Anybody Had Problems With Reconditioned Turbos

[vern 0]

As title, My TT turbo is running 1 bar of boost, and the company reconditioning my turbo is having problems getting it reliable, ie 150miles between rebuilds . All that I have had done is a slightly larger compressor wheel, the symptoms of failure are oil everywhere, the report suggests the turbo is overboosting as worn thrust bearings on boost side?.

I have checked for boost leaks on intercooler and metal pipe under car, all connecting hoses are new silicon hoses. using the data logger on Emerald no overboost seen, but unlikely to see as turbo will produce boost to hide a leak, so turbo could be overboosting to produce any given boost.

Has anybody any expeience of turbos going very quickly after rebuilding, has anybody else changed to a bigger compressor wheel, any experiences, info to pass on.

Edited May 2, 2007 by vern

[TEKNOPUG 3]

Who is reconditioning your turbo, what work are they doing, how much are they charging. For reference, my standard TT turbo was reconditioned by TT themselves at a cost of £595 (by a previous owner I hasten to add). Also, it is highly recommended that a 360 thrust bearing be installed if you plan to run upto a bar for any length of time.

 

Hopefully Saveloy will be along soon to give you the benefit of his years of wisdom with TTs.

[vern 0]

Owen Developments are doing the work, they seem to think a 360 is not required as only running 1 bar, as Garrett use the same spec tubo as mine in a Fiat Coupe and they run 1.3 bar without any further mods. It has been totaly reconned new bearings seals etc. You would also hope the standard thrust bearings can withstand 1 bar of boost for longer than 150 miles, bit wary of changing to a 360 deg bearing without fixing problem as it will only mask issue till further on in time.

[pdd144c 0]

They rebuilt mine and I had no problems Vern.

 

If you have a boost leak it will cause the turbo to spin faster than normal, and this will cause very premature failure. Are you sure you have a decent oil feed to it? Not blocked or something silly?

[vern 0]

No oil problems, they were happy with that, no signs of oil starvation, or oil return. I have had the oil return pipe off to make sure oil comes out and it was ok. Surely if the turbo is over boosting to do that much damage in such a short time, you would hear it??. On the emerald the boost levels are rock steady.

Owen developments have a good reputation thats why I went with them they are being very helpful in trying to sort the problem, but are running out of ideas hence my post on here.

Also the 150ish miles 98% have been cruising etc, only minimal time on boost.

[TEKNOPUG 3]

What's the history of the turbo?

[vern 0]

The turbo was secondhand, but if fully rebuilt surely the history is imaterial??.

Owen dev were wondereing if it could be a mismatch of some sort between the upgraded compressor wheel and engine, but unlikely but we are clutching at straws on this.

[TEKNOPUG 3]

A mismatch in compressor wheel to engine size is more likely to show itself up as inefficencies in performance.

Where exactly is the oil leaking from? How does the turbo operate: down on power, nasty sounds, drop in boost/performance? Maybe there is a problem with the oil returning to the sump (or in the sump itself) and its causing a build up in the turbo which ultimately forces itself out past the seals? If there are no signs of damage to the turbo or seals after the oil leaks then I can only suggest that you get you self a pressure leak tester. I can point you in the right direction for reasonably priced ones. However, on a TT, the pipework is so simple that I would have though that it would be pretty easy to tell if there was a leak. Is there perhaps an incompatibility between the oil and the seals that you are using? After the turbo is rebuilt who is refitting it you or them? Have you tried reducing the boost level? Just some ideas.

[vern 0]

hard to pinpoint where the oil is coming from as it is everywhere, in the metal pipe under engine, in exhaust, running out of the downpipe join, all over the underside of the car. I think the oil is a by product of the thrust bearing going allowing to much movment of shaft dislodging the seals.

I have pressure tested the intercooler and metal boost pipe nothing major there.

The turbo performs well makes good power, boost levels nice and even, there is no noises but a there is a little whine after reving engine, this appeared on the second rebuild. They where happy with oil supply and return as bearings were ok.

I am fitting and removing the turbo myself. For most of the time I am running on the wastegate 7-9psi, the problems definately got worse when running on high boost 14.5 psi. I am running 5w 40 synthetic oil.

To overboost to the extent of it lasting 150 miles I would hope you would notice/hear some sort of leak?.

[TEKNOPUG 3]

Nothing jumps out and says "wrong". I would say that there is an inbalance on the the shaft which is exacerbated at higher boost but that would be to cast aspersions on your rebuilders. All I can suggest is see if you can get another turbo to try and therefore rule out all other possibilities. Out of interest, how much have you paid in rebuilds and trying to solve this problem so far?

[vern 0]

I spent £460 on first rebuild the second was done under warranty, it is at Owens as we speak so do not know if the 3 is going to cost anything. If it goes again it will be going somewhere else.

Every thing points to something done during the rebuilding process as that is all that is left, and I have no control over.

Anybody got a turbo I can borrow and possibly destroy?????.