Invisible Motor

[kevinororke]

Hi, another unidentified noise paranoia problem. I've got a W202 C Class diesel auto. On switching off the ignition after even a short run a motor / pump continues to whir for a few minutes. This is not the usual suspects eg cooling fan or air con and obviously can't be any of the engine driven pumps. The noise comes from directly under the air filter box and can also be heard coming from the drivers side wheel arch. I'm sure it is not a problem. But what is it !

Regards, Kevin

 

[television]

Hi, another unidentified noise paranoia problem. I've got a W202 C Class diesel auto. On switching off the ignition after even a short run a motor / pump continues to whir for a few minutes. This is not the usual suspects eg cooling fan or air con and obviously can't be any of the engine driven pumps. The noise comes from directly under the air filter box and can also be heard coming from the drivers side wheel arch. I'm sure it is not a problem. But what is it !

Regards, Kevin

Don't worry too much , I have not worked out what all of the clicking and things running are yet on mine, it does settle down in the end, and goes to sleep.

Malcolm

 

[Uncle Benz]

You don't state what engine or model you have, but you are probably hearing a small electric pump that circulates coolant for a few minutes after switch off. This helps to prevent damage from localised hot spots within the engine/turbo*/alternator*

* ancilliaries dependent on model/engine type.

 

[kevinororke]

Thanks Uncle. It's a 2000 (X) 220 CDI Estate. What you say is reassuring. One of the problems is that this model year seems to be a bit of an engineering hybrid which shares some of the features of the W203. Eg tiptronic auto and glow plugs which never seem to be needed. The Haynes manual does not list some of the options on my car and consequently is not much use a a reference. I'll take TVs advice and ignore the noise.

Thanks, Kevin