997 turbo - when does your fan go on? - Page 1 - 911/Carrera GT - PistonHeads UK

I got the "Engine comp. blower failure" message on the dash recently. Charles Ivey replaced the fan unit, warranty covered it. So far so good. However since the replacement I have not heard the fan once after parking up - I am sure it usually came on after most drives, even relatively short ones. On Sunday it didn't come on after an hours drive to Dunsford on a sunny morning. I do however always allow car to warm up before pressing on, and allow it to call down at end of journey. Only had the car 3 months so not sure what is typical - so before I go back to Charles Ivey to complain, how often does your fan go on?

Check your car's fuse diagram. There might be 2 engine compartment fan fuses. One is to allow the fan to come on when the engine compartment temperature reaches a threshold. The other fuse -- when present -- causes the fan to run all the time. This is the way the 996 Turbo engine compartment fan is wired and works. My 996 Turbo's engine compartment fan runs all the time the engine is on.

Same here, 996turbo fan on all the time the engine is running. Unlike the C2, C4 etc which is rarely on and is engine compartment temperature switched. Sucking air in (not blowing out) as discussed at great length on another forum with a Poll.

Ok but does it switch off once engine turned off or continue for a while? Anyone with a 997 confirm?

Mine rarely goes on on my 997.2 turbo as I tend to run the car at low speed after a high speed run due to the nature of my local roads. Complete opposite to the boxster which came on a lot and stayed on for quite a while after engine had been switched off. I would expect the turbo does the same if the conditions required it.

Adam B said: Ok but does it switch off once engine turned off or continue for a while? Anyone with a 997 confirm? Hi Adam I had a very similar issue when I had my 997.1 Turbo. From what I remember after a few pointers from chaps on here it is a fairly common thing on Gen1 997's. I believe there are 2 fuses in the rear box that are located near the subwoofer so a bit more of a pain to get to. If I recall correctly, one of the fuses amp rating is not high enough so has a tendency to blow causing rather erratic fan operation. Mine showed up as a blower compartment fan fault on the diagnostics and was then sorted as it then only came on after a long run. The OPC also said to be at the time it was my compartment temp gauge sensor also at fault which compounded the issue. Anyway was all changed and seemed to be ok after that...

berty37 said: Hi Adam I had a very similar issue when I had my 997.1 Turbo. From what I remember after a few pointers from chaps on here it is a fairly common thing on Gen1 997's. I believe there are 2 fuses in the rear box that are located near the subwoofer so a bit more of a pain to get to. If I recall correctly, one of the fuses amp rating is not high enough so has a tendency to blow causing rather erratic fan operation. Mine showed up as a blower compartment fan fault on the diagnostics and was then sorted as it then only came on after a long run. The OPC also said to be at the time it was my compartment temp gauge sensor also at fault which compounded the issue. Anyway was all changed and seemed to be ok after that... Can you confirm what "ok after that" operation is like though? Does it rarely come on after engine switched off? My series of events 1. fan used to come on regularly after engine off 2. get warning message 3. garage does work, including replacing the fan 4. no warning messages, engine temps seem fine 5. BUT fan now has never come on after engine off I expected the fan to come on briefly, just to get rid of excess hot air, after a long (not necessarily fast) run. Or should I just not worry as if there was a problem the wanring would ocme on?

Mine rarely comes on after I switch car off unless the car has been put through its paces or its a hot day.

IMI A said: Mine rarely comes on after I switch car off unless the car has been put through its paces or its a hot day. thank you, exactly what I hoped to hear

Only had mine running two or three times over the last year.. and that was on a hot day.

If you run the engine at idle from warm and place the ac on to add some engine load the fan will run after approx 5 mins. It is connected to the lid switch so does stop if the boot (new to Porsches hope this is the correct wording lol) is opened. I understand a temperature sensor is located behind the bumper which activates the fan and the engine off fan run on timer to stop overheat and fuel evaporation in the lines if the bay goes above a certain temp. When driving the compartment get natural ventilation. Hope this helps. 997 TT Gen 1

Interesting - so maybe my old fan coming on all the time after turning off engine was an indication it was faulty

IMI A said: Mine rarely comes on after I switch car off unless the car has been put through its paces or its a hot day. Same with my 997.1 turbo.