Turbo screech

T

TGD

Member
Joined
Apr 5, 2017
Location
Essex,UK
TDI
2004 A3 1.9 TDI BKC
Hi,got a 2004 A3 1.9 TDI with the BKC engine.
It drives fine but has a really loud high pitched screech at just over idle,starts as soon as i let go of the clutch and sets off,prob from 11-1200 rpm.Put my foot down and give it a bit more revs the noise goes away.
Drove it without the serpentine belt,no difference.
Drove it without the "charge" pipe in to the EGR removed,no difference.
Then i took off the the vacuum hose to the VNT,still turbo pressure and no EML on,noise gone.
Checked the VNT arm,moves freely.
Took exhaust pipe off the turbo,no play in/out or side to side,spins freely.
The car doesn't smoke,doesn't use oil and boosts fine.
Any ideas of what i need to look closer at ?
Dead turbo ?
Dead vnt ?
 
Last edited:
T

TGD

Member
Joined
Apr 5, 2017
Location
Essex,UK
TDI
2004 A3 1.9 TDI BKC
Only on the exhaust side,not the intake side.Taking the inlet pipe off on monday to have a look at the impeller and will probably take the turbo off to inspect it a bit closer.
 
T

TGD

Member
Joined
Apr 5, 2017
Location
Essex,UK
TDI
2004 A3 1.9 TDI BKC
Right,took the turbo off the car today,no sign of any impeller damage on intake or exhaust side.No sign of oil inside the intake side,clean as a whistle.
Really confused about this,any suggestions as what to try before buying a new turbo ?
 
C

Carlos_TJ

Veteran Member
Joined
Aug 3, 2014
Location
Tijuana Mexico
TDI
2009 Bora (BXE PD)
How many miles/kilometers on the turbo?
My own tdi turbo started developing a faint "ambulance siren" sound when engine is cold at 1000rpms that disappears at around 1500 rpms, then the regular turbo whistle is heard.
I have an ocasional limp mode that i cant track.
Car drives ok.
From what i have read my symptoms are of a early worn out turbo. Play is not bad. Oil consumption is ok.
 
T

TGD

Member
Joined
Apr 5, 2017
Location
Essex,UK
TDI
2004 A3 1.9 TDI BKC
The car has done 125.000 miles or about 200.000km,i have no oil consumption,smoke or boost problems.Car drives spot on,but screeches really loud at low revs unless vnt is disabled.
At this mileage i have no problem fitting a new turbo if that's the problem,but i'm just puzzled as to why disabling the vnt stops the screech ?
 
Tdijarhead

Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Wife’s car, 2005 Golf TDI Mine, all 5 spds
I changed out my turbo about a year ago and when I put it all back together the car started right up but as soon as I touched the accelerator I would get a screech. I had forgotten to tighten two of the egr pipe bolts. The little metal gasket vibrates as air moves across it at high speed.

Have you had the egr system apart for some reason?
 
T

TGD

Member
Joined
Apr 5, 2017
Location
Essex,UK
TDI
2004 A3 1.9 TDI BKC
I do apologize,i forgot to mention,the egr has been blanked off and the cooler bypassed.
 
Tdijarhead

Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Wife’s car, 2005 Golf TDI Mine, all 5 spds
TGD said:
I do apologize,i forgot to mention,the egr has been blanked off and the cooler bypassed.
Click to expand...

Double check all those bolts and make sure they’re tight noise could still happen if something is loose.
 
T

TGD

Member
Joined
Apr 5, 2017
Location
Essex,UK
TDI
2004 A3 1.9 TDI BKC
Right,a little (very embarrassing) update.
Had a friend holding the revs at 2000rpm where the screech was consistent and started feeling for air leaks around the exhaust manifold.Sure enough,it was blowing from the egr delete plate i had fitted to the exhaust manifold.Took the plate off and put it on a piece of glass,it was banana shaped...
Fitted it again with a new paper gasket,but the other way round so it "bowed" down in the middle,hoping the two "high" ends would be pulled down by the nuts (no,nothing naughty here) and sure enough,no more blowing and no more screeching.
To quote Homer "Feeling stupid ? I know i am"...
Thank you sooooo much for the suggestions guys,can't believe i overlooked this simple solution.
Well as soon as the courier gets here i will at least have a spare turbo...
Thanks again guys :)
 
Tdijarhead

Tdijarhead

Top Post Dawg
Joined
Nov 10, 2013
Location
Lawrenceville PA
TDI
2003 TDI Jetta Daughters Car, 2001 TDI Beetle, Wife’s car, 2005 Golf TDI Mine, all 5 spds
Actually it takes a man to "man up" , we've all done stupid stuff and forgotten things we shouldn't have. Glad you found the problem and corrected it.
 
R

RV9Factory

Well-known member
Joined
Sep 17, 2011
Location
Dallas
TDI
2006 Jetta
TGD said:
Right,a little (very embarrassing) update.
Had a friend holding the revs at 2000rpm where the screech was consistent and started feeling for air leaks around the exhaust manifold.Sure enough,it was blowing from the egr delete plate i had fitted to the exhaust manifold.Took the plate off and put it on a piece of glass,it was banana shaped...
Fitted it again with a new paper gasket,but the other way round so it "bowed" down in the middle,hoping the two "high" ends would be pulled down by the nuts (no,nothing naughty here) and sure enough,no more blowing and no more screeching.
To quote Homer "Feeling stupid ? I know i am"...
Thank you sooooo much for the suggestions guys,can't believe i overlooked this simple solution.
Well as soon as the courier gets here i will at least have a spare turbo...
Thanks again guys :)
Click to expand...
TGD you describe a screech. Was it like a whistle?
 
T

TGD

Member
Joined
Apr 5, 2017
Location
Essex,UK
TDI
2004 A3 1.9 TDI BKC
Tdijarhead,absolutely,that was a little reminder to myself,never forget to check the easy things first.
RV9Factory,no it was a high pitched really loud metallic screech,almost like what you sometimes get when drilling in metal.Hence the reason why i foolishly didn't spend much time at first looking at air leaks.
 
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