| Author | Message | ||
| Michael Lewis (Puffbus)
Rating: N/A |
After reading several good posts from the board and a few calls to turbo "experts" we have decided to replace our turbo (MCI 6V92). The thought of a runaway is terrifying, especially when we really don't know how many hours/miles are on the engine. After reading a couple threads on engine oil, I am also wondering if this would not be a good time for an oil change, to assure that we are actually running a good 40WT in this engine. The oil was changed prior to our purchase, but the bus has been sitting almost a year with only occasional startups. It also has not been brought up to full engine temps with a good freeway run. I have seen more than one post describing a change to straight 40WT fixing most of the oil leaks on this notoriously dirty engine. However, I'm not fond of seeing actual droplets being squirted on my engine doors after an hour of idling. BTW, I also found an excellent site which explains more than you ever want to know about turbos. The graphics are worth the visit: http://www.turbodriven.com/en/company/index.asp Michael | ||
| Jim Bob Rating: N/A |
Michael, would you let a two cycle outboard motor or a chain saw idle for an hour? (Assuming they would stay running that long.) Most people would not because they "load up" & stall. Well the two cycle Detroit also loads up, but it won't stall. But it WILL slobber from the air box drains and maybe the exhaust. This is because fuel & oil will accumulate in the intake, just outside of the cylinder ports when the engine is idled. You should start the engine and idle just long enough to build up air pressure before driving the bus. Use of the fast idle system can help if you need to idle for more than a couple of minutes. As soon as you are able, take your bus out for a freeway drive of at least one hour. (more is better) When you pull back in, you will notice it is running more smoothly, higher idle speed & clean exhaust. It will "sound happy"! If it is still spitting oil drops on the rear of the bus, look into fitting a catch tank & check valves on the air box drains. Walker Engineering offers one. Sometimes, little seal leaks on engine, transmission, rear axles, etc will cause oil on the back too. | ||
| David Hartley (Drdave)
Rating: N/A |
Detroit 2-Strokes love to bang against the governor at max load all day long. Idling and only starting one occasionally will cause condensation inside the engine and "loading up" of the valves and exhaust system of a lot of gunky dirty unburned fuel and sludge from oil that gets past the rings until the engine is fully warmed up and "blown-out". If it's gonna sit at least prepare it for that use. Also I use a 1 gallon jug of Lucas Oil additive when I change oil. This helps prevent dry starts and improves the oils ability to coat the engine parts. Get out and drive that thing, It expects it and deserves it. Plus you probably could use the excercise too...  | ||
| John that newguy Rating: N/A |
Ditto past remarks... and one more? Expect oil "droplets", "squirts", and any other configuration of oil deposits if you own a two stroke. It's like a Harley: it's the mystique; the kharma; the pride in the puddle. | ||
| tony bare Rating: N/A |
I guess that a bus with a DD engine is like my Harley Davidson. It don't leak oil- it just marks its spot. | ||
| john w. roan (Chessie4905)
Rating: N/A |
If it has to idle at home that much without driving; warm it up with a block heater and leave it on while it is idling. Will help to keep the temp up; Is not a substitute for a good spin down the road, but better than nothing | ||
| Michael Lewis (Puffbus)
Rating: N/A |
Good points, all, and well received. The reason for running the bus at idle for an extended period was one of chasing down some electrical problems and getting the heater working. There's no way I know to operate the heater fan and check the water lines without running the bus. We also have the steering column out for trim work in the drivers compartment. Our goal this week is to finish the trim and carpet in the front and have the bus drivable for a few "test" runs prior to the Bus N USA event in July. Hopefully, any mechanical issues will show up on a few 1-2 hour runs. It's still up in the air if we are actually going to bring the bus or stay in a hotel or with friends. But we'll be there..! Michael |