2002 Buick Century Temp Problems

soulcrusher

I have a 2002 Buick Century Custom. I had the intake manifold gasket replaced a few weeks ago including the thermostat, and water pump. I replaced with new coolant and bled system. Engine now runs up past the 3/4 mark and then the fans kick on at idle. Once the fans kick on it cools to 1/4 then creeps up again to 3/4 and fans kick on and it will repeat this process. I notice that the car idle also drops down a little bit at the higher temp and I can hear a tap. If I press on gas the temp comes down. The top radiator hose is hot and has half to 3/4 pressure on it. Also noticing some coolant loss with no evidence of leak. Thank You in advance for any advice..

imidazol97

How does the heater operate? Hot at times and cooler at others?

I'm guessing low coolant level leaving some air in the system. When car is cool, remove the radiator cap and check the level. If not up to the cap, then prepare your mixture to fill it, start the engine with a helper present to hold the accelerator at about 1500-2000. This will compress the air in the system and the radiator level should drop. Fill it to full, replace the cap, then let the engine come back to idle. Then check level in the reservoir after the engine is fully warmed up.

Then open the bleeding screw on top of the thermostat housing to release any air trapped there.

Check level of reservoir each day until certain you don't have another leak.

ray80

Hhmm I am thinking it is likely 3.x engine and perhaps two bleed screws?

soulcrusher

Guys,
Thanks so much for taking the time to respond to this. Heat is working fine and system has been bled through both bleeder screws. It is the 3.1 motor. Is it possible with the temp fluctuation that the stat which was replaced could be defective?

imidazol97

soulcrusher said:

It is the 3.1 motor. Is it possible with the temp fluctuation that the stat which was replaced could be defective?

I'd siphon out enough antifreeze from the radiator cap to lower the level and remove the thermostat. I assume it is fitted into a large o-ring like the 3800's I'm used to. The edge of the thermostat should go into the slit in the middle of the o-ring. See if that's how it was installed. While there I'd replace it with a Stant SuperStat, I think they're called.

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