Turbocharger condition assesment help required
Turbo Mini Forums

As some of you know, I bought two GT1752 turbos on ebay not so long ago and firstgeneral look over indicated that they were in pretty good condition. Little play in the shaft on both, one better than the other.

Tonight I have been removing them from the manifolds and boost hoses, and generally giving them a good look over.

After removing the boost hoses on both, there seemed to be a fair amount of oil running out of the compressor housing. I decided to remove the turbine and compressor housings on the one that had a little more play and it would appear that it has been apart once before as the shaft, nut and compressor wheel have all been marked, there is signs of oil behind both compressor and turbine wheels, but as said before, the play on the shaft is only slight. I am happy that the play is within limits, but concerned that the seals may be leaking.

I am reluctant to pull the other turbo apart as it looks like its almost brand new. Compressor housing is still bright and clean, turbing housing has little rust as does the core, the water jacket, the nuts and bolts, and the turbine housing retaining plates. Less play in the shaft, and almost zero end float, but still has oil in the compressor housing.

Could it be just that they have been sat for so long?

i found a load of oil in my IC pipes last night too, well only the one connected the comp housing and a bit of oil sat in the comp housing. Mines a GT20 that was brand spanking new 400 miles tops ago, no massive play or anything int eh shaft either.

most of the cars in work seem to have oil in the intercooler pipes when i take the hoses off, seems to be the norm.

id fit the new looking one and see how it goes

no longer a series, but still 1.3 turbo.

Aren't the seals a bit like a piston ring in that thy seal properly when under pressure. So oil will leak through when everything is just sat there.

all you can do is stick one on.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

On my mates install the turbo is below the sump (not a mini) and he uses a pump to drain the turbo back to the sump. On the first install when the engine was off oil leaked back through the pump and out through the seals. But when running it was fine.

A non return valve sorted the problem. What I am saying is that they do pass some oil when there is no pressure on the seal. This was on a brand new GT17.

http://www.twin-turbo.co.uk
http://www.hillclimbandsprint.co.uk/default.asp

A man without a project is like a like a woman without a shopping list.

id hoike em apart colin , i dont have any oil in my pipes ,but the saab breather apparently does put some in , independant of turbo condition .
there should be absolutely no end float ,just a bit of up and down ,about half the gap between the blades and the wall .

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

id check out the piston clip grooves and the area is seats inside the housing, when i was doing re-conditioning alot had this problem and often found that replacing these solved the problem, as long as the grooze and seats are in good condition anyway.

you can get over sized piston clips i think but im not so sure

David.

I am tempted to give the 'newer' turbo a clean up and run that and see how it goes before I pull it apart.

The turbo I bought for £10 and used for mocking up is well FUBAR'd. Turbine housing cracked in three places, thrust bearing worn to alsmost 2/3 of its thickness, compressor wheel tips damaged and it was touching the compressor housing, the rear of the turbine wheel has been rubbing on the core housing which in turn has generated excess heat and cracked the turbine wheel in 5 places. The plain bearing and shaft journals looks good though

Time to get the DTi out, I managed to find the official SAAB axial play tollerence :) 0.036 - 0.091mm

Also, GT17 actuator factory setting is 0.32bar as it starts to move.

On another note, if you find it difficult to remove the turbine housing from the core, you might find that the housing is infact cracked. Two out of three cracked and the cracked ones were a bit of a bitch to remove.