If it is the rear deck lid fan it will throw a code. It should not be running unless the engine bay temp is above the preset limit. If it is coming on when the engine is cold there is a problem either in the DME setup or the fan itself.

 

I had a fan on one side running strong once and it was because I had a small rock stuck in the other non-functioning fan keeping it from spinning. Once I removed the rock both fans work as normal.

 

Is there a way to get to fan from underneath? Or does bumper have to come off? It happened again...loud and a lot of air from right and none from left...

 

Note that in my case it wasn't the fan that was causing this symptom, it was the fan controller... the fan itself was fine. Regrettably, I don't know how the dealer diagnosed the difference.

 

Thank you for your help . I'm going to start a new thread on how to check it. Maybe if I can get to fan I can see if its clogged or if I disconnect it and put power to it , see if it kicks on . Its just strange that this is first time it happened again since I started last thread . Maybe if its that module you had changed , I can get to it and change myself ?

 

I had the same issue, only one fan on with loud noise...Remove bumper and clean the area, if needed clean between radiators too. Its best to install mesh grill on bumper to avoid this problem in future.

 

The bumper doesn't need to come off to access the fans. You get to it from the wheel well and remove the black plastic piece that the fan vents out of. IIRC it's an awkward shape but not too difficult to remove and reinstall in your driveway.

 

Another one of my questions ...The temp here in New Jersey is in the 20s . What I was wondering is that will those front fans try to come on when its this cold ? Yesterday it happened after ride home from work ...I cleaned a ton of stuff from in front of radiators ( nothing by fans yet)...today same temp , drove car hard from work ( 40 min) , no loud fan noise...with it being this cold, is car always going to get to temp to kick the fans on?

 

The fans are variable speed so if it is a cold ambient temperature you may not notice the fans running as if it were hot outside. Typically after the car is up to temp and while you are sitting idle you can feel hot air rushing out from the front wheel well as an indicator if your fans are on or not. If it is cold outside and the car's not running that hot you may not feel much air flowing at all.

 

You don't need to feel for hot air... you can clearly hear the fan when its ON. My one loud fan from front was ON even on cold temp here in Canada.. mine had nothing to do with fan being blocked, I only cleaned the front of radiators and problem solved! So after you cleaned did it come back ON again??

 

I cleaned radiator a few days ago and haven't had any problems at all. Went on a few 40-50 minute drives and no loud fan running on passenger side . Seems OK. I have an appointment to drop off car tomorrow, but I'm not sure if I should even bother . I just don't want to cause any damage , but on other hand should I wait till problem ( if there is still one) becomes constant?

 

Its a known issues with 996-997. A good thing would be to add mesh grills on bumper to avoid debris getting in there again. But I think you fixed to problem.

 

What i would do is as soon as it happens, I would drive straight to the dealer. Nothing is worst than dropping it off and they find nothing. Intermittent issues are always frustrating.

 

I had same issue

 

Finally going to bring it in..Just want to pick your brains one last time... It happened again ...passenger side fan on full blast and no air from drivers side ...I thought I had it after I cleaned out front of radiators last week ...just wanted to ask what you guys thought the problem would most likely be since I went almost 10 days without any problem ..the fan or control module ? I don't think it could be debris cause it would not be so intermittent ...anything else to look for?