Continuing oil leak

[viking1]

On my 89 MCI 102C3 with an 8V92. I have pressure washed the engines and chased down most of my oil leaks including installation of a container to collect the oil from the slobber valves. I have one oil leak remaining and I'm thinking it might be the most serious even though it's the smallest leak. There is oil leaking from the exchaust flange that mounts to the turbo. I pulled it all apart including removal of the turbo. When looking into the exchaust manifold on the right side its relative dry, the left side on the other hand is wet. So I have oil going into the exchaust on the left hand side of the motor? The bus runs very good, seems to make power but I am concerned that I might have a broken ring, bad valve or something. Any advice would be great. Next I'm gonna pull the exhaust manifold off to see which cylinder it's coming from. How do I do a compression check on a Detroit. And what should the compression be? Should I remove the head? Please please please help. Any one know of a good Detroit mechanic that can come to the house in Southern California?

[luvrbus]

Compression tests don't do much good on 8v92 just pull the air box covers and push on the rings with a pick or screw driver if they spring back they are good.
The got you is the 2 oil rings are not visible only way to check those is pull the head and remove the piston.
How much oil are you using ? most of the time when a oil ring is broken they will have a steady stream of oil coming from the air box drains.
Bad valve guides or seals they will smoke, just wet on 1 side it won't be the blower seals are you sure it's oil or fuel ? 

good luck   

[viking1]

Definitely oil.

I ran the hose from the slobber valve on that side into a soda can and running high idle for 10 min and driving less then 10 miles I had approx 1 inch of oil in the can.

[viking1]

The leak itself is not that bad, it drips from the flange connecting the left side exchaust to the turbo and it gets all over the top of the valve cover.

Not sure what to do next.😡

[azdieselman]

Definitely oil.

I ran the hose from the slobber valve on that side into a soda can and running high idle for 10 min and driving less then 10 miles I had approx 1 inch of oil in the can.

As Clifford asked, Could it be fuel?  It will mix with the soot in the exhaust and look like oil.

Does your oil level change?

[luvrbus]

Clean the check valves on each side of the engine,it should only drip oil at idle or shut down.A healthy 8v92 will use around a gal of oil every 1000 to 1500 miles some less.Oil from the drip tubes usually don't classify as a oil leak.If the oil consumption is a gal every 500 miles you may have problems check the level first on the dip stick the 8v92 bus engine holds around 7 gals over filled it will just sling it out

good luck   

[eagle19952]

Clean the check valves on each side of the engine,it should only drip oil at idle or shut down.A healthy 8v92 will use around a gal of oil every 1000 to 1500 miles some less.Oil from the drip tubes usually don't classify as a oil leak.If the oil consumption is a gal every 500 miles you may have problems check the level first on the dip stick the 8v92 bus engine holds around 7 gals over filled it will just sling it out

good luck   

1/2 to 3/4 gallon under won't hurt a thing.

[TomC]

When my 1980 KW was new, the 8V-92TA burned oil around 1200mi/gallon. Then at 500K mi I had it overhauled with updated "dryer" liners and the oil consumption went to 2200mi/gallon.
Your mistake was cleaning the engine. Pour a gallon or two of oil over the engine and call it a day! Good Luck, TomC

[Scott & Heather]

Honestly Viking, unless you have evidence of major oil consumption, trying to keep a leak free two stroke is a fulltime job. The only guys that I've ever known to be dedicated enough to keep a leak free two stroke was an eagle owner at the Arcadia rally who had a 6v92 you could do lick, and a lot of the boat owners with two strokes manage to keep them squeaky clean. But most of us just appreciate that the engine compartment will never ever rust out :-/


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[muldoonman]

Viking, how many miles on your bus??

[luvrbus]

Viking, you can use a infra/red or laser thermometer to check the cylinder, run the engine on fast idle and shoot the manifold at each of the 4 ports if the cylinder has a difference in the reading you could have a internal problem all 4 ports should read close to the same in temperature 

[viking1]

I used to fly DC3s,Martin 404s and Convairs, so I am used to a little oil. And I understand that the Detroit is like an old round engine in that way. We used to say, if it ain't leaking u need to add oil. But what concerns me is that it is dripping from the exhaust side of the turbo and the exhaust stack on the left is wet. I'm gone pull the exhaust of the left side today and see if I can figure out which cylinder it is. Before fixing a few big leaks, it was going through about a gallon every 300 miles. I have not been able to take it on a long haul since fixing the major leak. There was a crack in the cooper tubing that goes to the generator.Maybe I'll just clean it out real good with brake cleaner, add some marvel mystery oil, put it back together, slam my finger in the door and go drive it!

[viking1]

According to the data plate on the engine, it was new or remanufactured by Detroit in 2001. I bought the bus in 2007 and I was told from the seller that he believed the engine to have approx 85K miles on it at that time, but unable to verify it. Since then I'm sure I haven't put over 15-20K on it. So if the seller was right then it is a fairly low mileage Detroit.