'Thudding' under the bonnet of my E91 330D

'Thudding' under the bonnet of my E91 330D

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AlmostUseful

Original Poster:

3,282 posts

201 months

Monday 30th May 2016
quotequote all
It's never really bothered me much as I never knew how loud it was (good sound proofing see) but I was outside the car the other day when it was idling and there's a really rhythmic thudding going on somewhere - I've googled it but can't see anything likely/common and wonder if any of you had experienced similar.

I've never given it much mind because it's never given me a s off if it going wrong, and it's had 2 or 3 MOTs and services where I presume (rightly or wrongly) that if it was something major and an opportunity to get more business the garage would have mentioned it. But now I'm thinking of selling it I thought it might put a buyer off so figured it is time to sort it.

Any possible ideas? It will go to a garage eventually, but being a child of the Internet generation I have some ingrained need to have a load of strangers identify it! beer

AlmostUseful

Original Poster:

3,282 posts

201 months

Monday 30th May 2016
quotequote all
Just to assist you all, I'll try to post a YouTube clip or something with the engine idling so you can have a more educated stab, until then, just guess!!

It's quite bassy.

AlmostUseful

Original Poster:

3,282 posts

201 months

Monday 30th May 2016
quotequote all
Ha ha, I'm not much of a 'lol' kind of guy but it works perfectly there. Lol. (I can't believe I've done that I sort of public...)

Ok, over and above the clatter, there's a also a bass thud which sounds like I'm a bellend (well, I am, but for entirely different reasons!) with loud music when In fact my only crime is buying a car that's too small and runs on the juice of the devil! smile

AlmostUseful

Original Poster:

3,282 posts

201 months

Monday 30th May 2016
quotequote all
darrenw said:
My Dad has a 2005 525d and that does it, we've wondered about it a couple of times. He's had it five years and it has always been there, never got any worse or anything so we've just assumed it's nothing to worry about.
Whilst owning it I've had the exact same thought, I just don't expect a potential buyer to believe "yeah mate, been like it all through my 4 years of ownership, nothing to worry about" so I'd rather get it sorted.

Swoxy said:
Remove the engine cover.
Will that make the noise more obvious or make it go away?

AlmostUseful

Original Poster:

3,282 posts

201 months

Monday 30th May 2016
quotequote all
I'm not sure there's room for one in there, what with the engine cover and that strut brace at the back of the bay, maybe it's just a small one? How big is a small wildebeest?

AlmostUseful

Original Poster:

3,282 posts

201 months

Monday 30th May 2016
quotequote all
Righto, here's the video.
With the bonnet up it sounds more like air movement than any sort of impact.

The car runs fine, what part of thing could be losing air and not really be a problem?

Will try to get time to take the engine cover off tomorrow.

http://s222.photobucket.com/user/pimpingimp/media/...

AlmostUseful

Original Poster:

3,282 posts

201 months

Monday 30th May 2016
quotequote all
His rhythm is frigging insane, little bd must have a metronome in there. st, he might even have a proper gnome in there too!

AlmostUseful

Original Poster:

3,282 posts

201 months

Tuesday 31st May 2016
quotequote all
Duck quack is a very good comparison when up close with the bonnet up!

AlmostUseful

Original Poster:

3,282 posts

201 months

Tuesday 31st May 2016
quotequote all
Well I'm about 75k miles into my ownership now and I'm sure it didn't always makes that noise!