SnowDrift Posted July 10, 2006 Report Share Posted July 10, 2006 '93 GP with a 3.1 engine New cooling system. When I'm sitting in town with the a/c off, this thing still gets way above 220 deg. on an 80 degree day. When I drive down the road, the needle on the gauge sits almost two marks below 220. I have an OEM t-stat in, as well. I've added Royal Purple, recently, to try to help this out. Does anyone have any other suggestions on what to check in regards to the overheat issue? Thanks, SnowDrift Quote Link to comment Share on other sites More sharing options...
jeremy Posted July 10, 2006 Report Share Posted July 10, 2006 to powertrain Quote Link to comment Share on other sites More sharing options...
Regal_GS_1989 Posted July 10, 2006 Report Share Posted July 10, 2006 If the engine has been overheated like that already, there could already be some serious damage done. I would start by bleeding the cooling system, and see if that works. Quote Link to comment Share on other sites More sharing options...
SigEpCutlass Posted July 10, 2006 Report Share Posted July 10, 2006 Make sure that the primary fan is running around 220-225*F. If the cooling fan is not working, it may be the reason why it's running that hot. Quote Link to comment Share on other sites More sharing options...
SnowDrift Posted July 10, 2006 Author Report Share Posted July 10, 2006 the system has been bled out. No air. The primary fan must come on. It's on regularly, now. I never heard it before the new radiator - this tells me the new rad. is working properly and hot coolant is getting into the cooling fins. What temp does the second fan come on? SnowDrift Quote Link to comment Share on other sites More sharing options...
cutlsp Posted July 10, 2006 Report Share Posted July 10, 2006 is there white smoke coming out of the tail pipes and do you have to refill your coolent every couple days? Did you get a new radiator cap? Have you pressure tested your cooling system? Quote Link to comment Share on other sites More sharing options...
SnowDrift Posted July 10, 2006 Author Report Share Posted July 10, 2006 No white smoke and coolant level remains constant. Oil doesn't get creamy and there's not moisture on the oil cap. No steam forms on a mirror with the oil cap off and the mirror over the hole. Upper radiator hose is not hard upon startup. Yes, it's a new OEM radiator cap. New radiator, water pump, both by-pass hoses, upper and lower radiator hoses. Quote Link to comment Share on other sites More sharing options...
SigEpCutlass Posted July 10, 2006 Report Share Posted July 10, 2006 the system has been bled out. No air. The primary fan must come on. It's on regularly, now. I never heard it before the new radiator - this tells me the new rad. is working properly and hot coolant is getting into the cooling fins. What temp does the second fan come on? SnowDrift IIRC, the "primary" fan is on the passenger side. That fan is the main cooling fan and comes on at ~ 220-225*F. The driver side fan is hooked to your A/C, so that's the only time that will come on. Quote Link to comment Share on other sites More sharing options...
SnowDrift Posted July 10, 2006 Author Report Share Posted July 10, 2006 well, if that's the case, then it makes perfect sense why it always seemed to run cooler with the A/C on before I replaced all this stuff than when it was off. I never would have guessed it, though. I'm new to electric fans, though. Quote Link to comment Share on other sites More sharing options...
95oldsVan Posted July 10, 2006 Report Share Posted July 10, 2006 Theres ways to get your secondary fan to come on the same time as the primary and increase your cooling efficiency and also help the condensor cool off better as well. I havent checked that mod for these cars yet but did it to my Corvettes electric fan.I spliced the back up secondary fan to come on same time as the main fan and it really did a great job with cooling the temps down quicker and the a/c felt colder.I just wired it to splice into the main fan relay.Worked great.Maybe some here has done it and can post it.It can be noiser though,with both fans running. You can also buy a toggle switch kit to wire into the other fan and run the switch into the car so you can manually control the secondary fan at will or whenever you feel the need to kick it on. Just other options...even around here its in the 90's this week with high humidity...makes cooling the car down even harder to do in traffic. Oh and be sure theres no trash or leaves piled up in between the radiator and condensor. Quote Link to comment Share on other sites More sharing options...
GP1138 Posted July 10, 2006 Report Share Posted July 10, 2006 Do remember that the coolant gauge may not be accurate. Quote Link to comment Share on other sites More sharing options...
mfewtrail Posted July 11, 2006 Report Share Posted July 11, 2006 Is the water pump an OEM part or from a parts store? Just curious, because I've had bad luck with the cheap aftermarket pumps. Also, is your belt tensioner in good shape? Quote Link to comment Share on other sites More sharing options...
turby Posted July 11, 2006 Report Share Posted July 11, 2006 Not sure if it's possible but did they somehow put the belt on wrong? You said you have an OEM t-stat. Is it new? Quote Link to comment Share on other sites More sharing options...
