eddiewalker

I've been asking questions about the turbo on my 8.3 cummins engine in my 1989 Case dozer and want to thank you for your help so far.

I've made a new discovery that I think is causing all my problems.

I took off the drain line from the turbo and let it run after the engine was warmed up and oil was leaking all over the place out of the muffler and turbo.

Is it possible to have so much blowby that the oil wont drain back to the block?

Is there any solution to this besides an engine rebuild?

I have lots of power and have never rebuilt a diesel, just gas engines, and would really not have to if I can come up with some way of increasing my venting or getting the oil to drain back to the block.

Thank you,
Eddie

high country

you miggh not need to overhaul the engine, but instead the turbocharger

RCW

The Cummins 8.3 in the Case dozers uses a bushed turbo shaft that wears out the bushings and the seals from the normal vibration of the dozer being operated. If you have oil in the muffler, the problem nearly always the turbo bushings and seals. You can pop the intake side of the turbo off, shut off the engine and reach in and lift the spool. If you can wiggle it more than a few thousands, you need new bushings. That turbo is dirt cheap to have rebuilt by a turbo shop.

Unless you are pushing 10,000 hours on that engine, and have not kept it well maintained, I would not even think of any rebuilding of the engine itself. A $90 bushing and seal job on the turbo will probably solve all your problems.

There is one other problem that can turn up with both a 5.9 and the 8.3 that use the block mounted fuel transfer pump to charge the injection pump. If you oil is thinning and getting fuller as you run, check the inside seal of the fuel transfer pump. If fuel dumps to the engine side, it dilutes the oil and will create a lot of fumes that will create what looks like a huge amount of blowby. If the blowby gets severe enough it will force positive pressure on the crankcase, and if the downpipe vent gets dirty and plugged the pressure will block the turbo drain. If that happens oil will pump through to the muffler, and if left to do it enough you will start getting it on the intake side and the engine will develop a lope as it tries to burn vaporized engine oil. Rare, but I have seen it more than once where the draft tubes are allowed to plug with dirt.