Idling Diesel Pushers

[Mr_D]

On mine I can push the cruise button and it raises the idle to 1000 rpm. Much better for the engine but I don't need to use it very often since I don't let mine idle for very long.

[johndfd]

I agree with most, start up, idle a minute or two, then drive off slowly. If you are close to an interstate on ramp, I might add some more time for the temps to come up some. Keep in mind at idle, it will take a long time to "warm up".

As far as air filter replacement, which was mentioned earlier, I have read that excessive air filter replacement is not the best. The air filter is the most effective when some dirt is actually in the filter. As new dirt particles enter, they are trapped by the existing particles. The filter element is doing the best job as long as there is not a pressure drop across the filter that is excessive. More small stuff gets through a new filter.

I drive almost all the new diesel engines. DD13, ISL, ISX, ISB, powerstroke, etc. Old ones such as Mack, ISM, Detroit series 60, Detroit 8v92, 6v92, 8v71, you get the idea. The new ones have LOTS of issues, almost all emission related. Some issues are going to happen no matter what, the sensors are not the greatest, etc. My personal opinion is to avoid excessive idle time, use fresh DEF, run the motor hard at highway speeds to allow higher EGTs. If it is regenning, I allow it to finish the cycle if possible. When you get to a hill don't baby it. Some folks get confused and think DEF is some sort of fuel additive, and add it to the fuel tank. One fire truck...that was $17,000 bill, so that is not a good idea.

If a modern motorhome came with a Detroit series 60, non DEF, I would buy it. I really like the DD13 of today, so that would be my second choice. ISXs are fine, but they drink DEF hardcore so that is a small disadvantage for me.

[F4Gary]

I remember reading an article by Smoky Yunick where he said the best and quickest way to warm up an engine is to drive it.

[Cat320]

Verbatim from my DD 13 manual: "The common belief that idling a diesel engine causes no damage is wrong. Idling produces sulfuric acid, which is absorbed by the lubricating oil and eats into bearings, rings, valve stems and engine surfaces. If you must idle the engine for cab heat or cooling, the high idle feature of the Cruise Control should be used."

[Dav L]

Originally Posted by wildcatter

What??????? Where exactly did you hear this?

I certainly have read this...and I seem to remember in one of the documents from the owner's manual suggest this as well.
The ISM on mine comes with an air filter monitor device that looks at pressure difference on both sides of the air cleaner. The instructions say leave well enough alone until the monitor suggests a cleaning is needed.

From K&N:
"A Filter Minder works as air filter service indicator that monitor air filter restriction and indicates when the air filter should be serviced. As the air filter gets dirty, the yellow position indicator moves in the clear window of the service indicator and locks at the highest point. It can be read even after the engine is turned off. The air filter should not be cleaned until the yellow position indicator reaches the red zone.

A Filter Minder works as air filter service indicator that monitor air filter restriction and indicates when the air filter should be serviced. The air filter should not be cleaned until the yellow position indicator reaches the red zone."

[nothermark]

Originally Posted by wildcatter

What??????? Where exactly did you hear this?

Better filtering with some caked build up is old news. Off hand I expect the information came out of computer monitoring that was forced on the industry when they had to design better systems for fuel economy and pollution requirements. I expect the air filter testing was a carryover from gasoline engines as they got hit first with the legal requirements. It seems a lot of what was considered obvious was proven not to be when real testing became part of the design cycle. A large part of that was the development of more or less portable computer systems and constantly improving monitoring sensors.

[cruzbill]

I wonder what Adept Ape (Cat engine mech) would say about idling:

https://www.youtube.com/watch?v=hvfMal5fReA

[YC1]

If it doesn't work.

Read the book.

If it still does not work, Follow it. Words of wisdom from one of my teachers.

From the Cummins rep that gives us a seminar every year. Once off the freeway and to the fuel station or RV park it has cooled plenty.

Idling is a bad thing and I can tell you that the computer records the idling time versus running time. After replacaing my DEF filter that cracked and they told me I had High idle time I was stunned. I do not idle much but if you add up times sitting in a rest stop or traffic it can add up.

As for the air filter, he says to let the filter minder go up almost to the change point and punch it down again. When it gets up again then change the filter.

[cruzbill]

Air Filters:

Getting the most of your truck's engine air filters

[ga traveler]

I retired from being a service manager in 2009. I have not been to a Louisville dealer show since. I loved the Louisville show. You met the actual designers of the motorhomes and chassis and engines. Talking to the actual guy who designed the engine and took it through testing was a real treat. I talked several times about cooling engines. ALL engines gas and diesel should be cooled down. Every engineer said 5 minutes was best. Going over that time was actually bad for the engine. The reason they gave for diesels in particular was the turbo. The turbo is driven by the exhaust. The exhaust temp at highway speeds, in the turbo is terrific. (It has been years, but I think they said well over 1,000 degrees) They run engine oil through the turbo bearings to keep them cool and of course to lube them. If you shut off the engine right after pulling into a stop, the turbo will cook the oil in the bearings and You will have turbo problems. COOL DOWN yes but never over 5 minutes.

[Crasher]

Originally Posted by ga traveler

I retired from being a service manager in 2009. I have not been to a Louisville dealer show since. I loved the Louisville show. You met the actual designers of the motorhomes and chassis and engines. Talking to the actual guy who designed the engine and took it through testing was a real treat. I talked several times about cooling engines. ALL engines gas and diesel should be cooled down. Every engineer said 5 minutes was best. Going over that time was actually bad for the engine. The reason they gave for diesels in particular was the turbo. The turbo is driven by the exhaust. The exhaust temp at highway speeds, in the turbo is terrific. (It has been years, but I think they said well over 1,000 degrees) They run engine oil through the turbo bearings to keep them cool and of course to lube them. If you shut off the engine right after pulling into a stop, the turbo will cook the oil in the bearings and You will have turbo problems. COOL DOWN yes but never over 5 minutes.

Very true, however the 5 minute cool down starts when you slow down for the exit and because of reduced power and slower speed it is cooled to a safe level by the time you pull into a fuel stop or campground. Years ago, I had a pyrometer on a John Deere 4020 tractor that had 100 hp. However I added a turbo to it and it put out close to 155 hp. On the cool mornings, I had to watch it and cut back on the throttle to keep the egt below 1400*. (1450* sustained for 3-4 minutes would melt a piston) Normal operating temp was 1200*. When done at the end of the day, driving back a mile or so to the shop, the egt would quickly drop down to about 400* when I shut it off. That engine went for 6500 hours before it needed to be overhauled, but it had produced 50% more power than the stock hp for 2500 hours. The turbo was fine.

[Monacoach]

Originally Posted by wildcatter

What??????? Where exactly did you hear this?

Cruzbill has a good linc for you in post # 37 that explains why its bad to over service your air filters. Your anual filter changing could be hurting your engine and its costing you more.

[Ray,IN]

Originally Posted by Outbound

On the other hand you do not want to start and stop engine within 10 minutes, when we stop at RV park to check in I leave motor at idle, not sure if it's good policy but for check in it seems OK.

Why? What possible harm may occur today? That was true for diesels 70 years ago, as the starters were not of todays quality.

[irishguy]

Our 2003 Monaco Windsor (Cummins) has a fast idle switch...Is it less harmful to idle at the fast idle setting? Is the switch supposed to be used for better warm up and cooling down?

I have never idled for very long for the reasons stated in this post.

Irishguy