Car takes forever to warm up

[helicopter23]

I have a 97 grand prix gt 3800 with 100k on it. This car takes forever to kick out hot air in the winter and cold air in the summer. The themostat never gets passed the 1/4 mark (cant remember actually temp), Whats wrong?

[Highbeamz]

I found my car would not get above 1/4 on the gauge in the winter either, even with a new thermostat. Take into consideration the size of the radiator...there's a lot of air flow to it and when it's -20C or colder....it's no wonder it takes a long time to warm up. Maybe there's an issue I don't know about...but my car gets hot in about 5-10 minutes if I'm driving it (not idling)...and considering all my driving is 80km/h+ on a freeway...

As for A/C, my cold only takes less than a minute to get cold.

How long is "forever"?

[tblake]

to the OP. Change the T-stat. If it has 100k on it with the original t-stat, its about time.

[helicopter23]

Originally Posted by Highbeamz

I found my car would not get above 1/4 on the gauge in the winter either, even with a new thermostat. Take into consideration the size of the radiator...there's a lot of air flow to it and when it's -20C or colder....it's no wonder it takes a long time to warm up. Maybe there's an issue I don't know about...but my car gets hot in about 5-10 minutes if I'm driving it (not idling)...and considering all my driving is 80km/h+ on a freeway...

As for A/C, my cold only takes less than a minute to get cold.

How long is "forever"?

The thermostat never gets above the 1/4 mark. In the winter car takes 5-6 minutes before thermostat starts to rise to the 1/4 mark and probally over 10 minutes to get to 1/4 mark.

In the summer it takes about 5 minutes to get to 1/4.

[Airjer_]

I'll third the t-stat. If it was a newer model it would have turned on the check engine light with a "insufficient coolant temp" code.

[Highbeamz]

I'll go with t-stat as well. I thought you were mainly referring to the heater temperatures, not the coolant temps. My last thermostat was stuck open (I assume anyway) because it would never get above 75*C (would not even hit the 1/4 mark) and took a long time to heat up in summer. Now with a new one my car his the 1/4 mark in no time in summer.

[BNaylor]

It sounds like there may be more than one issue. The engine warmup, operating temperature and A/C cooling issue are probably not related.

Remember the GP IP temperature gauge whether SE/GT/GTP has a different calibration and readout compared to other GM cars. The lowest reading starts at 160 degrees F and max is 260 degrees F. Mine reads around the 1/4 mark but obviously the actual engine temperature is above at least 160 degrees which is good enough not to trigger any DTCs and the engine does switch into closed loop mode of operation. But I have a 160 degree thermostat. Even on the low side my heater works fine considering the regulating temperature of a 160 degree thermostat. The '00 and under L36 and L67 models are still capable of generating a P0125 DTC if engine operating temperature was truly abnormal. This is the closed loop mode check. Only 2001 and up models can give the P0128 DTC in addition to P0125 which could point to a thermostat issue but normally that DTC will not trigger until it gets cold as far as weather is concerned.

To the OP are you the original owner? The reading could be normal if you have either a 160 or 180 degree thermostat installed. However, it probably won't hurt to replace the thermostat or get one rated at 195 degrees if this engine is stock. Also, just to be sure I would check the ECT sensor calibration just to make sure it is fairly accurate and providing the right signal to the PCM module. Another option is to run a scan with a full function odb-ii scan tool and see what the scanner sees for engine temperature.