Screeching from Engine at mid revs

ukguy

Veteran Member
Joined
Jul 27, 2004
Location
Manchester, UK
TDI
VW Golf MK6 1.6 TDI Bluemotion Match
Hi all,

I am having an issue with the engine in my VW Golf MK5 1.9TDI (engine BKC with 111K miles) which is driving me mad at the moment.

Basically, only when there is no or little load on the engine (mostly when decelerating but has been replicated at standstill) I hear a rather loud screeching noise coming from the front end, only between 2300rpm and around about 1700rpm , to the point where other motorists can hear it and look over! It sounds like a metal on metal sound. It doesn't matter whether the car is in gear or not. It also doesn't matter if I am doing 20mph or 70mph, the noise can be the same. The best way to describe it is like a constantly slipping belt screech or the noise you hear when a stone is stuck in a brake pad rubbing against the disc or when you're running the brakes with no brake liner left. It's definitely neither of these things though after some investigation...

The serpentine belt got swapped out, that didn't cure the problem. Then I thought something else running off the belt might be causing it (AC/Alternator) so I removed the belt and went for a short drive....the noise remained so that is now ruled out.

The noise can happen at any speed, be it on the motorway or pulling up to traffic lights, it is not speed dependent but instead engine revs dependant (i.e I can coast on the road to a standstill and everything is quiet).

I do get the car going into limp mode occasionally with the following code showing up in VCDS, only after the engine has been worked hard:

16618 - Boost Pressure Regulation: Limit Exceeded (Overboost Condition)

I can only attribute this to possible soot in the turbo but not so sure as the VNT lever moves relatively easy and cycles in basic settings 11 in VCDS. I have checked vacuum lines and they look OK. The noise is too much like 'metal on metal' anyway... The exhaust emissions seem fine with no significant smoke at the back.

So now I am stumped. I'd rather not have a new turbo fitted only to find out that it wasn't that causing the screeching. I would have thought if it was the turbo it would be doing it on acceleration or when increasing engine revs, but the symptoms are vice versa.

If anything has had something similar happen or knows what it could be, I'd be very interested in hearing from you!

Thank you.
 
Last edited:

ukguy

Veteran Member
Joined
Jul 27, 2004
Location
Manchester, UK
TDI
VW Golf MK6 1.6 TDI Bluemotion Match
I have uploaded a video showing the noise on deceleration.
http://www.youtube.com/watch?v=GpkKlfgMDbw
The car was stationary at the time in neutral and the accelerator was revved. It doesn't make any difference if the car is moving and decelerating, the same noise occurs when there is little/light load on the engine at around 1500-2200rpm. It's harder to hear though because of other road noise etc in a video... But still very annoying and noticeable.
Could this still be spigot bearing or release bearing alone based on my symptoms? Thanks.
 
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