Temperature is running 250+ and I'm trying to identify soucre of the problem. I can tell when the thermostat opens because the temp drops for a brief moment, but soon comes back up. Fans appear to be working properly. Visual inspection shows nothing is blocking radiator, belts are fine, etc.

I am thinking:
1. Replace thermostat?
2. Bad water pump?
3. Blown fuse?
4. Computer problem?

Any advice as to where I should start to look.. or how to narrow this problem down? Are there computer codes I can read that would help me identify my problem? If so, how can I read the codes?

Cheers,
Dennis

 

I would pull the thermostat...

 

First of all, have you recently changed the thermostat or water pump, etc.? There is a specific routine you need follow to make sure you have purged all air possible from the cooling system. I have also found that the PCM does, on occasion, give- shall we say, accuracy challenged readings to the gauges. In my case, I thought the oil pump had gone out. I agree that the thermostat would be #1 place to start, and before going any further if that doesn't pan out, I would try an oven thermometer or mechanical gauge to verify that the gauges on the dash are indeed telling an accurate story. Good luck.

 

Are you sure your radiator isn't being blocked externally from road debris? I air hosed out a bunch of leaves that were sucked up against the radiator in my vette this past weekend.
Norm

 

Is the gauge broke or malfunctioning? are the fans running continually? Is the proper coolant in the system? and is it full?

 

Thanks Guys.

1. No debris in radiator.
2. Never changed any water pumps etc.
3. Thinking of replacing thermostat... with 170 degree model.
4. Gauges are accurate according to my digital temp gauge.
5. Coolant is full.
6. Once temp rises ... fans run constantly.

If I do #3 do I need to do anything like reprogram the fans, etc... or will it tun OK without re-programming? I figured that if I am going to change the thermostat... I might as well get some perofrmance increase!!

-Dennis

 

Take a High pressure are hose and blow the dirt out of the radiator. You will be supreised what you dont initally see that will come out with the air hose.

Then do a coolent flush.

One or both should fix the problem before you go diving into a new t-stat

 

Dennis,
Not sure what you hope to accomplish by changing the thermostat. If it is stuck closed it would help to change it but you state you can tell when it opens. What temp does it open at? If it opens at 195 putting a lower thermo in will not solve your problem since the 195 should be all the way open long before the temp hits 250 all the 170 will do is open sooner. All the thermostat does is set the minimum temp of the coolant not the high temp. It sounds like you have lost some cooling capactiy through blockage in the radiator (check for grass, leaves or other debris in front of the A/C Condensor all the way at the top) or you have some problem (like a blown head gasket) that is causing the engine to run hot.
Bill

 

[QUOTE=AU N EGL]Take a High pressure are hose and blow the dirt out of the radiator. You will be supreised what you dont initally see that will come out with the air hose.

I got this much dirt, not counting leaves and grass, after blowing out my radiator and A/C condenser which is in front of the radiator.

[IMG][/IMG]

 

There are TWO areas where dirt and trash can collect. The area inside the radiator air inlet and in between the AC condensor and the radiator!!

If you pull the plastic radiator cover off (the one below the air bridge) you can see that area. It is normaly full of grass and trash!

Hope this helps solve the problem.

BC

 

Thanks guys. Will pull the shrouds off tonight and check for something blocking radiator or A/C. It did seem odd....

-Dennis

 

You should definitely use a high-pressure air hose to blow your radiator/condenser clean. My 02 Z06 temps were running around 230-240. It is now running 198-207. I cleaned the radiator/condenser around 3-4 months ago. You will be shocked at the amount of crap you blow out. I took the fans out in order to get to as much of the radiator surface as possible. Do a search under my forum name and you should find a VERY detailed description of this easy temp fix. Good luck.

 

This floor was clean before I too the air hose to the radiators.



All from just ONE weekend on the track. So what would several months if not years look like????

 

After you clean out the junk you are going to be finding in your radiator, get yourself some screen and make yourself a guard to keep junk from going up into the radiator opening. It should fit between where the five screws hold the shroud to the bumper and back towards the spoiler. Go to a building supply store and buy galvanized or aluminum screen, it's pretty cheap to do. I found a McDonalds french fry container up there.

 

i notice that you are in the bayarea. you can take it to synergy in fremont and they can help you. they are verygood in finding problems.

 

pull the radiator shroud and blow it out before you start spending money.

 

1. To read your codes:
Turn the ignition to ON but don't start the vehicle.
Push RESET to clear any error codes on the DIC.
Hold the OPTIONS button down and keep it down.
Push the FUEL button 4 times within 5 seconds.

The DIC will then display your status for each of the modules in the vehicle with number of error codes for each and then the actual codes. It will scroll through all automatically (far too quickly to copy info, but don't sweat it.) Once its through in AUTO it will display MANUAL MODE or something like that. The use the (I can't remember all the names from the top of my head) 4th button from the top to scroll FORWARD through the groups (3rd from the top scrolls backward by group) till you find a group that says you have codes. Then use the 2nd button from the top to scroll FORWARD by code (Top button scrolls BACKWARD by code). They should stay displayed till you make another selection. There should be a letter and then 5 numbers and then either an "H" or a "C". The H / C denotes whether the code happened prior to the last start or during the last time the car was running. "H" codes stay with the car during a period of 50 starts and then clear themselves. You can clear them by pushing the reset button while the code is displayed.

2. As for overtemping. Not sure of the age of your vehicle, but a collapsing radiator hose will also create a condition like your describing. Once they're old, they can collapse internally and choke off the supply of coolant. The low tech checking method for checking this is to just squeeze the upper radiator hose with your calibrated fingers to see if it feels overly "soft".

3. Changing the Thermostat to a lower temp without reprogramming the fans will only change the engine temp at cruise (possibly) depending on ambeint temps, etc... I'm sure if they have them for the Vette, but I know you can get plug-ins for some vehicles to fool the computer into turning the fans on at the lower temp instead of having to get it reprogrammed.

Hope some of this helps. Take it easy and good luck. Let us know what fixes it.

 

Your car is a 2001, it's five years old...
The air foil in front of the car directs anything airborne up into the condenser fins... many people look up there think it is the radiator and clean blow or vacuum the debris out... the worst thing you can do is blow it out from the condenser side.. this will only help to load up the radiator which sits 2 inches behind the condensor... I am willing to bet that the radiator fins have never been cleaned... you should flush and blow from the backside of the radiator, putting a piece of cardboard between the radiator and the condenser so you don't blow the debris into the condenser.... with the right technique you can make your car as cool as it did when it was new... and with the right technique you should see a lot of sand, pollen, dust *****, fuzzies bug guts... most 0f the stuff that blocks the condenser and radiator is way too small to be stopped by a radiator screen.... it will however stop an armadildo <--- : )
from getting stuck up there..
the other thing that happens to these cars is the coolant recovery tank cap does not hold pressure... this usually shows up as a collapsed upper radiator hose.. with the hot engine turned off.

 

Hi L76 -

Good info in this post so far -

One other thing I have heard mentioned is that the front air-dam is necessary to direct cooling airflow up to the radiator.

It that airdam has been modified or removed, you could see higher temps - or so it has been posted here before.

good luck!

best regards -

mqqn