Turbo Boost Leak - Damper Problem?

[Overdose]

Afternoon all,

I am chasing a boost leak and have the car in for a smoke test next week, but yesterday, I had time to do a bit of looking myself and have found oil mist blowing from between the turbo housing and damper.
I took the damper and hose off and pulled out a broken rubber seal which was a V-shape and a green o-ring. I can see that the green o-ring should probably be there, but have no idea about the other and the location for the green o-ring doesn't appear to have anything to back the ring up and stop it from blowing out.

Looking on eBay it seems that some of the dampers for sale have what looks like a plastic backup spacer that sandwiches the ring in place, this seems to be missing from mine and many of the others for sale on eBay, so I'm wondering if this might be a common failure point and it gets lot when the damper is removed.

The turbo has been replaced in the past and so this is the first place that I started looking and I'm sure that this is it.

The leak manifests as a 'hollow roaring' at the back of the engine and mpg drops when the turbo should be doing more work, so I'm fairly confident that I'm in the right area.

[Crasher]

What is the VIN?

[Overdose]

s-l1600-2.jpg
Spot the difference.s-l1600.jpg

It's TMBFL25J2B3193204.

The way the damper looked to me, I couldn't see any way that the damper would have worked satisfactorily, as the o-ring didn't have anything to keep it in its seat and I felt that it needed some sort of backup.

I also wonder if this part doesn't either get brittle or stuck on the turbo and then break when the damper is removed.

[Overdose]

I think I've answered my own question. The small scalloped out part of the damper is where the o-ring is pushed down to when it has no backup to keep it in place. The creates a small gap for the air to leak out of, but enough to cause at least 10mpg loss at higher cruise speeds.

[Crasher]

03L 131 111 G never had to replace one, £122.64

[Overdose]

Whoever replaced the turbo, has either broken the ring or it's been left on the old turbo and missed on installation.

What is interesting, is that most of the used items sold on eBay have this ring missing, so it must be a common issue when removing the damper. There would be no obvious sign of a problem until it was refitted.

[Crasher]

We did one last year, I think it was a CAYC, where a garage had fitted a used blower and it was gutless. Various garages gave up on it so we had it in and found the DPF WAS restricted so we took it off to send to DPF Clean team and decided to get Midland Turbo to do a rebuild of the turbo. When it was off we found a plastic bung in the damper and the cleaners reported melted plastic in the DPF… The bung had a VAG part number and ETKA showed this to be a floor pan bung (A4 from memory) so what the breakers had done is stuff these in both ends to prevent FOD but the fitter (I will refrain from calling them a mechanic) had missed them, this is why new/recon blowers come with big yellow bungs, usually on the outside of the connection.

[Overdose]

That damper has the backup ring missing too.