Hey guys, Just recently i've been having a problem with my 02 ws6 overheating on the highway. Around town the temperature is fine and never goes above the half way mark on the gauge. But when I get up around 75 and higher on the highway if the A.C. is on i'll notice that first it starts to get warm and next thing the temp. will start shooting up. The same happens if I turn the A.C. off or it is turned off the whole time. The first time it happened I didn't even notice until the "check gauges" light came on and the thing was in the red zone! Then as soon as I get off the interstate the temp comes right back down to halfway point again. This has only started in the last week or so and does it every time now I get up to higher speeds.

Is it possible that the radiator fan isn't coming on because the car thinks it doesn't need it because of the high speeds? Any help whatsoever would be much appreciated...

 

What year is you car, also what mods do you have? how many miles, auto or m6?

 

That sounds a lot like hot combustion getting into the cooling system....meaning a leaking head gasket or crack somewhere. I had the same thing happened to me....as the rpms go up, more heat is transferred to the cooling system via the leak. In my case, it was a head gasket. Good luck, I don't think the fans have anything to do with your problem.

 

I believe unless the a/c is on, the fans are disabled above 30 MPH because there is already enough airflow. Perhapsy youre fans are not turning on at all. Turn on the a/c to max and take a look to see if the fans are on. If not, maybe you have a bad relay or fuse or something.

 

The reason I don't think the fans are the problem is that you don't need the fans at the speed he is going when he has the problem. That's why they turn off, because there is enough airflow to keep it cool at that speed. Plus, it starts to overheat when he is at higher speed, not when he is idling or at low speed.

 

Youre right, i read that backwards. Maybe a coolant passage is blocked or the thermostat isnt opening up?

 

Check your oil level. Just a quart low in 100+ degree heat make mine run 10-20 degrees hotter.

I assume that you have checked the coolant level?

Steve

 

First thing I would look to see if any road debree found it's way in front of the ac condenser. If it is clear check fluid levels. If that looks ok have someone pressure test the cap and coolant system. Other than that the thermostat, and swapping to an lt1 radiator can cool it down. Run the motor up to operating temp with the cap off starting from a cold start. Check to see if the coolant is flowing well.

 

that happens to my ride also...i added some oil and it went away...but i think im going to flush the radiator...see what that does