SnowDrift Posted July 11, 2006 Author Report Share Posted July 11, 2006 The water pump is a NAPA part. The t-stat is "new" in that it's only about a year old. I flushed the cooling system last year and replaced it when I did this. I realize the gauge may be off, but I really think it's fairly accurate, or at least gives me an accurate range of temps. It ran a consistent 220+ before the t-stat change. Once I changed it, the temp ran consistently under the line below 220. After I changed the radiator, it runs even cooler. Logically, these things all make sense that the temps are dropping. I'm just not sure why it's getting warm in town. The water pump impeller was identical to that of the one I removed from it. SnowDrift Quote Link to comment Share on other sites More sharing options...
SigEpCutlass Posted July 11, 2006 Report Share Posted July 11, 2006 The water pump is a NAPA part. The t-stat is "new" in that it's only about a year old. I flushed the cooling system last year and replaced it when I did this. I realize the gauge may be off, but I really think it's fairly accurate, or at least gives me an accurate range of temps. It ran a consistent 220+ before the t-stat change. Once I changed it, the temp ran consistently under the line below 220. After I changed the radiator, it runs even cooler. Logically, these things all make sense that the temps are dropping. I'm just not sure why it's getting warm in town. The water pump impeller was identical to that of the one I removed from it. SnowDrift Trust me man. Check your PRIMARY FAN! I'm willing to bet that the primary fan will not turn on at the appropriate temperature when you're at a stop or driving around town. The fans aren't the greatest and are prone to dying out. I have the exact same problem because I've been too busy to be able to replace the fan. I can't work on my car in the parking lot of my new apartment. I've gotta do that though now that summer's here. Quote Link to comment Share on other sites More sharing options...
SnowDrift Posted July 11, 2006 Author Report Share Posted July 11, 2006 I'll try to swap fans from side to side this weekend, or maybe tonight then turn on the A/C to see if it starts up. I know the driver side one works. Thanks Quote Link to comment Share on other sites More sharing options...
SigEpCutlass Posted July 11, 2006 Report Share Posted July 11, 2006 That might be a good way to test them I guess. Quote Link to comment Share on other sites More sharing options...
RJansen658 Posted July 12, 2006 Report Share Posted July 12, 2006 Ok... If the fan comes on, then it is not the fan.... the fan will not have a delayed reaction to feed. As someone stated above, your guage may not be correct, but to take that even further....there are two temp sensors on your vehicle. One that the guage inside uses, and one that the ECM uses to to sense when to turn on the fans. Maybe the guage inside is right, but the computer still thinks it doesnt need fans on yet. Sensors become "skewed" over time. any measuring type sensor with the exceptance of a potentiometer which degrades in a different way. Themosistors range will slowly get further and further from actual temp over time, for better or for worse so to speak. Extreme temperatures accelerate the process. Constant thermal cycling is the culprit though. A snap-on scanner is capable of seperate temp sesor monitoring in the graph mode I believe... Quote Link to comment Share on other sites More sharing options...
SnowDrift Posted July 12, 2006 Author Report Share Posted July 12, 2006 Swapped fans. Both are functioning fans. How about the relay that tells the fan to come on at a certain temp? If the CTS is bad, would I not have drivability problems since the computer would not be adjusting the fuel as the engine temp. changed? Quote Link to comment Share on other sites More sharing options...
SigEpCutlass Posted July 12, 2006 Report Share Posted July 12, 2006 The temp sensor under your hood could be bad if both fans work. The sensor malfunctioning in a way that is preventing the primary cooling fan from turning on at the temperature it should be, I assume. I'm not sure where to tell you to find it, as it's in a different location in my car. I can't even remember at the moment where that is. Quote Link to comment Share on other sites More sharing options...
RJansen658 Posted July 13, 2006 Report Share Posted July 13, 2006 The sensor can malufuntcion with no drivability issuses apparent. As I said, temp sensors like to "skew", which is basically where it will read a few degrees less or more than actual temp, thus causig it to run hot because the fans are coming on too late. Or the sensor for the guage may be "skewed" and reporting a higher than correct reading on the guage. A scan tool can easily answer all of your questions.... and actually... you may even be able to command the fans on with it. If you can command them on then it is definetly not a fan motor or relay problem, and that also greatly reduces the chance of it being an ECM porblem. I have seen several firebird ECM's that simply would never turn on the fan. Quote Link to comment Share on other sites More sharing options...
SnowDrift Posted July 13, 2006 Author Report Share Posted July 13, 2006 I'll try to get my hands on a scanner this weekend, then. Thanks Quote Link to comment Share on other sites More sharing options...
GIANT MOTH Posted July 18, 2006 Report Share Posted July 18, 2006 You know this same problem is happening to my 95 GP. The primary fan does not turn on. I've taken it in and apparently they fixed it but the fan does not turn on until the gauge hits red and sometimes just never turns on at all. Both fans are good. I've checked the CTP in the tstat housing for resistance and voltage and they check normal. The other sensor the CTS in the head. I have no idea how to test a one wire sensor and I have traced that wire going into the AC system (I think) through the firewall and back out to the ECM....but the wire diagram I'm using does not show this....it shows the tstat CTP (yellow/black wire) in the A/C circuit. . . . .my A/C is disconnected..............sooooooooooooo maybe I got a bad ECM. ??????????? Quote Link to comment Share on other sites More sharing options...
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