I have been running my bus every two weeks or so to keep the bus alive. After reading so many scares of over fueling during idling I drove for ice cream last night with my son and a fellow school bus driver instead of just idling it. Round trip about 25 miles. When I run the bus and don't drive it I always use fast idle and haven't seen any adverse affects on the 8V71. I have read that idling is very bad "any thoughts"?
I find it kinda hard to believe that it can be as bad as I have read. Surely Greyhound idled these buses for extended times of say 15 or 30 minutes, if for no other reason than to keep the passengers comfortable. I have also read that you should idle just long enough to build air pressure and then drive. What about our pre trips and air brake checks? A proper air brake check will take eight or ten minutes. Plus I like to get out and look at the engine and exterior lights ect.. before the trip with it running.
It's not the idling that is bad, what is bad is to just idle the engine, no matter if at 650 or 900 rpm with out putting a load on it. Grayhound would idle the buses, but then be on their way. What happens is oil and residual fuel can collect at the bottom of the air box when idling. Then when you take off you notice a lot of smoke for the first mile or so, then it cleans up. This is what we're talking about. It is better to let the engine sit then to idle it ever couple of weeks. If you have the luxury of storing the bus in doors, then you can get away with not starting it except when you want to go somewhere. I store my bus indoors, and sometimes it goes months between starting. But every time I start it it acts as though it was started yesterday. The 8V-71 is a tough old bird-don't baby it and don't feel you have to start it often. Good Luck, TomC
If you don't put it under load for more than a few minutes the oil never gets up to the required temp to boil off moisture. The cycle of slightly warming it and then cooling can cause more moisture to build than not running it at all. Every cooling cycle sucks in a fresh load of air/moisture. Engine and tranny.
Good luck
Don 4107
Rick -
As opposed to your car, diesels cool when they idle, especially without any load on them.
Taking the bus for ice cream was far better for it than letting it sit and idle in the driveway for twenty minutes.
Fast idle while you do your pre-trip inspection won't hurt anything - but get in it and go somewhere when you're done, to bring everything up to normal operating temperatures and allow the condensation to boil off, like Don said. (BTW, there's a good, thorough generic pre-trip here:
http://www.busnut.com/bbs/messages/12262/16203.html?1167072614
Greyhound (and other revenue service companies) use the fast idle as necessary (and nowadays still legal) to keep the HVAC operating while stopped enroute. Between the huge A/C compressor and the big blower motors, there is a load put on the engine, not as great as running down the road, but more than just idling w/o anything turned on. But after their scheduled stop, they're back on the road, blowing out any build-up that may have occurred whilst parked at the terminal/depot/bus stop. That type of idling is fine.
What isn't good for the two-strokes is extended idling w/o any load on the engine, especially low idle.
FWIW & HTH. . .
;)
Roger that guys I will heed that advise. Thanks