Cooling Fan "On" a lot - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Couper1 · 03-04-2007, 06:25 PM

I've search in here to see if other radiator cooling fans run frequently,but all I found was discussions on temp gauges. My temperture gauge seems to be normal but my radiator fans are constantly kicking on and running a long time...and they're loud.
It's embarrasing. Even in cool weather, 60-70 degrees. Is this normal?? It doesn't seem right to me. :troll: Anyone have any info on this?

David N. · 03-04-2007, 06:31 PM

I believe the fans in the front turn on any time the A/C is on, among other things. They are usually on. Are you takling about the fans in front behind the bumper or the compartment fan in the passenger side intake vent?

Rodger · 03-04-2007, 06:37 PM

If you're radiators are plugged up and you're doing a lot of low-speed driving with the A/C on, expect lots of fan activity.

Perhaps it's time for a cleaning? Might want to verify your coolant is topped up as well.

Couper1 · 03-05-2007, 03:43 PM

Quote:

Originally Posted by David N.

I believe the fans in the front turn on any time the A/C is on, among other things. They are usually on. Are you takling about the fans in front behind the bumper or the compartment fan in the passenger side intake vent?

I'm talking about the fans in the front, They are on no matter what the temp is outside and they are extremely loud.

blinkwatt · 03-05-2007, 03:55 PM

Perhaps your are do for a radiator cleaning & coolant flush. How are you with a wrench? They aren't hard to do,only time consuming but well worth it.

My 99' is pampered tune-up wise w/ 55k on it and I "get on her" often and she never tops the 0 on the 180 and the fans never turn on unless the AC is on.

babur · 03-24-2007, 10:24 AM

Hi guys,

Along the same lines, my 2001 Boxster is making a very loud noise coming from the passenger side air vent while the A/C is off. It doesn't sound like a normal fan noise.

Does anyone know anything about it.

Thanks

Bob

MNBoxster · 03-24-2007, 11:16 AM

Quote:

Originally Posted by Couper1

I'm talking about the fans in the front, They are on no matter what the temp is outside and they are extremely loud.

Hi,

Yes and if your radiators are clogged, the Fans will make more noise as they try to suck the same amount of air through smaller openings(because of the restrictions).

Also, you are working the Fans harder and Hotter and so their bearings will wear out prematurely leading to Fan replacement...

Happy Motoring!... Jim'99

MNBoxster · 03-24-2007, 11:47 AM

Quote:

Originally Posted by babur

Hi guys,

Along the same lines, my 2001 Boxster is making a very loud noise coming from the passenger side air vent while the A/C is off. It doesn't sound like a normal fan noise.

Does anyone know anything about it.

Thanks

Bob

Hi,

I suspect what you may be hearing is the Shut Off Valve actuating and air rushing in to the Fuel Tank. This air is brought into the Tank through the hole that is located by the gas cap. This is actually normal. It is required for proper operation of the Fuel Tank Venting system and the Mass Air Flow Sensor.

The Shut Off Valve opens or closes depending on the load state of the Carbon Cannister. What you hear is the Shut Off Valve actuating, and many people have mistaken this to be a noise from the AC system.

On the 987, this was changed to a different design in the Tank Venting System. This system uses a DM-Tl (Diagnostic Module - Tank Leakage) Valve Assembly. This Valve draws fresh air from a filter and is located on, and integral to, the Carbon Cannister as a package. The change in its location, and operation, eliminates the venting sound. Hope this helps...

Happy Motoring!... Jim'99

Couper1 · 03-28-2007, 04:42 PM

Quote:

Originally Posted by MNBoxster

Hi,

Yes and if your radiators are clogged, the Fans will make more noise as they try to suck the same amount of air through smaller openings(because of the restrictions).

Also, you are working the Fans harder and Hotter and so their bearings will wear out prematurely leading to Fan replacement...

Happy Motoring!... Jim'99

Thanks Jim, and everyone else too. I will go in and clean out the front radiators. I'll post the results afterward. Great info!! Thanks

CJ_Boxster · 03-28-2007, 04:59 PM

Also keep in mind that if you are hearing a Fan like noise coming from the engine compartment during first 3 minutes of morning startups. That could be your Secondary Air Injection Vacum pump running.

And if its really loud and sounds unbalanced and you can see that the fan on the passenger side vent (behind passenger door) isnt spinning, then likely your Vacum pump is on its way out...

por986 · 05-04-2007, 08:01 AM

Can someone elaborate more on the passenger side fan? Is there a fan on that side only near the intake (when driving, that is where it sounds like it is coming from). If so, what is its purpose, when it "should" come on, why it is sooo loud, etc. Thanks!! I am often at a drive through or a light, and it kicks on causing people around to freak out. (it is kind of funny)

Also, which fans kick on when the car is off and sitting in the garage? Mine 2001 S does that up to an hour after having driven on a hot day.

Thanks!!!

porsche986spyder · 05-04-2007, 08:23 AM

Quote:

Originally Posted by por986

Can someone elaborate more on the passenger side fan? Is there a fan on that side only near the intake (when driving, that is where it sounds like it is coming from). If so, what is its purpose, when it "should" come on, why it is sooo loud, etc. Thanks!! I am often at a drive through or a light, and it kicks on causing people around to freak out. (it is kind of funny)

Also, which fans kick on when the car is off and sitting in the garage? Mine 2001 S does that up to an hour after having driven on a hot day.

Thanks!!!

It's totally normal, nothing to worry about. Your car is just trying to cool itself off. If they did not come on at all, then you have something to worry about.

por986 · 05-04-2007, 09:12 AM

Quote:

"It's totally normal, nothing to worry about. Your car is just trying to cool itself off. If they did not come on at all, then you have something to worry about. "

Good to know that it is alright, but can you help me understand the setup a bit?
Is there a separate fan on one side and if so, how is it different than the radiator fans, etc?

I am completely ignorant when it comes to this!

Much appreciated!

porsche986spyder · 05-04-2007, 12:51 PM

Quote:

Originally Posted by por986

Quote:

"It's totally normal, nothing to worry about. Your car is just trying to cool itself off. If they did not come on at all, then you have something to worry about. "

Good to know that it is alright, but can you help me understand the setup a bit?
Is there a separate fan on one side and if so, how is it different than the radiator fans, etc?

I am completely ignorant when it comes to this!

Much appreciated!

I was told that the fan on the passenger intake vent is for cooling the exhuast. The front radiator fans work to cool the entire car's engine. Hope this helps.

MNBoxster · 05-04-2007, 04:09 PM

Quote:

Originally Posted by porsche986spyder

I was told that the fan on the passenger intake vent is for cooling the exhuast. The front radiator fans work to cool the entire car's engine. Hope this helps.

Hi,

That's not quite correct. The Exhaust runs on both sides of the engine and consequently the car. The Fan is properly called the Engine Compartment Fan and is controlled by the DME from signals it receives from a Temperature Switch mounted between the #1 and #2 Intake runners. It's job is to control the temperature inside the engine compartment, not specifically the exhaust, and will usually, but not always, activate if the Engine Compartment temperature exceeds 180°. Hope this helps...

Happy Motoring!... Jim'99