Engine compartment fan: suck or blow?

[Dennis Nicholls]

Dumb question time: Does the engine compartment fan behind the passenger's side vent (US) suck cool outside air into the compartment, or does it blow out (exhaust) hot air from inside the engine compartment?

I've got a boxer fan in the garage that could be used to help cool off the engine and I don't know which direction would be the most helpful. IIRC the owner's manual says to let the car idle for 2 minutes after driving but I doubt anyone does this.

[Loren]

The engine compartment purge fan brings in cooler fresh air when the engine compartment temperature exceeds a preset value.

[lkchris]

Not to mention cleaner sir.

[RFM]

With all due respect particlewave, there must be something wrong with the rotation direction of the fan on your car. There is effectively outside air blown over the engine as indicated by Loren, hold a sheet of paper against the grille when the fan is operating, it remains sticking to it.

[Loren]

particlewave - I am sorry but you are wrong.

Here is the functional description of how it works from the Boxster (986) Service Technik.

(click to enlarge)

And... just to clarify I am a moderator as well I am the site founder and owner.

and RFM is volunteer moderator and former Porsche factory employee.

[wang]

Loren or anyone,

 

Can you supply the relay part number?  Pelican does not know the number.  Bently manual shows relay on page 97-12

as #8 (09/2005).  I found the fan unit as part # 986.624.0.36.00.  I'm using the least expensive to the most.  Fuse, relay and fan.

 

Thanks,

 

Bob

[Loren]

Loren or anyone,

 

Can you supply the relay part number?  Pelican does not know the number.  Bently manual shows relay on page 97-12

as #8 (09/2005).  I found the fan unit as part # 986.624.0.36.00.  I'm using the least expensive to the most.  Fuse, relay and fan.

 

Thanks,

 

Bob

 

141 951 253 B Relay -- US MSRP $21.42

[wang]

hello,

 

1999 porsche boxster tiptronic 42,500 miles

 

engine cooling fan not coming on.

 

replaced fuse, relay, took the car to a local mechanic.

he disconnected the fan from the car's electric system.  hooked up

a 12 volt battery and started the fan.  he then went to the temp probe between #2.

he removed the probe and heated with a heat gun.  the fan went on.

 

what am I missing?  is there some dme issue?  a broken wire or connection?

 

I used an Actron reader and the result = "no codes"

 

I use the paper towel test on the intake vent while the temp gauge is showing 180. the towel will not stick.

 

thanks for your help

 

wang

[Loren]

hello,

 

1999 porsche boxster tiptronic 42,500 miles

 

engine cooling fan not coming on.

 

replaced fuse, relay, took the car to a local mechanic.

he disconnected the fan from the car's electric system.  hooked up

a 12 volt battery and started the fan.  he then went to the temp probe between #2.

he removed the probe and heated with a heat gun.  the fan went on.

 

what am I missing?  is there some dme issue?  a broken wire or connection?

 

I used an Actron reader and the result = "no codes"

 

I use the paper towel test on the intake vent while the temp gauge is showing 180. the towel will not stick.

 

thanks for your help

 

wang

 

It is not a cooling fan it is a purge fan and only comes on when certain criteria are met.

See the image below (click on it to enlarge it) for the details of how it is triggered.