I have a 1988 camaor Iroc-z 5.0(TPI) with a 5-speed tranny. My car overheats(engine temp goes up) when I am sitting in traffic for too long(about 10 minutes), but once I start moving a little more consistently the car cools down. It's not too big of a problem but if i want to go cruising or im stuck in traffic it causes a lot of trouble I have a fan but I have to turn it on manually with a switch. I leave this fan on as soon as I start the car. I drained and replaced the coolant, bought a new radiator cap, and replaced the top radiator hose. Im gonan replace the bottom one cause it looks pretty old. I think it might have an ADS thermostat. Please let me know if you have any info on my problem. THanks for your time.

 

Exactly how hot does it get? Keep in mind, the car is supposed to do that, to a degree, as there is no constant air flow over the radiator.

 

Yea, how hot is it getting? If it really is overheating, then I'd say hose off the front of the rad (bugs 'n $hit) to unplug it, so air can flow through it better,

If it still a problem, try changing to the next cooler thermostat.

 

It goes to 220 whille in stop and go traffic but will soon start raising until it starts to boil and i must pull over. It cant be an air to the radiator problem if it does not overheat while driving cause air goes through just fine and does not overheat while moving constantly.

 

Fan coolant switch, fan relay.

And cooling forum...

 

Check the bottom hose and make sure it is not collapsing.

Next it may be time to pull the radiator and have in checked out. Might be plugged. Or maybe just time for an aftermarket aluminum radiator.

You can also have a pressure test done to make sure you don't have a leak somewhere. Proper pressure on the system allows the coolant temp to go over 212* with out boiling.

Make sure your coolant is the proper 50/50 mixture. It is designed to have the best cooling properties with half water and half coolant. This will also help the coolant from boiling.

Other than that I would say check your fan and make sure it is pulling a good amount of air. If the motor is going out it may sound like its coming on but not operating at max rpm's.

Just out of curiosity, how are you tuned. Are you running a lot of advance on the timing. This can cause you to run a little hot. Certainly not to a boiling point. But it may be one small factor. Maybe back it off a little until the cooling problem is figured out.

 

OK, I had the same problem on my 92 RS. I had my fan hooked up to the switch and it got REAL hot while sitting in traffic, well over 225 and I was like HOLY SH*T! Anyways, I got to the point where I turned my fan switch on after it hit like 200 and when the temp dropped below 180 or i was on the freeway, Id turn it off. it Ran ALOT cooler then for some reason. Nayways, the fear was still there so I hooked it back up to the stock sensor. I also changed my Thrmostat. YOu may want to consider changing the thermo and picking up the Temp. Sensor for your block and hook your fan to it, as it kicks the fan on and off at certain degrees. Well worth the 20-40 bucks you spend, no worries bout that switch. Anyways just my 2 cents.

 

A stock z28 will rise to 228 Degrees before the fans kick on, this is for emissions resons. The car runs cleaner. Not a problem. But, you can get a fan switch that turns on at 200 and off at 180. Very effective.

 

I thought TPI cars had the primary fan set by the ECM as to coming on at 228º, and that the secondary fan is controlled by the fan switch at 252º, and/or A/C functioning.
Here's the link to what i've found:

https://www.thirdgen.org/techbb2/sho...hreadid=260999

 

i had the same problem as yout though i have an 88 iroc-z with the 350 and the coolant system was stock. i replaced the radiator to an aftermarket 3-core copper, 180 hypertech t-stat, jet 200on and 185 0ff fan switch. i thought the same though the primary was controlled by the ecm and it is but to a point. if the ecm senses the secondary fan coming on the primary is automatically grounded also. in case of failure of the primary fan kicking in at 220 the primary will kick on with the secondary at 240. so in essence the jet fan switch fools or tricks the computer. just another thought which has not been mentioned try a 2 fan set up with a primary and secondary and i believe the increased cfms of air will solve your problem as opposed to a single fan.

 

They may be controlled by different things but if you bypass them and connect them to eachother they will come on at the same time, and the car wouldn't know the difference. Mine was connected at the passanger side wheel well I couldn't tell you if yours is the same. But it does work I will see if I can get a picture of it on here so you can see what I'm talking about.