97 runs warm

[Girrer]

I have a 97 lumina with a 3.1. It runs normal ( needle in middle of gauge. 192 if I remember right). Until I stop or drive slow then it gets up to 226 when the cooling fans kick on. At this point it does cool down and I did not want to push it so I shut the car off. It has new upper and lower hoses, thermostat, temp sensor, fluid flush and radiator cap. I have checked to see if the radiator is plugged and it flows vey well. Did a compression test and compression is good. ( all 6 at 145-155). The water pump appears to be fine, but it is the only thing I can think of to try next. I want to get this taken care of before it gets really hot out, and don't really think it should be getting that hot just idling in 60 degree tempature. If anyone has any ideas or experience with this problem any advice would be appreciated.

[crumpd13]

Sounds like you have a good running cooling system if all the above has been replaced. If you have good circulation (both upper and lower hoses are the same temp) then u can rule out the pump. I would hook it up to a scanner and read the live data to see what the actual temperature reading is from your switch, and then measure the temp with a heat gun around the thermostat housing. I haven't had a lot of experience with the 3.1 but I question the switch.

[Girrer]

I just checked the thermostat housing with a temp gun, the sensor seems to be right, I got a lot of different readings the highest was 235. And this was after a forty minute drive and sitting in the driveway for about 5-10 minutes.

[crumpd13]

Typically when coolant temp sensors are bad the readings will bounce around dramatically on the live data. What temperature reading did you get from your heat gun?

[Girrer]

Anywhere between 150 and 235 I checked it probably 25-30 times. 185 on the hose from the thermostat

[crumpd13]

I'm not trying to run you in circles lol. But you could very well have a bad thermostat. You wouldn't be the first to have a new part go bad. I'm waiting for others to chime in to help you. I may be overlooking something. Again, sorry if I'm not much help

[j cAT]

Originally Posted by Girrer

Anywhere between 150 and 235 I checked it probably 25-30 times. 185 on the hose from the thermostat

like was mentioned the thermostat is most likely the problem. what happens is the thermostats do not fully open when the thermo temp is exceeded.. they then at low engine RPM do not pass the proper amount of coolant so @ 0MPH the temp continues to rise, fans come on ac OFF.....

then @90 MPH the engine temp is normal... very common lately with the chinese crap. you should buy a quality thermostat with a lifetime warranty and also test these before install see how much it opens ..

[Schurkey]

Originally Posted by Girrer

I have a 97 lumina with a 3.1. It runs normal ( needle in middle of gauge. 192 if I remember right). Until I stop or drive slow then it gets up to 226 when the cooling fans kick on.

Maybe this is just me. I don't understand where the problem is.

Car does not have an engine-driven fan. Low speed, or in park/neutral, there's little or no air flow through the radiator. Of course the temperature goes up eventually. (Maybe the key here is to describe HOW FAST the temp climbs from 190-ish to the point were the fan comes on.)

The sensor on the engine is calibrated to turn the primary fan on at something like 220 degrees. The fan comes on, the engine cools down.

Where's the problem? I think this is normal operation, especially in hot weather.

[j cAT]

Originally Posted by Schurkey

Maybe this is just me. I don't understand where the problem is.

Car does not have an engine-driven fan. Low speed, or in park/neutral, there's little or no air flow through the radiator. Of course the temperature goes up eventually. (Maybe the key here is to describe HOW FAST the temp climbs from 190-ish to the point were the fan comes on.)

The sensor on the engine is calibrated to turn the primary fan on at something like 220 degrees. The fan comes on, the engine cools down.

Where's the problem? I think this is normal operation, especially in hot weather.

he said @ 60 deg f in 5-10 min it when into fan mode parked in the driveway after a 45 min operation. that IMO would be not acceptable.

If the air temp was 90 deg f plus then I would accept the operation he has with the fans coming on that fast.
when it is 90 F plus the fan will be on all the time in traffic and parked.

I would expect this to take 20 min parked @60 deg f for the temp to get to 225-230 f for the fan to come on...