2005 Mercedes - Weird Noise

I drive a Mercedes CLK and have done for the last 4-5 years. This, however, is a very recent problem.

What I have noticed is that if I drive somewhere in which I only need to be out the car for a couple of minutes, say I’m nipping to the shop or filling up with petrol, within a minute of restarting the engine and driving off there’s this really weird sound which I can only describe as a whirring noise.

It only ever happens when I restart the engine within a window of about 1-30 minutes after killing it. I can go to the gym for an hour and it won’t happen, I can leave the car overnight and it won’t happen - it’s only when I restart the car soon after I’ve stopped it where the noise happens and for the life of me I do not understand it. I’m wondering whether it’s something related to an alarm somewhere(?) but this has only been a recent issue, it never used to happen.

Any answer/advice/suggestion would be much appreciated.



Can you post a sound clip?

Which engine? How many miles?

Noisy air injection pump, they are electric and sound like a leaf blower.

1 Like

I will post a sound clip tomorrow :slight_smile:

Petrol Engine, 77.5k miles

You have kept that car well past it’s expiration date.