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Leave Bus Running
I am curious about others habits on a few things:
When on a trip and making a short stop for fuel, food, or other, do you leave your bus running or shut it down? What about idle? I have been told to reduce unburnt fuel, I should always leave on fast idle when sitting. What do others do? Another habit question is how long do you allow your bus to sit without being started, driven and exercised? I don’t like to ever leave it for more than 3 weeks, two if possible. What do others do? Last question is about the breather tube. Does anyone else have a series 60 that “breathes heavy” (some smoke puffing out breather tube after extended running. I have checked with Detroit on this and they have told me some engines will “breathe heavy and if I am not seeing oil usage all should be ok. I have also checked for pressure on the oil fill tube and that is not an issue. Has anyone else experienced this? Just some curiosity questions.
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12 Replies
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The idle time on my coach is dictated by the situation. If I am stopping just to use the toilet it is likely it will be no more than a 2 or 3 minutes stop so I just leave it running on high idle.
If I am stopping for 10 or 15 minutes I turn it off. If I need air conditioning I will run the generator.
We often have the coach unused during the summer months so I tend to never start the engine until we begin traveling again. I am of the opinion that if you start a coach after a period of storage you should drive it long enough to get everything up to operating temperature which usually is about 50 miles. Moisture is created on a cold start up so it is important to get the engine and oil hot enough to evaporate that moisture.
Usually when a lot of oil or smoke comes from the breather it is an indication of blowby past the rings in the engine. As our engines age I suspect that can be expected, but I would be surprised if an engine with less than several hundred thousand miles would do that. I don’t think that is an indication of a bad engine, just one with “experience”.
I would be concerned if the engine was low mileage however.
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Anytime mine idles it’s on high idle except when cold on start up. The only time I let it run is if it’s hot and the A/C is running while fueling, now that fueling for PC folks is only 15 minutes (except for Gil, he has to make two trips to the fuel desk, get in line with the shower folks and wait his turn). Anymore than say 15 mnutes I shut it down.
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If I am stopping for and hour or so then I leave it running. I was told by the entertainer drivers I know (They were the only source I had before PC) that is standard procedure. They say starting you engine is the cruelest thing you can do to it so leave it running. I have been told by others since, that it makes no difference.
I always leave it on High Idle. I switch to Low Idle for about a minute before I shut down.
I usually travel once a week but when I sit for a few weeks I will usually start it once a week. But if you start it you need to get it up to normal operating temps or you may do more harm than good.
Davy
1999 XLV X-6872, liberty #440 -
I generally leave mine running on low idle because there seems to be more vibration at high idle.
Mine was/is a “heavy breather”. Purchased at 6 years of age with 47000 miles. It has not used oil, now at about 185K. I installed a Donaldson PCV vented to the outside.
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Paul, I had that issue with smoke puffing from the breather tube and found that changing the filter on the crankcase breather did the trick. The filter looks sorta like a brillo pad, and I think it that if it gets oily, smoke will start to puff out the bottom of the tube when the engine gets hot and heats up the filter. On mine it is really hard to get at so I had MCI change it during my last oil change.
As to the idle, like others I will let it run on high idle if stopping for 10 mins. or less, but otherwise shut down. Always use high idle. There is a reason they gave us that switch, and you will see that the oil pressure is higher on high idle, which should be better all around.
Long idle times on high idle are common on tour busses, which need to idle to keep the A/C running. While probably not too harmful, it’s also not helpful and does use a lot of fuel. The MCI conversion shells share more DNA with their tour bus cousins than do Prevosts, and mine retains the driver monitor system which records and nags about such things as idle time, hard braking incidents, time driven off cruise control, ect. Idle time is the first item on the menu, so I assume fleet operators find it most important — probably for the fuel use issue alone.
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Paul & Lisa;
The situation dictates my idle time. If I have been waitng a few minutes in line to buy fuel behind a poor sole who does not use the PC Fuel Discount Program, then I will shut off the engine while I refuel.
If I drive right up to the pump, the engine stays on. Restroom breaks and short naps, the engine stays on. Normally I use high idle.
However, if I am going to shut down the engine, I follow Robert Hits’ advice. Robert is the Prevost Trainer who spoke at several PC Rally seminars. He told us to idle for 2-3 minutes on low idle prior to shut down in order to cool off the turbo.
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By the way, I often have to leave mine idling for hours to use the road a/c when it’s too hot for the cruise airs to function. As I previously mentioned, I use low idle due to vibration and a/c performance and battery maintenance is adequate on low idle. I change oil every 10,000 road miles and have oil analysis done each time…no issues.
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I was told not to ever idle for more than a few minutes on low idle. I asked Prevost about it just 2 weeks ago, they said you could idle all day long with the bus air going on HIGH idle, to keep the oil pressure up, and the turbo spinning at a higher rate. The only thing it hurts is your pocket book for the fuel. I don’t worry about that, I’d rather be cool.
Bryan, where is that crankcase filter located? Mine will puff after its hot, but not when it’s cold. No oil consumption.
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Jerry, the breather filter is located up on the very top of the engine and is barely visible from the rear doors of my bus. They had to access it from inside the bedroom closet. The part was about $6 and labor… much more.
Mine did not smoke constantly, but would puff some light colored smoke like a cigar smoker blowing a smoke ring every few seconds. It was only visible when I was on the ground looking under the engine. It freaked me out when I didn’t know what it was, as I always think any abnormality means the engine is about to blow up. The tech told me (after doing the work) that such puffing is cosmetic only and does not either harm the engine or indicate an engine problem. I don’t think I would have it done again unless it returns and becomes much worse.
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I have always left my Coach running,If it is running you know it will start!! Just one less problem when you are on a tight schedule from Venue to Venue,City to City every night.
Robert
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Robert,
Welcome back……how’s the project coming.
As I read the posts one thing keeps going through my mind. WHY? What is the benefit of running the engine? Letting it idle before shutdown I get. That’s a good practice. If Joel needs to run the OTR because his Cruise Airs are ineffective then the solution is to fix the Cruise Airs. If Robert had to run the engine because he was worried about it starting he needed to get the coach in for service.
Yes starting an engine does subject it to wear, but that is if you are talking about a cold engine that has not run for a while and the oil has flowed from the surfaces. I doubt if any wear occurs from re-starting an engine after it has been sitting for an hour or two.
If the engine is running to provide power for devices like ACs, run the generator. First, our generators will rust out before they will wear out. Robert will confirm that entertainer coaches run their generators almost 100% of the time and their life is measured in tens of thousands of hours. Run them, they need the exercise.
But what is the reason for not shutting down? I don’t get it. And just because the truckers leave their running I suggest they are not the best examples to follow.
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Now my experience will be a little different because I am a two stroke guy. I love my V92s! Old Detroit guys have told me not to just start the engine for exercise like you would in a car. The engine doesn’t need it. Don’t start it just to idle it. If you are going to start it, drive it. Keep the batteries charged with an external source. I bought an Eagle a few years ago that had been sitting in a barn for over 5 years. The guy was going to make me have it towed because he didn’t think it would run. I told him that I would pay him, sign a release, and he would no longer be responsible. We had the bus running and ready to go in about 15 minutes. Primed the fuel system and it started on the second turn and purred like a kitten. If you don’t feel comfortable with this and just want to run it every now and then, just make sure you have fast idle on for load.
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