OK heres what I have "95 z28 with 160 degree thermostat" When I bought this car last year it said that a new water pump was installed. So hopefully this is not the problem.

Heres whats happening. When I drive my car to work in the morning it is cool enough out that I dont run the A/C. Temperature seems to stay under the halfway mark. Oh and by the way my drive to work is long so it has plenty of time to heat up. Now on my way home with the A/C on, the temp goes up to just below the red line. Thats the highest ive ever seen it go. So I got worried and when I got home I poped the hood, and could hear the coolant boiling in the overflow and radiator. My coolant level is also where it should be, ive check it three days in a row. I also checked to make sure my fans were running and they are. Any ideas?

Thanx

 

If you look under the fron of the car does it have the plastic "air damn" on it.

It is about 1 inch thick 3-4 inces tall and is as wide as the car. Right behind the front bumper, it comes down below the bumper about 2-4 inches.

If you search im sure you could find a pic of it on here. Its called an air damn.

 

When the A/C is on, a greater load is placed on the motor and it will try to heat up. If you turn the A/C on when sitting at an idle, the fans should immediately come on. If they are not, this is a problem. My guess is they are working fine and your high temps are either normal, or caused by the 160* t-stat.

You should really have a 160* t-stat tune when installing a 160* t-stat. This can be done through a mail order tune, or with a Hypertech Power Programmer.

I had a 160* t-stat in my car for a while before I got a tune. I installed a manual fan switch so I could flip them on when the gauge reached the half way mark. After the MadZ28 tune, I haven't had to use the manual switch, and the temp never comes close to the half way mark anymore.

Thomas.

 

Here are aa few ideas that I have had.
I would be tempted to bleed the system (make sure it is well bled)


Also, what coolant are you running. I have seen several times the work of DexCool. Over time It tends to soilidify and block coolant passages, overheating follows. There is actually a lawsuit out against them. I have been running the green stuff (non-dexcool) for years in my Z28 No problems, very clean and no chunks forming.

 

got my 96 z this year on a trade for my truck, I found the car running warmer than I like, so I start looking and learning, found the ac coil about 40% loaded with trash, dirt.leaves, etc. removed top cover to find, cleaned the coils good, temp went way down, runs cooler with a/c on . new cap also.