| Author |
Message |
Michael Lewis (Puffbus)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, May 24, 2005 - 10:28 pm: | |
We ran the bus for a couple hours while checking out some electrical gremlins today. There was a small but steady light grey smoke coming continuously from the exhaust. This is a MCI9 with 6V92T. We had smoke before, but it cleared up on the freeway. We also have a oil leak at one of the two large clamps where the turbo manifold connects to the exhaust manifold.
We were told that this bus needed a turbo when we purchased it a year ago, but had a deisel mechanic check it out, he thought it was fine, and it was actually disconnected from the large pipe going down to the muffler. Otherwise, it runs well, is very quiet and cool and starts on the first click.
I'm sure I can find the clamp locally at a truck parts house, but am now wondering again about the turbo. How can this be checked out, and what is the group experience with this?
Thanks for your help.
Michael |
David Hartley (Drdave)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 25, 2005 - 6:34 am: | |
If the turbo has an internal oil leak you should have it replaced or repaired as soon as possible.
If the turbo is disconnected it will seriously cause poor performance and potentially other problems. The other possibility is what is called "slobber" where oil and unburnt fuel is leaking through the exhaust system and will seep out of the exhaust and turbo clamp areas. If this is the case then you probably need an overhaul of the whole engine. Oil may be getting past the piston rings or you may have a bad cylinder liner that is warped. Many factors can cause internal oil leaks in a detroit, There are several o-rings in the air paths and if any are leaking the engine will suck that oil through and burn or slobber it out the exhaust.
Oil can come from other places such as the Turbo, or any number of seals in the roots blower. I had a similiar problem on my RTS and the roots blower drive seals self destructed and then took out the whole engine as the blower drive disintegrated. Turns out I also had a couple of bad rings and warped cylinder liner also. Lunched that engine. Had to replace the whole thing.
Are you getting a lot of oil from the drip tubes under the coach? If so it's time to rebuild. |
Michael Lewis (Puffbus)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 25, 2005 - 11:44 am: | |
David,
We get very little drip from the slobber tubes. In fact, we have almost no oil leaks anywhere else, but at the clamp mentioned above. Somehow, I still don't believe that this turbo is bad, as it spins freely with no end play or slop. I suppose Detroit could bench test it, no?
Michael |
bowlingshoegiverouter
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 25, 2005 - 1:22 pm: | |
bearings might be o.k. seals might be out....I'd say you need a new turbo |
David Hartley (Drdave)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, May 25, 2005 - 2:17 pm: | |
It could be a seal, Dry starts after sitting a while can be harder on the seals than the bearings so they might feel tight but still be out of tolerance enough to damage a seal if it just didn't break down from age and heat.
Any truck shop should be able to replace the bearings and seals for you if you take it to them.
Otherwise I have seen rebuilt/used exchange detroit turbos on eBay for about $600, I think there's one on there today. For a 6V92 |
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