While driving to work this morning I noticed the air out of the vents was blowing ice cold even though I had the heat on full blast and had driven about 10 miles. Next thing I know the car was running like crap and the high engine temp light flashed on. I pulled off and turned the car off immediately. I let it sit for about 10 min with the heat on...which eventually got warm and started the car. The car was then at normal operating temp and drove and ran fine.

I was thinking the thermostat. What do you guys think? If so couple questions...

1. Where is it located on the car?
2. How hard to change?(Ive changed a couple on other cars)
3. Do you guys think I did any engine damage for that 15 sec that the car was super hot?

Thanks

 

What year and engine is your car?

If its a 3800, the thermostat is right on top, and super easy to change. You will see a radiator hose going to the engine on the top right hand side.

If its a newer 3.5L/ 3.9L, the thermostat is on the passenger side, just to the right of the serp-belt (when looking at the engine with the hood open) and its all the way at the bottom. This thermostat is also pretty easy to change.

If you have a different engine, I am not 100% sure where the thermostat is on them, but they are probably in similar locations.

BTW, I doubt in those few seconds you did any engine damage, as long as you turned the car off as soon as it over heated, you should be ok.

 

What kind of MC? If it is the 3.4, it sits right on top of the water pump housing(passenger side,front) Just replaced the water pump on mine,sits right there.

If it was blowing cold air with the heat on, typically this means that you are low on coolant. With the engine cool, check your coolant level in the radiator and the over flow tank. Fill with 50/50 mix as needed.

I doubt running it hot for 15 seconds did damage, but you never know. The big question is where is the coolant going if low. Mine never overheated, but was leaking coolant and the culprit was the water pump. Replaced the water pump,serpentine belt(both easy as hell on the 3.4l) and changed the coolant. After refilling coolant, run it for a day or 2, keeping a close eye on the level in the radiator/overflow. Carry extra coolant with you just in case you're out and about and it's low. If the level drops again, bring it in to be pressure tested. Costs abou $30. That will tell you where the coolant is leaking from. Could be a number of things, most expensive probably being the Lower intake manifold gaskets.

Hope this helps. Good luck!

 

We need more information about your car.

Also check if you have air in the system if your coolant levels are fine. Just start the car, and unscrew the bleeder valve on the thermostat housing until liquid comes out in a stream.

 

sorry its a 2000 monte carlo LS so i belive 3.4 ltr.

I did have the lower intake gaskets replaced about 40k miles ago and the car now has 126,000 miles. The car intermittantly flashes a low coolant light but only after I go over bumps, etc but then shuts right off. I havent checked the coolant in the last couple weeks but when I did last it was fine.

I also replaced the water pump about 40k miles ago also.

I thought it would be the thermostat if it was sticking and not allowing the coolant to circulate. Otherwise what would explain the car running fine all day yesterday and after today?

Thanks

 

Check your coolant, both the overflow tank and the radiator. If the levels are good then try bleeding your system. Maybe some air is getting in? If it bleeds fine then I would check your thermostat.

The housing is easy to find, just follow the hoses. After you put the thermostat in, you'll probably have to top off your fluid, then bleed again.

 

.....also so if its a 3.4 liter is the thermostat still on the passenger side by the water pump? Also how many bleed valves on the car and where? Like I said Ive done this before on other cars but just dont the engine of this car to well, thanks.

 

On the 3.4 liter its on the drivers side by the crossover pipe. The housing is slotted for the back bolt so all you need the do is loosen it a few turns and remove the front bolt completely and it should slide out.

 

I just looked at my 3.4. I was mistaken. The thermostat appears to be driver side, under the Throttle body assembly. Follow hose from drivers side of radiator to top of engine(past 1 of 2-that I know of-bleeder screws) You'll see the typical thermo housing if you follow the pipe, that the bleeder screw is on, down to the motor. The other bleeder screw is right on top of the water pump, sits on top of a black pipe. You can't miss it(well, I suppose you could ) Thermostat looks like a minor PITA but not too bad. I took this opportunity to check my coolant level. Still holding-Yay!

 

the thermistat cold be stickin open not allowing the motor to operate ok and stuck shut temerarly when the light came on. my sugestion is replace it and bleed the sestem for air and go from there.the thermostat is pretty cheap but it can cause alot of damege when it gets stuck shut.