Dubgw

cosm3os

Relax. It's fine.

yvesvidal

In my garage, I have been opening the rear hood, to let the hot air escape. It helps with the longevity of all plastic parts in the engine compartment and warms up your garage in the winter time.

Yves

bronz

this

Bruce In Philly

I don't think opening the hood is a good thing..... my 2009 will monitor the temps inside the engine compartment for 30 minutes after shutdown and will fire up the fans to cool if needed. The fans don't fire up if the hood is open (this has been the "knowledge" of the 'net, there is no mention of this disconnect in my manual). I have been in the garage 15 mnts after I shut down the car and the fans will kick in. The assumption is opening the hood will evacuate heat better/faster than the fans.... IMO, fans are better and are set at a temp the engineers defined as appropriate.

BTW, if you feel the fans are not working, you can use a Durametric to start and stop the fans at will. The dealership can do this also. BTW, the computer will flash the coolant temp warning light if it sees a fault with the engine compartment fan (from the manual).

Peace
Bruce in Philly

mujeriega

This is totally normal. Agree with Bruce to let the fans do their job... not to mention, if you open the hood in the rear, you'll be running that small light the entire time.

However, during the height of summer, it could be beneficial to get a fan to circulate air in your garage... I'm thinking of doing the same thing as I"m in AZ.

Petza914

The fans won't run if the lid is open as a safety precaution because of the spinning fan blades not behind a cage that fingers don't fit through. Also, the fans actually pull air from above and blow it out below which Porsche has determined is the most effective way to cool the motor. Ope I g the lid only lets heat rise up through which isn't as effective.

Leave the lid closed and let the fans work as intended. Now there is a temp sensor that monitors the temp in the engine bay, which is what controls the fan. If this isn't positioned properly or has gone bad, it may not kick the fans on.

linderpat

As always, Pete is spot on. Also, the converse not yet raised here is when the fan runs and does not shut down for a long period after the car is turned off (I think the max time it can run is 20 minutes, then it shuts down no matter what). I had that issue recently. Turns out the little rubber o-ring that holds that sensor in place, suspended in the space between two of the intake runners on the passenger side, had become dislodged, causing the sensor to rest on the hot engine itself. Even after short drives, the fan would kick on and not stop. Very easy and cheap fix to replace that little o-ring and remount the sensor.

yvesvidal

On my car 2006 C4S, the fans will not run as soon as you shut off the ignition. It is probably different on newer models.

On the other hand, the expansion vase for the coolant is impeccable and does not have any cracks after 12 years and 80K miles of service.
Finally, the fans are pushing the heat downward, which is contrary to the physical properties of hot air.

Now, you guys do what you want.

Yves

jhbrennan

Two schools of thought on lid open or closed - with hood open all the heat from headers, cats, etc. rises over the plastic and rubber on the top of the engine. Hood closed and fan running pushes heat from engine, headers, etc. down and out under the engine. I'm in hot Texas and have done it both ways - can't really tell if one way is better than other, although on really hot summer days in an enclosed garage, I'll position an exhaust fan to blow under the car to push the hot air from the car fan out a slightly end garage door.

ADias

The fan is there to cool the engine actively and pulls air from the outside down to the floor. But I do not think that there is any issue opening the engine lid in a garage as the large opening will facilitate efficient convection.
Another way to help an engine cool down in a warm garage is to put a fan in front of the car with a significant air flow moving under the car.

Now... I do not think that helping to cool the engine in the Winter, even in a garage, is a good thing. The same way that an engine should heat gradually it should also cool down gradually.

user 72902

Everybody put down your weapons and take two steps back. Seriously most cars do not have cooling fans and they are all hot when you turn them off. Most will let the fans blow in front of the radiators for a bit but I think that heat build up in the engine bay is factored into the design of every car. Opening the rear deck and running a fan might help but I don't think bore scoring or other catastrophes await if you don't.

evo9

I'm in South FL also (2010 c2s) and what I've started doing is let car sit in driveway for 1-1.5 hours before putting it in the garage. IMO - engine/muffler heat seems to dissipate better when left outside in open vs putting it right in a closed 2-car garage after driving. I've definitely noticed my garage does not heat up as much when allowing car to cool outside vs driving it right into garage.

Good luck,

WW

991997996

Cars engines run very hot because the catalysts need to burn off the nasty stuff coming out of the engine before it passes the exhaust through the tail pipes.

squeegee

For the guys who have fixed the temp sensor. Need help on the location. I can't seem to find it.