1995 850 Turbocharger oil leak

roy1956 · Post by **roy1956** » 20 Dec 2014, 10:16

I have been noticing oil on the garage floor where I park my 850 Turbo Wagon every night. It is not much, but I find it annoying. What I see when I get under the car is a drop of oil hanging on the low point of the turbo compressor side. Also, I notice a very slight smell of burning oil when I come to a stop light. I am losing oil from the crankcase at the rate of a quart in 1,800 miles. I am sure some of that is getting past the rings as the car has 237,000 miles but the turbo leak is bothering me. Just to be clear, I have already done the turbo oil drain line fix where you add an extra gasket. That is fine. When I remove the air inlet or exhaust tubes from the turbo, there is a buildup of oil in the air passages which I don't feel is normal. The turbo is original and runs fine, does not smoke or make any noise. I am thinking it is just a worn seal and I was getting ready to do a turbo rebuild but I have been reading about turbo rebuild disasters and now I am a little cautious. I can't afford a new or rebuilt turbo at this point and I can't afford to have the car down for an extended time. My turbo has none of the issues which typically indicate that a turbo rebuild is needed. Leaking oil is not a symptom that seems to indicate that a rebuild is required. So now I am debating whether to just live with the leak or try to correct a problem that may not be correctable. Perhaps there is a certain amount of oil leak that is "acceptable".

If anyone out there has done a DIY turbo rebuild please share your experience! I would just like to get an idea of what I am getting into and what my chances of fixing the leak are. The last thing I need at this point is to take a perfectly running car and disable it by trying to fix a turbo oil leak that may be "normal". Thanks for any feedback!

Post by **rspi** » 20 Dec 2014, 10:48

Ouch! I thought that was normal???

You likely have a rear cam seal leak. Check that.

Welcome to the forum.

Post by **Ozark Lee** » 20 Dec 2014, 10:55

The oil under the turbo may not be from the turbo at all, that is just a convenient point for it collect and form a drop. An oil film on the lines from the turbo is pretty typical and isn't really anything to get overly concerned about.

Has the PCV system been serviced on the car? A clogged PCV will cause all kinds of oil leaks and ultimately it starts blowing cam seals or the dreaded rear main seal. A quick test for the PCV is to pull out the dipstick while the engine is running and look for vapors from the dipstick tube. You can also put a small balloon over the tube or a rubber glove. If they inflate the PCV is clogged.

Another common oil leak is the oil return line gasket and O ring from the turbo. It is a cheap repair that only mid level on the PITA scale. We have excellent writeups in the repair database for both issues.

Rebuilding the turbo isn't totally terrible but there are a couple of snap rings that are huge and they are difficult to deal with. There are a couple of "gotchas" like the threads on the compressor being a left hand thread and it is difficult to scribe the shaft and the compressor to get it back aligned as it was before. The alignment is fairly important as it needs to be balanced. If you rebuild do yourself a favor and buy the actual Mitsubishi kit and not one of the cheap $30 ebay kits.

I wouldn't jump straight to a rebuild though until you remove the intake snorkel and check the turbo for end play. Ideally there shouldn't be any but in reality there will always be slight end play (.015 to .020 is fairly average). When it gets to 1/8" or so you are in trouble. I rebuilt one a couple of years ago that had that much and it was getting close to the point where it was going to start scraping. You should also look for slop vertically on the bearings. There should be no perceptible slop there.

...Lee

roy1956 · Post by **roy1956** » 22 Dec 2014, 09:35

Hi Lee
Thanks for the great reply! Here are the answers to your questions...
Yes, I did a complete PCV service a year ago, bought a kit from IPD and changed everything out so that is working fine now.

I did the turbo oil return drain line a while back and that is clear as well.

You mentioned pulling off the intake hose and checking the end play of the turbo shaft. I have pulled off the hose and the one thing that is remarkable is how much oil is accumulated at the fittings. I suspect the oil that is dripping is coming from the bottom of the intake tube which is plastic. What is most annoying to me, aside that I am losing oil from the crankcase faster than I think I should, is that I get a few drops of oil on the garage floor every time I park and the faint whiff of burnt oil smell when I am at a stop light coming from the cowl vent. I have checked the cam seal and that looks good. I also recently changed the transmission front seal around the torque converter and while I had it apart I did the rear main seal on the engine. No problems there with leakage.

So back to the turbo. If the shaft play is within limits, and I am assuming it is, I am wondering if there is an internal rubber O-ring that has gotten hard or coked up which is why I am leaking oil. If the "seal" of the turbo is simply from the tightness of the bushings with the shaft, then changing the bushings should cure that. But if it is an O-ring that creates the seal to keep from losing oil, then I would need to change that as well. Something isn't right though as there is simply too much oil on the intake side. I am on a mission to get this oil leakage stopped, if you can't tell, lol. Despite the 237,000 miles it has, the engine runs great and has good compression so I think I have a few more years of driving it (I bought it new in 1995). I have been religious about my oil changes and using good quality oil and filters. I just need to get these annoying leaks stopped.

Thanks again for the comments!

Post by **Ozark Lee** » 22 Dec 2014, 16:03

The turbo seals can fail while the bearings and the thrust plate remain OK. If you do have a lot of oil on the intake snorkel or in the charged air pipes then turbo seals may well be the issue. The bearings getting sloppy are usually the first thing to go on the turbo but the seals can just up and fail. Oil pooled at the intake snorkel usually isn't the turbo but excessive oil through the PTC nipple. When the cold side seal fails it tends to put more oil into the charged air intercooler lines than it does on the intake snorkel pipe.

SOP is to rebuild the turbo, including new bearings and a new thrust plate along with the seals when anything related to the turbo fails.

...Lee