Hello chaps, hoping to pick some brains.

Just lately under hard acceleration I get a rattling sound from the engine bay. Seems to happen when the turbo kicks in ... almost as if the turbo itself is rattling I guess. Only thing is it sounds as if it's coming from underneath the centre of the engine. I can't recreate it with the car stood still either. Nor does it do it when the car is still and you just rev it hard .... guessing it's because the engine isn't under full load.

First noticed it when I started the car one night on a damp cold night. It sounded like a fan belt slipping. Revved it hard, heard the noise so stopped accelerating and let the engine drop back to idle .... at which point it ran lumpy, almost like a fuel blockage. It recovered and then ran alright, no noise under revving or anything. But it has happened since. Always when the engine is cold.

Was wondering if it could be alternator pulley .... but would like to ask if this sounds familiar to anyone?

Cheers

Edited 21 January, 201016 yr by allclownsareevi

Nope not the alternator pulley, i changed mine last year because i have the same rattle, but it is still there.

It obviously isn't something that is about to fail immediately though as mine has been doing it for the last 20K+ miles, without getting any better or worse.

Nope not the alternator pulley, i changed mine last year because i have the same rattle, but it is still there.

It obviously isn't something that is about to fail immediately though as mine has been doing it for the last 20K+ miles, without getting any better or worse.

I get something right at the point where it delivers gob loads of torque, really hard to describe the noise though - wouldn't describe it as a rattle - only does it since it was remapped

Hey chaps, thanks for the replies so far.

Hmmmm yeah it's kind of a rattle/clicking noise right at the point it delivers it's torque. My car is running around the 170 bhp mark ... odd thing is it's only done it lately.

Still no closer to figuring out what it is but if I ever do I'll post it up.

Righteo, might have some movement on this subject. I headed out to a mate's place last night who happens to be a VW Guru. As soon as I hit the motorway and gave it the beans to get to 70mph the car went into limp mode.

Long story short fault code threw up "turbo over pressure". Had a scan around the engine bay, nothing apparent. Then the VW Guru wanted to check the EGR valve because for months now my car has been idling lumpy. Cancelled out the EGR and hey presto it no longer ran lumpy. The weird side effect was the turbo noise has gone too. Seems it could have been that if the EGR was sticking open.

Ok all this happened just last night, so it's early days, but sure enough today, no rattling turbo noise. Will post back in a week or two but hopefully it's cleared it.

So out of curiosity, any of you guys fitted an EGR delete kit or checked the valve?