Car gettin Hot!!!

I have a 97 Pontiac Grand Prix 3.8 Non-Supercharged that just hit 70,000 miles. Ever since I put that little modification from e-bay in (the resistor at the end of the air intake air senser) and put a Thrasher CAI in the car has been heating up really bad. Temp will get around 210-240F when I'm sitting at a traffic light. The GM dealer gave me some nonsense that it was supposed to get up that hot, it's freakin' burning the top of my oil dipstick. Anyway, I changed the thermostat and flushed the cooling system, which didn't help one bit. I was thinking of replacing the water pump, but it's not leaking or making any noise. The fans are working on low and high when the AC kicks on.... So I really don't know what to do and it's getting hot here in the desert. If anybody has any idea's, PLEASE let me know. Thanks!

Put a 160 degree tstat in and take that resistor out.

Put a 160 degree tstat in and take that resistor out.


I agree with Ripn12s suggestion as a starting point. Another suggestion would be to make sure the radiator has sufficient airflow and none of the internal lines or passages are blocked. We had a guy a few weeks ago with a similar problem located in the desert Mexicali/Calexico, CA.

He flushed the cooling system and bled properly. Changed the thermostat and still had high temperature at idle.

He found 5 internal lines within the radiator clogged possibly due to old Dexcool sludge. Just my 2 cents. :2cents: Good luck!


http://i5.photobucket.com/albums/y186/lizzywiz/gtp.jpg
Thrasher CAI, DHP v1.0 ECU,
3.25 SC pulley, CAIT GMAF, Hi-Flow CAT,
u-bend delete, 160 TS,TB spacer,
MSD 8.5mm wires, Autolite 104 spark plugs,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials

The resister was takin out a while ago because I thought that was the problem. That T-stat sounds like a good idea. I actually called around a little to find it and no one carries it, looks like an online part only.

I just flushed the radiator too with prestone cleaner and it seems like all the tubes are clean but I couldn't really tell.

Also, I put that Thrasher CAI in and I saw another post where this guy had the exact same setup and his car was doing the exact same thing.

Thanks peeps, I'll try it out and let you know

The resister was takin out a while ago because I thought that was the problem. That T-stat sounds like a good idea. I actually called around a little to find it and no one carries it, looks like an online part only.

I just flushed the radiator too with prestone cleaner and it seems like all the tubes are clean but I couldn't really tell.

Also, I put that Thrasher CAI in and I saw another post where this guy had the exact same setup and his car was doing the exact same thing.

Thanks peeps, I'll try it out and let you know

There is no way the CAI is the trouble. Pull Tstat. I run a Thrasher and a 160 Tstat. My temp never goes above 170. And I live in Florida, with a couple mods.
Have you tried running it (while sitting in your driveway) with the cap off and see if the water is moving?
Let us know.

There is no way the CAI is the trouble. Pull Tstat. I run a Thrasher and a 160 Tstat. My temp never goes above 170. And I live in Florida, with a couple mods.
Have you tried running it (while sitting in your driveway) with the cap off and see if the water is moving?
Let us know.


Just my 2 cents. :2cents: Jim, I agree with you but I've heard of a similar problem with CAIs not just Thrasher in which I believe is the ECU modifying the fuel injector pulse width for a lean condition which may cause the engine to heat up. Mainly on stock GTs and GTPs. The effect is seen when the engine is fully warmed up and the ECU is operating in closed and open loop mode operation. Plus we have to realize that he has a stock ECU and the fans kick-in on ours at a different temperature, etc. Our DHP ECUs are programmed specifically for CAI operation.

It's possible that the bogus resistor mod damaged the IAT sensor or there is a connection problem.

The IAT sensor in conjunction with the MAF sensor and ECU helps control the air/fuel mixture being burned in combustion. The IAT sensor is calibrated for temperatures vs. resistance, given a temperature of the inlet air, the sensor gives a certain resistance that is read by the ECU. The ECU takes that resistance and then makes decisions, based on the fuel map, and sends the correct voltage pulse to the injectors to inject the right amount of fuel into the cylinders. If the temperature of the inlet air decreases, the IAT resistance increases, and vice versa.

One thing this guy can do is have the ECU/PCM reset and force it into re-learn mode and then monitor the engine temperature after full warm up and see if there is any change.

Its worth a try and if it makes no difference then he should go with the thermostat suggestion or have the radiator pressure cleaned by a professional. Plus as you suggested it doesn't hurt to make sure the water pump is working properly. As a last resort he might consider going to a DHP ECU.


http://i5.photobucket.com/albums/y186/lizzywiz/gtp.jpg
Thrasher CAI, DHP v1.0 ECU,
3.25 SC pulley, CAIT GMAF, Hi-Flow CAT,
u-bend delete, 160 TS,TB spacer,
MSD 8.5mm wires, Autolite 104 spark plugs,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials

also need to realize that 210 is right around the normal operationg temps

also need to realize that 210 is right around the normal operationg temps

I agree Rip, however, he's getting up as high as 240. 210 is normal because GM engineers want the car to run that high for emissions purposes. I have 3 GM "W" bodies (GTP, Regal GS and Regal LS) and none ever come close to 210 and I'm in the desert with temperatures above 100 degrees. With the AC on, the temp indication decreases and on average reads approx. 190 or less during long idling.

Hopefully, he figures it out.



http://i5.photobucket.com/albums/y186/lizzywiz/gtp.jpg
Thrasher CAI, DHP v1.0 ECU,
3.25 SC pulley, CAIT GMAF, Hi-Flow CAT,
u-bend delete, 160 TS,TB spacer,
MSD 8.5mm wires, Autolite 104 spark plugs,
Goodyear Gatorback Serp. & SC Belt,
Nitto NT555R Drag Radials

Guys, I've checked the water pump to make sure it's flowing and it's really kicking the water around. I'm going to try resetting the PCM because I think your right on that resister maybe reprogramming the unit. I ordered that 160 thermostat and I'll let you know how it turns out. I think your right bnaylor3400 with the mix being richened up. So I'll test it out and let you know the results. Thanks a Bunch!!!