Golf gti mk6 suspected dying turbo - or not?

Golf gti mk6 suspected dying turbo - or not?

Author
Discussion

JS1902

Original Poster:

115 posts

44 months

Sunday 25th September 2022
quotequote all
Been chasing a whistle/whine upon hard acceleration on my mk6 gti for the past month or two. The car has also started to consume more oil in this time frame. I’ve changed a leaky breather pipe and diverter/recirc valve to no avail.

A supposed vw indy has diagnosed it as new turbo needed based on the noise and they found oil leaking from the turbo itself. Compression test carried out was fine and all cylinders within tolerance. No oil deposits on spark plugs either.

My original thought was that the whistle was a boost leak as it only occurs 2-4000rpm and doesn’t pull as hard (but fine in upper rev range). Also would a failing turbo (oil seals) show up as smoke from exhausts and not an actual external leak?

Mileage is 130,000 so could well be the turbo. No engine lights on.

stevieturbo

17,535 posts

254 months

Sunday 25th September 2022
quotequote all
oil could simply be due to the PCV system


Noise could be the turbo...or a leak. Leaks are easy to test for.

And even a visual/feel on the compressor wheel would give some indication of how the turbo is.

rottenegg

811 posts

70 months

Friday 7th October 2022
quotequote all
Probably just a boost leak at that mileage. Usually the O rings in the bayonet joints. There are a few to check/replace throughout the boost pipe path.

Mine got replaced at 165K, but it still boosted OK with no smoke or noises. I just spotted some brass coloured dust in the oil pan during an oil change, and sure enough, there was a good half mill or so axial play in the turbo shaft. It wasn't far off compressor wheel rubbing housing fun and games. When that happens, you really WILL have a noise to diagnose. It's a very loud screech of death.

If you have VAG-COM, check the actual and requested boost pressure measuring blocks, and the N75 wastegate duty %.

JS1902

Original Poster:

115 posts

44 months

Friday 21st October 2022
quotequote all

rottenegg said:
Probably just a boost leak at that mileage. Usually the O rings in the bayonet joints. There are a few to check/replace throughout the boost pipe path.

Mine got replaced at 165K, but it still boosted OK with no smoke or noises. I just spotted some brass coloured dust in the oil pan during an oil change, and sure enough, there was a good half mill or so axial play in the turbo shaft. It wasn't far off compressor wheel rubbing housing fun and games. When that happens, you really WILL have a noise to diagnose. It's a very loud screech of death.

If you have VAG-COM, check the actual and requested boost pressure measuring blocks, and the N75 wastegate duty %.
If the actual boost was less than requested, wouldn't ECU flag this up resulting in EML on?

Is it the o-rings in the air intake system from airbox to turbo or turbo-intercooler hoses?