Mercedes A class A220 petrol - Mercedes A220 w177 tapping noise on cold start

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Sat 5 Mar 2022 11:55
Mercedes A class A220 petrol - Mercedes A220 w177 tapping noise on cold start - yrhengastan62

Hi all, I bought a used Mercedes A class from a main dealer recently. It's lovely, I really like the car. Only one thing is that on a cold start, after 2 minutes idle I get a tapping noise from the engine that increases in loudness until it's clear to hear. However, a short trip of 3-5 miles to warm up and it goes away. I'm not sure I should be worried or not as all else is.fine. I've contacted the dealer to seek reassurance as I'm concerned this may lead to some longer term wear or failure. It may be normal, I just don't know. Has anyone had a similar experience and was it resolved in any way ? At the moment it's more embarrassing than anything else. It's a a 2019 premium.model, originally a demonstrator and then locally owned. 12000 miles , full MB history and serviced before collection. Unless I get reassurance I might reject which would be a shame. Thanks for the help.

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Sat 5 Mar 2022 13:16
Mercedes A class A220 petrol - Mercedes A220 w177 tapping noise on cold start - elekie&a/c doctor
Most modern petrol engines now use a high pressure injection system that very often sound noisy from cold . However, this doesn’t sound right in your case . I would certainly return it to the dealer for an appraisal.
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Sat 5 Mar 2022 14:12
Mercedes A class A220 petrol - Mercedes A220 w177 tapping noise on cold start - yrhengastan62

Thanks for the tip, I made a short video of the noise at.....

youtu.be/dxLhRziR8h8

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Sat 5 Mar 2022 14:41
Mercedes A class A220 petrol - Mercedes A220 w177 tapping noise on cold start - elekie&a/c doctor
There’s a lot of clatter going on there that doesn’t sound right to me . My neighbour has an 30 year old Vauxhall cavalier which runs like a sewing machine at idle .,
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Sat 5 Mar 2022 15:04
Mercedes A class A220 petrol - Mercedes A220 w177 tapping noise on cold start - RT

It's unlikely given the young age and low mileage - but your description sounds like a badly worn engine that's been filled with thicker than normal oil to mask the problem - or maybe been serviced with the wrong grade of oil.

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Sun 6 Mar 2022 10:13
Mercedes A class A220 petrol - Mercedes A220 w177 tapping noise on cold start - John F

It sounds dreadful. I would reject it. It can't possibly be 'worn' at a mere 12,000 miles. Try listening to a similar engine at the dealers. I remember a past Audi of mine used to occasionally sound tappety at cold starts - oil drainage from hydraulic valves IIRC - but this sounds worse.

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