Ok, this is going to be kind of long, but I'll try to be as clear as I can.

I've had my '92 Z28 for about 2 weeks now, and I've noticed that it's ran pretty hot from time to time since I've had it. If I'm on a country road doing 55-60 it's fine, but when I'm in the city it gets pretty hot. Some times it's right around the red or even into the red a bit.

The other day I let it idle in my drive way to see at what temp the fans kicked on. It got up towards the red and neither one kicked on. So I figured that it must be a fan issue.

My friend's dad owns a dealership so I took it into him and told him that the car was running hot and the fans weren't kicking on. I also told him that I wasn't sure if the thermostat was sticking either and to check that out.

He called back later on in the day and said that he went ahead and changed the thermostat, but he didn't think that my temp guage was working. He said that he hooked a temp reader up to the car and it said that it wasn't getting any hotter than 205-210 while the guage in my car was reading at 240+, so he said that the car wasn't overheating and that the guage just wasn't reading the temp accurately. I asked him if the fans kicked on for him and he said that they did.

Now, on the way home which is about 20 miles away the temp guage was normal on the highway, but once I got into town it started heating up again. It even got into the red a few times. Each time it did I pulled over, shut the car off, and popped the hood. I looked at the coolant resivour (sp?) and it wasn't boiling and it was right in between the fill cold and fill hot line, so I really don't think that the car was overheating. Am I right to assume that? I had an '87 camaro that overheated on me 3 times and each time it got into the red the antifreeze boiled over and steamed like crazy. I know he said that the guage wasn't working properly and that very well could be the case on a 14 year old car, but it really freaks me out when it reaches the red zone like that. I was thinking about getting an aftermarket temp guage at autozone and having it installed. Does this sound like the thing to do? Has anyone else had this problem? I just don't want to take a chance and screw the engine up.

 

I know I have a small electrical gemlin in my dash some where, my gas gauge dont work, and myoil Pressure works 1/2 the time. I definately would get a aftermarket gauge. definately want to be able to see what is going on. Plus that way you have a better guage that you know is accurate, unlike the factory ones.

 

I would try to research how the temp guage works, where it gets its signal from. I wish I could help more but I don't know how that guage works. If it does get signal from the CTS, then I would be worried about the CTS being bad because the readings from that sensor affect more than just that guage, I know the ECM uses that input for alot of operations of the engine. The CTS sensor is located on the TPI Intake Base Manifold on the front right under the throttlebody. The sensor goes into the manifold itself. Maybe even try re-seat the plug or clean it out with electronics cleaner.

 

Do you know of any good aftermarket temp gauges? I've been looking around on the net and all I can find are water temp gauges....

 

If the CTS was bad would i get a "service engine soon" light?

 

water temp is what you want. I would suggest good old Autometer. I have never had issues with themin the past. generally when I get a new toy car like my camaro, one of the first things I try to get in is a autometer water temp, oil temp, oil pressure. I have found that factory gauges are not that accuralte.

 

temp gauge gets its signal from the coolant temp sending unit which is between the #1 and #3 plugs on the driver cylinder head, it has a single 16 gauge GREEN Wire going to it, they are known to go bad.