I just got a 180 thermostat(haven't installed it yet). Do I need to re-program my ECU in order to use it? Would a 160 thermostat make much difference?

No u wont have to reprogram the PCM.

Ive run both 180 and 160

no bad side affects besides maybe bad mileage

sorry for a stupid question, but what does a 180 thermostat do?

Stock is 195. That means that the coolant doesnt pass into the motor until the Tstat reaches 195 degs.

By using a colder tstat you keep the motor cooler.

Here is Texas I switched to the 160 becuase it gets pretty hot in traffic.

kewl then I guess 180 would do fine in vancouver canada.

makes sense i suppose. so 180 is the common mod? How difficult is it to install? If i can't do it myself, how much would it cost to have it done?

Very Easy to install

Should take maybe 10 min depending on what year GP u have

Here is how:
http://www.pfyc.com/supportfiles/tstat/tstat.htm

awesome, i appreciate the quick reply, though i do not have a gp yet :(

i have to sell my darn probe first... anyone interested?? :icon16:

Silly :D

i thought they made different tstat for the grand prix. like if u had a gt u would run the 180, and the gtp would run the 160. cuz they said the computer wont read it right or sumtin thing like, isnt that right?

Stock for both GT and GTP is 195.

Some cars will throw SES lights if the tstat is too cold.

Some people cannot run a 160 on their cars becuase they pull a SES light. I've had no problems with either tstat

Remember that at certain temps the cylinder walls have less friction due to the temp the block has.
That is why a car that has a too cold tstat the engine tends to last less.
195 is based on the OEM car setup the best temp to have the least cylinder friction. But if you modify the intake to reduce knock you need to cool the block and the intake flow. You will get worst mileage with a cooler tstat but a heck more power. SO depends on what you want from your car is the tstat that you install. And BTW I think that 180 would no SES any GP, 160 is another story

okay. cuz i had bought the 160 but wasnt sure if i should put it in or not. u think i should?

okay. cuz i had bought the 160 but wasnt sure if i should put it in or not. u think i should?

I'd say yes you should be fine with the 160....

I run the 160 in the summer
then the 180 in the winter

Correct me if I'm wrong here, but the stock PCM doesn't command the fans to turn on until 195. So if you install a 180 or 160 t-stat the car will stay cooler a little longer due to the stat opening earlier, but in stop and go traffic with no air flow the temp will still go to 195+ (in the staging lanes too). On the highway with windspeed to cool the rad...yea, then the temp will stay below 195.

At least that's how most of the GPs act unless they have a aftermarket PCM that turns the fans on earlier.

Correct me if I'm wrong here, but the stock PCM doesn't command the fans to turn on until 195. So if you install a 180 or 160 t-stat the car will stay cooler a little longer due to the stat opening earlier, but in stop and go traffic with no air flow the temp will still go to 195+ (in the staging lanes too). On the highway with windspeed to cool the rad...yea, then the temp will stay below 195.

At least that's how most of the GPs act unless they have a aftermarket PCM that turns the fans on earlier.

Yeah I can't wait for my DHP. The best I can do now to get the fans on early is use the AC.

my friend had a highly modded out 98 GT with a supercharger and he ran 180 in winter and 160 in summer and had no problems... this was in Michigan BTW if you live out west in LA or someplace where it is not seasonal... u should be able to get away with 160 all year...

Yeah I can't wait for my DHP. The best I can do now to get the fans on early is use the AC.

you have those numbers with stock pcm?? you're gonna be smoking with the DHP!

Correct me if I'm wrong here, but the stock PCM doesn't command the fans to turn on until 195.

195 is the thermostat and the fans dont kick on untill 215.

~Larry~

I've tried both, 160 and 180. Found MY car runs better with 180. And I think that is because someone asked once, "How is SHE running"? Now it has a mind of it's own.
http://img.photobucket.com/albums/v425/kustomkid54/1998PontiacGrandPrixGTP004.jpg

you have those numbers with stock pcm?? you're gonna be smoking with the DHP!


this thread is 8 months old!.....I believe those numbers include the DHP now....

PLEASE STOP BRINGING BACK DEAD THREADS....

sorry...