I was wondering if any of you had experienced this heat related behavior. My Turbo has a MAShaw GT2 wing, GIAC Stage 1, and DV's.

Every now and then I will get a BC warning something to the effect "Engine compartment fan failure...". The fan is working and I can actually hear it running so I have been ignoring it. The temp gauge reads about 180-185.

Yesterday I was driving down the road and saw a friend pulling out of his driveway. I stopped and left the car running while we talked for about 10 minutes. The outside temp was about 90 degrees. We were talking behind the running car so I could hear the auxiliary fan. It was running.

I got back in the car and drove away. About 100 yards down the road I get the BC warning again and this time the little red "idiot" light at the top of the temp gauge is flashing. The gauge is reading 180-185.

I got home parked the car in the garage and took note of the auxiliary engine compartment fan. it was running fine.

Anyone have any ideas what is going on here? Any help would be appreciated. Thanks

 

First thing, hook up your scanner and find out what the actual coolant temp is. Highly unlikely that it is less than 205F idleing in 90 degree sun. Secondly, check the connection of the fan wire to the sensor on top of the intake. If this is disconnected or loose, the fan runs but the light flashes on the temp gauge. Your scanner will also show -40 degrees for the engine compartment temp if it is disconnected. Also, check the the fan is sucking the air INTO the engine compartment by placing apiece of paper on top of the id when the fan is running. Also check coolant level.

 

1999Porsche911, thanks for the help. The next time it happens I will pole the temp with my scanner. Duh, Don't know why that wasn't obvious to me. I want to make sure I understand the last suggestion you made. You said sucking air INTO the engine bay. I believe my fan blows air out of the engine bay. At least I can feel the air blowing out of the grill with the deck lid closed. I'll double check tonight. Thanks again.

 

1999Porsche911, thanks for the help. The next time it happens I will pole the temp with my scanner. Duh, Don't know why that wasn't obvious to me. I want to make sure I understand the last suggestion you made. You said sucking air INTO the engine bay. I believe my fan blows air out of the engine bay. At least I can feel the air blowing out of the grill with the deck lid closed. I'll double check tonight. Thanks again.

 

Make sure that the fan is sucking in fresh air and NOT sucking hot air out. There were some 996's that had the polarity reversed on the fan cable that had to be corrected years ago. If you pull the air out through the lid, you are drawing hot exhaust system air from the bottom of the car into the engine compartment. Sucking in fresh air from the top will keep the engine at it's coolest.

If your fan is coming on regularly, during normal driving, you have a problem. Either your coolant is too hot (unlikely) the engine compartment is above 180F (unlikely) or the fan cable to the engine comartment temp sensor is not connected or loose or sensor is bad. Could be many other things, but this is the most likely cause.