The evidence of oil leakage past the oil seals in a turbo can be kind of a 'chicken and egg' thing: which came first, the turbo leakage or the engine problem?

In almost all cases, this type of leakage is traced to issues with the engine or installation itself.

Turbo seals are unusual in that even when in perfect condition, they are incapable of holding back oil in certain situations. These situations usually involve inadequate oil drain from turbo to engine, or excessive crankcase pressure. The first one is easy to check: make sure the turbo has a clear, unrestriceted oil drain. The second one results from either inadequate breather capacity, or damaged pistons/rings.

Wht do otherwise operable seals 'leak' under such conditions? In examining a turbo seal ring, you will note that two leakage paths exist: one through the ring end gap, and another around the ring itself, which is held stationary in the housing of the turbo while the groove it seats in on the shaft rotates at up to 140,000 RPM. Present this area with excessive oil or internal pressure, and oil will get past the seals.

For these reasons, even factory turbo cars always have a light sheen of oil present in their intake systems. It's a trace amount, not enough to cause smoke, but always evident.

We will be happy to counsel you on these aspects with your HRC turbo. Just call have your wrench call Tech Support if he has any questions. While it is unlikely that the turbo has a problem, the turbo can be inspected while out of the car if we deem necessary: it does carry a 12 month warranty, so you are covered.

Boost it!
Bill Hahn Jr.

Bill Hahn Jr.
98 RS Turbo: 10.87 @ 136 MPH
HRC Stage V with N20
Nation's Fastest Street FWD 2G DSM
www.turbosystem.com