blend door in the heater box, or air pocket in the heater core.
And to avoid major disappointments, I suggest you don't look at things like "GM should be providing". There is no such thing, and if it indeed does provide anything consider it your major luck that may not last long.

Answer 5

Replace the t-stat. It is cheap insurance against overheating. If the bolts appear to get tighter as you try to back them out, turn them in again and use lots of WD-40 on the threads. Work the bolts in and out until they come out fairly easily. Just a little tip, I have twisted off t-stat bolts in the past.

Answer 6

Errr...I think you better leave the repairs to someone that knows SOMETHING about cars, dude. Every European vehicle I have ever seen has a liquid type heating system.

Answer 7

Your coolant is low.

That's all.......