jclanin

Hi all,

Recently I've noticed a slight hum like a fan or blower is running constantly.

any ideas?

thanks,

JC

Marlon

Where is the sound coming from? Front left, front right, engine compartment? ARe you talking about a fan running 'after you shut it down'? Or while the car is running? Is the a/c on or off??? What is the oil temp? And so on. What are the details on your situation???

How long
Where
when
etc....

jimq

its may be the the small fan on the back of the CCU. It normally runs for a time after the car shuts off. A resistor(transistor?) can go bad in the CCU in which case it will run all the time.

jclanin

I should have been much more detailed... sorry.

It runs all the time when the engine is running. AC off. Oil temp is fine. Sounds like it's coming from the engine compartment. It's very subtle - but I'm sure it's not normal.

I could be wrong, but I don't think it is the small fan of the CCU - just does not sound like that fan. It's more of a constant hum.

thanks,

--JC

PDriver

Maybe it is the idle control valve....

PDriver

ZombiePorsche44

There is one fan that runs constantly on 993's, it is located in the dash and is the Climate Control Unit fan that blows air over the cabin temp sensor next to the climate controls, there is a second fan in the engine compartment that is also coupled to the Climate Control Unit and is a booster fan for the heat exchangers that will run for a pre-determined period after the car is shut off .

Hope this helps......................ZP44

cowtown

If it's the large ventilation motor in your engine bay, look at the temp. sensor installed on the side of the black plastic duct - maybe someone has a picture of this at their fingertips. If it's unplugged or shorted, the vent motor runs constantly.