2003 Century thermostat

[trafman71]

A couple days ago, the temperature gauge on my 2003 Buick Century 3.1 started moving erratically where it would go nearly to the red, then suddenly go back down. Today, I've noticed that along with the gauge's erratic movement that the heater is not getting warm. I was thinking it may be the thermostat, however, what is sad is that I cannot locate the thermostat on this car. I'm not too experienced with these things, but I always thought the thermostat was where the radiator hose bolted onto the engine, but I cannot find a thermostat anywhere in that vicinity. Can someone advise where I may locate the thermostat so that I may check to see if this is indeed the issue? Any help would be appreciated. Thanks.

[Dan 37]

Sounds like a classic case of low coolant level

[Lefty22]

I agree with Dan, Sounds like coolant level is low. check coolant level and check for leaks.

[chrisj]

If the fluid is low, you have to bleed air from the system. Most 3.1s have two bleeders, one on each side of the engine. One is near the coolant pump, the other near the upper hose outlet. Hope this helps.

[Dan]

yes, check the coolant level, if you add you need to open the bleeders BEFORE you start to fill it.....make sure the motor is cold when you do this. also look real hard at both sides of the intake (front and rear) for leaks, it's common.

[rustyroger]

I agree with the other guys-sounds like low coolant level.One thing I`d like to add, why is the level low?.Modern motors dont normally leak fluids like they used to.I think it would pay big dividends to check out the root of the problem rather than just treat the symptoms.Remember, "Do it nice or do it twice!". regards , rustyroger.

[trafman71]

Thanks to all of you who responded to my plea for help. My cousin and I appear to have it. We did actually find that the thermostat was stuck, so we replaced it. We did bleed using the bleeder valve while adding some new coolant. It seems that since the thermostat replacement that it is taking longer than usual for the thermostat to finally open up, but it does finally do so after lightly revving the engine a couple times (appears that it won't do so by simply idleing). I hear the coolant "gurgelling" more than before, but the engine is not overheating.

If anyone can tell me how I might reduce the gurgelling or what may be the cause of having to rev the engine before the thermostat decides to open, that would be great. Thanks again for all of your help and insight!

[rustyroger]

I came across a similar problem years ago when I worked as a mechanic, we had several datsun owners complaining of overheating and noisy cooling systems.It took a bit of tracking down but we found the water pump impeller had eroded and was not circulating the coolant effectively. This would be consistent with having to speed up the engine to open the 'stat - you are in effect speeding up the water pump. One thing we did notice was that with a new pump fitted on startup ther was a sloshing noise for a few seconds as the heater was purged. Hope this helps,regards Rustyroger

[guyopel]

Sounds like you still have air in your cooling sys.
You need to look at your intake manifold gaskets for leaking coolant ( a recall for the 3.1 ) as a place you may be loosing coolant . HTH