About 2 months ago I noticed that the temp would go up to 202F/204F then go back to normal about 182F at least that is what the scan guage reads.
Antifreez level is good does anybody think this could be a slow acting thermastat?
Would this be covered under warenty with 100K extended I'm at 49K now.


Scott

 

I don't think so. I have had a temp gauge on my B for almost a year now. I have the thermistor on the upper radiator hose, the temp is a little cooler there. Anyway, my guage usually read a little under 200F when the fan kicks in. I really don't think you have a problem.

 

That sounds normal considering the stat opens at or around 195 degrees. It's suppossed to cycle like that. No problems there for sure.

 

It just seems strange as all summer when it was hot the temp never went over 144F now it is colder it spikes up over 200 then goes back down and it stays there sometimes for an hour then sometimes it stays close to 200 the whole time.this has just started doing this for a year never went over 184F.


Scott

 

MY xB has been going up to @200 F for a little while, even when I drove with the scanner it did the same thing. The important thing is to hear the fan. I've got the same amount of miles on my B. Don't worry too much about it. Most thermostats don't open up until 185-190 degrees anyway, GM cars have a tendency to go to 220 before they open.

 

If you were running your A/C during the summer, the fan runs all the time with the A/C on. Without the A/C, the fan will come on by itself at around the 202 mark. the fan fan will stay on until the temp drops to approx. 185. Normal operation.

 

I have a ScanGuage2 and when my engine is warmed up it always reads about 182.

 

That's normal. Each temp sensor is not 100% accurate so they will not all read the same exact temp..

 

lol forgot about the A/C, I didn't even use it this summer. lol. And yes everyone should get different readings but in the same general area of 180F. Scan gauge gets the temp from the Thermistor on the engine block, you are seeing what the coputer is seeing. Anyone using a aftermarket gauge like myself will have slightly different readings due to where the temp sender (thermistor) is.

 

Mine normally reads 182-184. If I'm stopped in traffic, I've seen it go up in the 190s and I hear the fan kick in. I don't recall seeing it break 200, but I didn't have the scangauge in the summer. Guess it makes sense if it's reading the temp somewhere other than from the coolant.

 

it still reads the temp off the coolant, just depends where. lol I know that the most accurate tempurature is usually where the thermostat is or in the head. I know mine personally reads cooler cause when I took a laser tempurature sensor beam thingy the upper hose was always reading a few degrees cooler then the lower hose. I put it there for easy access. lol

 

Something may be off. If the temp never went over 144F last summer, the engine was never fully warmed up. And if it stays close to 200F now for any length of time, that should not happen either when stopped or moving.

On my 06 manual with 10K miles, the blue light goes off at 137F, and the ScanGuage usually shows 184F in normal driving whether around town or on the Interstate. If stopped in traffic or for a train, the temp will eventually rise to 202F and then the fan comes on until it reduces to the low 180s, and then it will cycle that way every few minutes until the car gets moving again.

 

its normal. my friend's 1994 Lumina Z34 (R.I.P) hovered around 210 215. its an all alluminum engene

 

The person with the problem said: "... all summer when it was hot the temp never went over 144F." And now he says the temp stays over 200F.
If we all say our xBs run at 184F, how can this person's xB be "normal" running at 144F in the heat of the summer, and over 200F in the winter?

 

I suppose there might be a problem but the car is not overheating. As far as the lumina goes. The normal running tempurature for GM cars is roughly around 220-240 depending on the model. The main thing is that we are not seeing numbers in the 280+F. If one does then that is overheating and that is a problem.

 

We know it was not overheating because the red temperature light did not come on. But the engine is not running at its proper temperature ~185F like all our other xBs, so there must be a problem.

 

Mine runs 182-192 (according to the AutoXray scanner I have). That is more reassuring than a GM car I've owned in the past (that one used to go up to 232!)

So, I would also agree that if your temp is not around 180's then something is out of spec. Maybe your thermostat opens at slightly higher temperature or it doesn't fully open at all. But it is most likely nothing to be too concerned about. If the car was about to overheat, the warning light will turn on. Then you can worry about it. Or you can start throwing parts at this "problem". Replacing thermostat first would probably make the most sense.

 

And in the summer, apparently, it was staying open. Better to replace the thermostat now at his convenience, than to wait for a "event" to happen. Running cold is merely bad for efficiency, but on the other end, by the time the red temp light comes on, the engine must be shut down immediately to avoid damage.

 

The 144F may have been the intake air temp in the summer??????

 

The coolant thermostat can't read intake air temperature.