Overheating

[DTZ ZR1]

When in stop and go traffic coolant temp gets up to 250 degrees. Once I get moving it drops down to normal temps. I have changed the thermostat. I am thinking that it is the coolant temp sensor for the ECM. I figured that if it is that that I would also change the sensor for the gauage. Question is are they the same type of sensors and also am I on the right track with my troubleshooting? Thanks for any advice.

[XfireZ51]

When in stop and go traffic coolant temp gets up to 250 degrees. Once I get moving it drops down to normal temps. I have changed the thermostat. I am thinking that it is the coolant temp sensor for the ECM. I figured that if it is that that I would also change the sensor for the gauge. Question is are they the same type of sensors and also am I on the right track with my troubleshooting? Thanks for any advice.

You may want to put a scan tool on it and see if the gauge reading matches the CTS signal to the ECM

[Pete]

Do not drive it at those temps you could blow a head gasket,don't ask me how i know.

If she starts to get hot even in stoped traffic rev RPM's to about 2k she will cool down a bit,it will pump more water thru the motor.

I would check make sure both fans are working, also check/clean front of radiator

Pete

[Kb7tif]

Install a switch to turn on BOTH fans when you want, or burn a chip to turn fans on at 190.

[GOLDCYLON]

Its prob time for a radiator replacement. You might be able to remove it clear out all the leaves and debries and get all the sand and silt out from between the fins. But this would be my guess since I been down this road with 3 C4s already. A regualr GM replacement radiator solved the problem each time

[batchman]

When in stop and go traffic coolant temp gets up to 250 degrees. Once I get moving it drops down to normal temps.

Your radiator fan is not running. General suggestions that can help if you find yourself in this situation:

- turn on max a/c, most cars this forces fan on if it's operable

If that fails to drop temp within 30 sec or so,

- turn on max heat

This uses the heater core as a cooler. Yes the cabin will be unbearable but it will drop the engine temp.

Good luck,
- Jeff

[L8apex]

Here is what it is likely to look like when you pull the radiator shroud. I could not believe how much cooler my water and oil temps were once this was cleaned out!

http://img836.imageshack.us/img836/4723/rad2l.jpg (http://img836.imageshack.us/i/rad2l.jpg/)

http://img839.imageshack.us/img839/7379/rad3k.jpg (http://img839.imageshack.us/i/rad3k.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

[Hammer]

Just went through this. The left fan motor was not working. Runs fine now.

[rhipsher]

Here is what it is likely to look like when you pull the radiator shroud. I could not believe how much cooler my water and oil temps were once this was cleaned out!

http://img836.imageshack.us/img836/4723/rad2l.jpg (http://img836.imageshack.us/i/rad2l.jpg/)

http://img839.imageshack.us/img839/7379/rad3k.jpg (http://img839.imageshack.us/i/rad3k.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)I think I see Jimmy Hoffa's wallet in there.

[Coupe89]

Here is what it is likely to look like when you pull the radiator shroud. I could not believe how much cooler my water and oil temps were once this was cleaned out!

http://img836.imageshack.us/img836/4723/rad2l.jpg (http://img836.imageshack.us/i/rad2l.jpg/)

http://img839.imageshack.us/img839/7379/rad3k.jpg (http://img839.imageshack.us/i/rad3k.jpg/)

Uploaded with ImageShack.us (http://imageshack.us)

Thats what mine looked like yesterday Also has a skiddle wrapper and 3 to 4 plastic wrappers....

[Scrrem]

Boy it really pays to read through some of these posts. I got to looking between my radiator and oil cooler today and discovered a fairly significant "Mouse House". After two hours of cleaning, I think I got it all. This is a picture of about half of what I pulled out of that small cavity. The Z should runn cooler this summer :o
Rich

[Kevin]

that's the problem with these bottom breathing cars, they tend to heat up in traffic. I was a nervous wreak driving into carlisle and BG before I bought a mark haibeck chip for my car....now I'm still a wreak but it takes longer

[A26B]

Debris in the radiator is sort of like an iceberg, you can only see the tip of it from the outside. What really affects air flow is imbedded in the core. The only way to effectively clean it out is to completely remove the radiator & blast with high pressure, like at a car wash.

[Kevin]

Debris in the radiator is sort of like an iceberg, you can only see the tip of it from the outside. What really affects air flow is imbedded in the core. The only way to effectively clean it out is to remove it & blast with high pressure, like at a car wash.

i woulda thought this would damage the fins

[A26B]

Well, you need to exercise some caution with how close you put the nozzle & keep it parallel with air flow direction.

[Kevin]

good to know jerry, thanks for posting it. I would have never thought to do that

[tomtom72]

After you go thru all the work to take the rad out for cleaning, don't forget the A/C condenser. Grainger sells some worth while chemicals to clean the condenser if water alone isn't getting it done. Also pick up a fin comb to straighten out the fins.

Also, you may want to try this mod from Scott Fabre. It's not the best looking thing but it works like a charm and the only time anyone can see it is if they lay down in front of the car.
http://zr1netregistry.com/ZR1_radiatorscreen.htm

:cheers:
Tom