Ok, I installed a Tstat on my 97 GP Gtp, 195 degree... now, on my temp guage (I live in Detroit and now the temps are 30-40 degrees) the car warms up faster now that I've replaced the t stat, but I'm still concerned that the temp guage needle is just above 1/4 of the temp guage, before I, replaced the tstat it would be just below 1/4 of the gauge, I would at least like the temp needle to be halfway of the guage... is there a specific reason why the car is running cooler? Or is it just normal?
Temperature, T-stat, Operating Temp
- Thread starter villanex
- Start date
Chadgervais
Former GP Owner
I believe the scale on your car is 160....210....260.
The quarter mark would be 185. Perhaps your old stat was 180? That would put your needle just below the quarter mark. A 195 stat would put you just above the quarter mark.
This is completely normal. Its not running cold, the gauge just wants you to think that. For some reason GM wanted to be different with these cars and put the low mark at 160 instead of 100. My 2004 has a low mark of 140 so for me 195 is halfway between the quarter and the half. In traffic it rises to 220 (which is just over half) before the fans kick in and drop it back to 200.
The quarter mark would be 185. Perhaps your old stat was 180? That would put your needle just below the quarter mark. A 195 stat would put you just above the quarter mark.
This is completely normal. Its not running cold, the gauge just wants you to think that. For some reason GM wanted to be different with these cars and put the low mark at 160 instead of 100. My 2004 has a low mark of 140 so for me 195 is halfway between the quarter and the half. In traffic it rises to 220 (which is just over half) before the fans kick in and drop it back to 200.
looking at a pic I took, my gauge says for the lowest possible temp is 100, Mid is 210, and high being 260. My Fans come on just B4 reaching mid, and my last T stat was a 195, but it WAS stuck open.
Chadgervais
Former GP Owner
Hmm. Just a thought... there are some GPs of your era that have 160 as a low number on the gauge.
If your low number is 100 and mid is 210 then your quarter mark is 155. I dont know when, but sometime in the late 90s GM like many OEMs began using "dummy" gauges. They do not move in a linear fashion but are controlled by the computer. Think of it this way: if 100-210 is half of the range, then why is 210-260 also half of the range? 110 degrees gets you to half, then 50 gets you to HOT, doesnt make much sense.
Assume 155 is the quarter mark. If your stat was stuck open, given outside temps, its reasonable that youre engine would run between 150-160. I cant say for certain, but if the gauge is non-linear then the quarter mark could represent anything from 140-180.
If you have access to an OBD reader with temp functionality, you can chart what each line represents up to the point the fans come on. I use a bluetooth scanner and Torque on my smartphone. With a stock 195 stat, I run between 185 and 192 when im going faster than 35mph or so.
If your low number is 100 and mid is 210 then your quarter mark is 155. I dont know when, but sometime in the late 90s GM like many OEMs began using "dummy" gauges. They do not move in a linear fashion but are controlled by the computer. Think of it this way: if 100-210 is half of the range, then why is 210-260 also half of the range? 110 degrees gets you to half, then 50 gets you to HOT, doesnt make much sense.
Assume 155 is the quarter mark. If your stat was stuck open, given outside temps, its reasonable that youre engine would run between 150-160. I cant say for certain, but if the gauge is non-linear then the quarter mark could represent anything from 140-180.
If you have access to an OBD reader with temp functionality, you can chart what each line represents up to the point the fans come on. I use a bluetooth scanner and Torque on my smartphone. With a stock 195 stat, I run between 185 and 192 when im going faster than 35mph or so.
97 temp gauges all started at 100.... To the OP I too have a 97 and never realized how far off that gauge was till I got my AF...
Chadgervais
Former GP Owner
why did GM feel the need to screw with the gauges like that? Some start at 100, others 140 and others at 160. Also, when did GM change the HOT line from 280 to 260? Some Oldsmobiles go 100...200...280. Ive seen Camaro's go 100...220...280.