turbo oil leak

[llldks]

On a 1972 8V71TI, I've noticed oil dripping from my " sock " which covers the intake on the port turbo. Motor works fine otherwise. This is a symptom of ???

Larry
Seadation

[REBrueckner]

I had the same on my 1972 8V71TI's. It's a bit of oil mist from the crankcase....it's normal and is brought up to the sock via the crankcase breather tube to be burned in the engine. It also stains shirts instantaneously....You can try running your oil level maybe 1/2 way between low and full....I never tried that but it might help a bit.

I added RACOR CCV's to eliminate that muck (Similar to Walker Airseps) because supposedly it gums up turbo blades after a while but mine were clean when I checked them even before I added the CCV's. .

[MikeP]

FWIW re the ccv/airsep:

IMO the CCV does a much better job than the airsep.. Take a look at how the two systems function before deciding on a purchase. There was a lot of postings re the two here some years ago that is probably still available via search. The airsep design more easily pulls oil into the intake system than the CCV design. OTOH, installing airseps is easier since they essentially bolt on in place of the oem filters whereas the CCV is remote mounted.

[llldks]

I have 4 turbos and this is the only one dripping oil. Additionally, this is a definite change, I'm guessing maybe a quart every few hours. It is dripping down aft side of head and saturating diapers.

[Will]

If this problem is new, you may have a seal failing in that turbo and should probably have it checked out. It will only get worse with time.
Will

[Angela]

Hopefully some of the Detroit breathing/bleeding gurus will chime in on this, but I had learned (hopefully correctly!) from this forum that oil-leaking turbos are a disaster waiting to happen, as in "an oil fed turbo fire is one you just can't put out." That's the phrase that has always stuck in my mind from reading about engine stuff here. So, don't ignore that oil leak.

I remember doing a seatrial on a Hatt down in Marathon that had oil-leaking turbos...everyone was given a life jacket and a fire extinguisher. That was a while back...back before I fully understood the consequences.

[Genesis]

Oil coming from the intake sock can be from a couple of places. One of the more-common ones is the breather connection to the turbo's intake side. On an non-airsep (or Racor CCV) engine this is usually either caused by overfilled oil OR excessive crankcase pressure.

If the former the solution is simple, but if the latter you may have a fairly serious mechanical problem, albeit one that doesn't need INSTANT repair (it will only get worse though.)

It is also possible, however, that you have a center housing seal failure. The amount of oil you're reporting and that it's only one side of the engine that's doing it tends to argue for that rather than breather blow-by.

If the oil is coming from the CENTER SECTION or anywhere OTHER THAN the intake sock (e.g. the housing halves of the turbo itself, etc) and you have DRY (blanketed) turbos this is serious issue that must be attended to before the boat is run again. Check the blankets - if there's oil on them you have an extremely dangerous situation as those blankets are there to insulate the 1,000 degree exhaust housing. Needless to say that's plenty hot to light oil on fire. A turbo fire is a boat-destroying event and must be avoided. Oil-soaked blankets must be replaced and the leak stopped. In addition a severe oil leak down the intake can result in an oil-fed runaway (got airdoors?)

If the center section seals are leaking it will not only get worse but there's a decent chance the reason the seals are leaking (they're centrifugal/labirynth in design and essentially "fling" the oil away from the shaft penetration - it's a rather unique and ingenious way of doing it - and it works) may be center section shaft or housing damage. Should you have a wheel contact the housing while in operation the turbo is odds-on to grenade (they're spinning at ~100,000 RPM under load!) with severe results including a possible fire.

One thing to check before you tear the turbo off the boat is the drain coming out of the bottom going back to the block. That return MUST be unobstructed - any restriction at all in it will result in extreme oil leaks like you're seeing. There is usually a short hose section in there to isolate vibration and deterioration of that hose can result in a flap of material blocking oil return to the crankcase - that will cause the symptoms you're seeing.

This problem is one you need to isolate and fix. First check the inside surfaces of the blankets - if they're oily DO NOT run the engine under load (e.g. except to find and correct the cause of the problem) until you have new ones. Check the return oil line for obstructions (the easiest and cheapest potential cause.) If it's clear re-secure the return line, remove the breather connection and start the engine. If the breather is not puffing a scadload of oily air out the now-open breather hose it's odds on you have a center-section problem in that turbo and it requires rebuild or replacement.

The good news is that the little dry blanketed turbos are both reasonably easy to change and not all that expensive. Just make sure you fill the center housing with CLEAN oil before you start up after you put the new turbo on the boat so that center bearing does not start rotating while dry!