overheating/ thermostat change

[Chris H]

My 1991 ZR1 has 75000 miles on it. It gets very hot in traffic (around 200) I know the original thermostat is 180. Im thinking I may need to change it. Has anyone else had this problem and have and suggestions on what type of thermo i should get. Also if i do need to change the thermostat can someone please give me detailed instructions on how to do so. (i hate to admit it but im an amateur mechanic and i dont want to screw anything up) Im about to take the car to floida and DO NOT want to ruin it in that heat

[Kevin]

have you ever pulled/cleaned the rad? do you have the stock chip?

[Chris H]

kevin I just made another post requesting info on how to pull the radiator. I would love to know how and I will absolutely try it. Also, I do have the stock chip. I have also considered wiring the car to have the fans on all the time (FL car) any thoughts and instructions on radiator removal and cleaning would be wonderful

[ZR1North]

Sent you a PM Chris. I have a write-up that will definately help.

Bob

[Chris H]

Thanks Bob I replied to you and am looking forward to your write up.

[Kevin]

getting a new chip would probably help. contact mark haibeck @ http://www.zr1specialist.com/

[A26B]

Originally Posted by Chris H

My 1991 ZR1 has 75000 miles on it. It gets very hot in traffic (around 200) I know the original thermostat is 180. Im thinking I may need to change it. Has anyone else had this problem and have and suggestions on what type of thermo i should get. Also if i do need to change the thermostat can someone please give me detailed instructions on how to do so. (i hate to admit it but im an amateur mechanic and i dont want to screw anything up) Im about to take the car to floida and DO NOT want to ruin it in that heat

You are correct, the original t-stat is 180F. However, that is where it begins to open. It operates fully open in the 105~200F range. 200F is NOT "very hot". In fact, I would say you are doing better than most if you are only showing 200F in traffic on a warm day. 225~230F is more common. Turn the AC off when you are in slow, stop & go traffic if it gets to that range.

I don't think anything is wrong with your t-stat. Virtually all cooling problems are due to accumulation of debris in the front of the radiator. You can't see all of it and it can't be cleaned properly in the car. Radiators needs to be removed for proper cleaning and even then it's a PITA to get all the little crap out of the core.

Low temp t-stats won't make an engine run cooler unless ambient conditions, air flow and radiator heat transfer capability allows.

You can check the cooling fan operation by letting the engine idle until the temp reaches 225F. Fans should come on. A manual fan switch or reprogramming the prom, as others have suggested is a good idea.

[Chris H]

thanks for all the replies. very much appreciated

Let me add this little nugget.

You bought the car used. You have no idea of the condition of any fluids or when they were changed last. Things to look at, oil, coolant, trans fluid, brake fluid and last diff fluid (this crap seems to last forever, must be the smell that keeps it good). At minimum at least check the coolant.

Once again the gauge on the dash is not linear or very accurate. You're guessing at 200.

It's never a bad idea to look things over and inspect them. Pulling the rad gives you a chance to check your hose condition, rad for for leaks or possible problem spots, clean the rad and gives you areal good opportunity to learn on a relatively simple project.

[Chris H]

Jeff,
Thanks for the input. I have infact done oil diff plugs and wires (plugs ahhhhh) The coolant will be checked during this project and I am also replacing the brake pads. Sorry to get off topic but what is the brake pad of choice (I drive 90% of the time on the street) What simple changes to the brakes will get me the most stopping power on a tight budget