CM871 turbo premature bearing failure

[Rawze]

some things to know...

== There SHOULD BE up to about 0.045" side-side play in a VGT turbo if you press on the shaft hard to one side and the other.

VGT turbo (actually any holset turbo) ... WILL LEAK OIL out of its face if there is ANY crank case fumes buildup ... I.E.> high enigne blo-by, or even slightly clogged crank case filter. They typically are NOT a perfect seal.

Air inlet restrictions and a lot of idling can cause turbo to bleed oil too. - All normal.

Turbo shafts do NOT use rubber face seals. They use turkon-style seals that are a loose fit. This is so the shaft can spin 120,000+ rpm and not get cut or get excessive wear by the seal. There is also not any oil pressure behind the seal.. it is leak oil from the crank case. - Hence, Any crank case pressure buildup (which there should be none) will make oil pressure at the turbo face seal causing it to bleed.


You say your CC filter is is drilled out... when is the last time you took it apart and verified it was not completely rotten in there and can still breahthe really good?.

when is the last time you verified that the tube after it is not getting clogged with shmoo or dirt?.

Also,... What is the max boost you see in a hard pull / what positions is it going to?.


Crappy chicago after-garbage turbo or not ...

I.E.> It is NOT normal for multiple turbos to become leaky like that unless you have blo-by issues or oil flow problems.

I.E.> it is ALSO VERY NORMAL to have side-play in the turbine on inspection (up to 0.045") which can be felt.

Could it have been that your first replacement was perfectly fine and you replaced it again not knowing any better due to other circumstances?.

just some thoughts.