Funny noise when turning engine off on 320 cdi

[jubhi]

Hi,

I'm getting a funny noise when turning off the engine on my CLK320 CDi :roll:

Basically when I turn off the engine there is a sort of noise like a pump that is working for 10-15secs and something turning inside it and that it seems to get stuck sometimes and then stops. This happens everytime I switch off the car, you cannot hear it inside the car but when outside and you get someone to turn off the car then you can hear it and I don't know if it is normal or not.. :roll: There is a whining noise that lasts for 10-15secs which seems normal and highlights something is in operation, but the noise that worries me is that something inside is getting stuck, like a pump motor starting and stopping, this happens 3 to 4 times within the 10-15secs post engine turn off. Sorry but this is the best explanation I can give.

I have got a picture from the web of a 320 cdi engine and highlighted where exactly the sound is coming from.

Any advice will be greatly appreciated. Thanking you in advance.

 

[hawk20]

I am no techie but have come in to keep your thread alive till an expert sees it. It was at the foot of the page and ready for the big drop.

My only thought is could it be that the aircon goes on for a while after the engine is switched off? If nobody comes in PM Malcolm.

 

[mattsurf]

This sounds like the diesel heater - when the outside temp is below 8 degrees my E320 cdi has a Diesel heater which warms the air fed into the car - once up to temperature the heater shuts off. If I make a short journey in the cold weather, I notice that the fan on diesel heater caries on for 10 - 15 seconds and is accompanied by a slight smell of burning fuel (this is noted in the drivers manual so I am not worried about it)

Does your car do this just on short journeys?

 

[hawk20]

This sounds like the diesel heater - when the outside temp is below 8 degrees my E320 cdi has a Diesel heater which warms the air fed into the car - once up to temperature the heater shuts off. If I make a short journey in the cold weather, I notice that the fan on diesel heater caries on for 10 - 15 seconds and is accompanied by a slight smell of burning fuel (this is noted in the drivers manual so I am not worried about it)

Does your car do this just on short journeys?

I didn't know that. Presumably, I had the same on the S 320cdi? It had a switch on the gearbox tunnel for extra heat in cold weather. Does the E have that or does it just happen automatically.

Wonder if the A class has the diesel heater too? Need to read that handbook!

 

[mattsurf]

On my W210 you have the switch which allows you to turn the heater off - however, I understand that in the W211 the auxilliary heater is present, however, you don't get the button to turn it off - I presume that it is all integrated with the normal heater controls

 

[jubhi]

I am no techie but have come in to keep your thread alive till an expert sees it. It was at the foot of the page and ready for the big drop.

My only thought is could it be that the aircon goes on for a while after the engine is switched off? If nobody comes in PM Malcolm.

Thanks Hawk,

Just to let you guys know this noise is perfectly normal, I went to the dealers and checked out 2 cars one of which was a brand new CLK320 CDI just like mine and it made the exact same noise for 10-15 secs post engine switch off, we also tried an E320 CDi which was 6 months old and it did the same.

The technician said it is the air pump actuator and that this sound is normal and nothing to be worried about, so I'm happy about that.

Thanks for keeping the post alive though

 

[hawk20]

Thanks Hawk,

Just to let you guys know this noise is perfectly normal, I went to the dealers and checked out 2 cars one of which was a brand new CLK320 CDI just like mine and it made the exact same noise for 10-15 secs post engine switch off, we also tried an E320 CDi which was 6 months old and it did the same.

The technician said it is the air pump actuator and that this sound is normal and nothing to be worried about, so I'm happy about that.

Thanks for keeping the post alive though

Thanks for letting us all know. Do you happen to know what the air pump actuator is? Part of the aircon? Or heater?

 

[jubhi]

The technician said it acuates and controls the amount of air flow into the engine, the unit itself is connected to a large cold air feed pipe just left of the offside front fog lamp housing.