[Archived]

Personally I don’t like to idle my engine for long periods, but if I have to I set it to high idle.

Extended idle time wastes fuel and low idle speed especially in the north in the winter will barely keep the engine warm. I would not worry however about coaches idling at service facility because there may be a reason for extended idling. With our generator or when shore power is available we have no reason for extended idle, but once when we were spending the night in a parking lot in minus 26 degrees F we idled all night just to be assured the coach would run in the morning.

[Archived]

If I have to, or want to let it idle, I put it on high idle. It keeps the oil pressure at a higher level, temperature more stable, and also lets the alternator(s) produce more power if it is needed by accessories that may be running.

But as Jon said, if you can be plugged in, there isn’t much reason to let it idle. Running the generator is also more fuel efficient than running the main engine.

[Dick]

No harm on high idle Roy, runs smooth and the belts aren’t flopping around.

[Archived]

Well, we have the Volvo engine and I try and idle as little as possible just for the sake of not disturbing the other campers.

First, I have to start the engine so that I can reach ‘ride height’ for pulling in the slides. I start the engine and let it run for a minute or so then hit it the rabbit switch for high idle. I wait for the air system to ‘sneeze’ then I go to the rear of the coach and hit both rear slides buttons to pull both slides in (then count to 7 so the seals fill up).

Then, I go to the front to pull in the front slides. The front slides have to be done one at a time (not like the rear two slides). Once the first front slide is in, I again count to 7 so the seal is full then move to the other front slide.

That’s at least several minutes of idling. While all of this is going on I’m filling the fresh water and emptying the holding tank, then we are ready to roll.

Safe travels,

Mark

[Archived]

In campgrounds I make sure everything outside is done and I’m unhooked before starting. Then build air and ease out as quick as possible. I usually find a spot near the entrance/exit to warm up a little on high idle before hitting the road. I’ve seen plenty of the 1/2 hour idle nit wits that seem to want the entire Campground to know they have a diesel. Just pisses everyone off.

[Archived]

ok, Jon, I have to ask were you warm inside the coach at negative 26 degrees?

[Jim/Chris]

Tom and Mr. Mark … how much water temp are you typically showing before you pull out of the campground, RV resort, or home?

[Per]

I also minimize idling. In a campground, I first check to see if the belts are tight, if not, give a boost from the Marathon aux system. When i start the coach, leave it at high idle until Prevost aux pressure is up, and if required, the suspension is up. When I get out of the campground, I limit speed to 55 MPH until I have 150-180 degrees on the coolant. I also try to avoid full throttle if possible.

[Harry]

Dick,

I’m usually showing about 170 when I start to move the coach. If below 45 degrees at night, I’ll turn on the block heater to exercise it.

Mark

[Jimmy]

The night we spent in the coach at 26 below (the coldest we ever experienced) we used the high idle and OTR for heat. We had to get up twice during the night to turn down the heat because it got too hot in the coach.

It was the only time we ever allowed the bus to run all night and the only time we ever used OTR for heat, but it did a great job. We spent many nights with it hovering near zero, but that coach had five electric toe space heaters, plus three propane “furnaces” so we had all kinds of ways to stay comfortable.

[Harry]

It seems the issue in this discussion is whether or not idling hurts the engine or any other parts of the drive train?

If I am not mis-taken, Detroit Diesel put out a bulletin some time ago discussing the fact that diesel engines at idle can be very ineffcient……..the result being that the unburned fuel that is not exhausted can experience a form of “blow by” and be injested into the oil supply of the engine. If, thereafter, the engine sits for any prolonged period of time, a form of acid is developed that attacks the main bearings.

This may be a wise tale but I believe there is evidence to this effect…. what does the group think?

I cut my engine off if possible after five minutes… that is because I am paranoid.

As usual, I understand the question… I am not certain that I have the answer.

.Pres

[Archived]

The Pres wrote: “If I am not mis-taken, Detroit Diesel put out a bulletin some time ago discussing the fact that diesel engines at idle can be very ineffcient……..the result being that the unburned fuel that is not exhausted can experience a form of “blow by” and be injested into the oil supply of the engine. If, thereafter, the engine sits for any prolonged period of time, a form of acid is developed that attacks the main bearings. “

Presuming the Pre is not mis-taken about DD’s bulletin … why doesn’t DD do an update to the fuel injection control program to reduce the amount of fuel being squirted into the cylinders so their isn’t “blow by”? Or does that create other problems?

[Archived]

If we have to idle for an extended period we have the option of using high idle which maintains a higher engine temperature and as a side benefit increases the alternator output for those equipped with OTR so the batteries are maintained while running the fans for the evaporator and condenser.

I’m not advocating we allow our coaches to idle for extended periods, but if we have to we should use high idle.

Also, when in traffic jams I don’t know what Prevost or Allison suggest, I put the coach in neutral when pracrtical. That tends to let the transmission cool a little.