engine fan (rear) is on all the time, porsche 997

[scottydog1979]

Hi ive got a 2005 carrera s 997, ive owned the car for around 7 months, I noticed a couple of weeks ago that the engine fan was running when I returned home after a short trip to the shops, from this point onwards I started monitoring it and have found that once the water temp hits dead centre and the oil temp gets to 90 degrees the rear fan comes on and then wont go off at all during that day even if you leave the car for a couple of hours to cool it still comes on when you start the car, the temperature gages don't really move at all so I don't think its over heating, the only time it doesn't come on straight away is if its been stood over night, ive changed the temp sensor located in the engine compartment but its still the same, can anyone offer any advice or should I take it straight to the garage ?

[one eyed mick]

Imay be completely and uterly wrong so please forgive the following if it is wayoff ,--do not porkie fans only run when needed i.e to keep temps at correct level ,so on cold start no fan rotation but up to correcttemp runs to keep eng at correct temp as in a stat opening on others?. I,m probably way off please correct me if I am

[Thom]

Check the relay for the fans.

[scottydog1979]

Where is the relay for the fans and can I swap with another one from somewhere else to check ? Or should I buy another one.

[Thom]

Ok, there seems to be no fan relay on a 2005 997, but there is a 80A fuse.

[scottydog1979]

I will check but if the fuse is blown then would the rear fan not come on at all ?

[Thom]

On a 997 I don't know but on most well-engineered cars fans are set up to be turned on when the relay or fuse fails.

[scottydog1979]

Thanks for the info I will check this out

[marcus85]

There used to be a fault with mk5 golfs when they did the same, I think it was a faulty fan. Ring up Porsche and see if there is campaign for it. If there is you will get a new fan fitted for nothing