Join Date: Sep 2007
Location: Ralston, NE Chasin' cones and droppin' lap times
Electric fan not running when HOT?
I ran a couple of lapping days in my 97 GT last weekend and had an over heating situation occur that puzzled me. At the end of a 20 minute session of hard running the temp gauge had finally climbed to the far side of the "L" in NORMAL. I did my normal cool off lap and and was expecting the temp to start to drop a little. It actually went up a bit more. When I pulled into the paddock the car started puking coolant out of the radiator cap. I left the car running to keep coolant cycling thru the radiator when I realized that the fan was NOT running. We had just put a new CCRM in the car a month or so before and everything had been working fine. I then tried to see if the fan would kick on when I turned the A/C on which should trigger the high speed fan. Still no fan. The temps started to drop a little (I had put the nose of the car into the wind to try to help the situation) and I shut it off and let the car cool off on it's own.
I came back to it after 30 minutes and started the car to see what was what. I turned the A/C and the fan kicked right on like normal. I let the car sit and idle and it came up to its normal temp and the fan cycled like it should. I washed the spilled coolant off the engine bay and refilled the overflow with straight water (it took a couple of times as it re-entered the system)
I went back out for my next session and I was really watching the temp gauge. I didn't let it get quite as warm this time and came in early. I didn't hear the fan running from inside the car when I came into the paddock so I immediately went out the gate and drove around on the public roads to get air to the radiator until the gauge got back to the cool side of the "A" in NORMAL. When I got back to the paddock the fan was finally on.
So, here's my question: Any reason why a fan would act like this? Not running when the car is pretty darn hot but runs fine in normal operation?
The car is a 97 GT with no engine mods. I turn the heat on in the car to try to help keep things cool in the engine. I am planning on doing the fan switch mod after what happened this weekend. I'm also thinking of going to a 03-04 Cobra radiator or a Mishimoto.
97 Mustang GT, 92 Civic Si, 93 Escort LX (the "Escargot"), 01 Ram 1500 4x4
2007 SCCA RallyX RPF National Champion! 95 Neon ACR (totalled 2/5/08)