Idling ISL with DPF

[LewF]

Anybody have any suggestions on this question? We have a Diesel Particulate Filter (DPF) equipped 425 ISL engine, built after 2006, and I would like to run it every two weeks when I can't get it out on the road. If I idle it under no load, I know not a great thing for diesels, I would like to run it long enough to get it up to near operating temps. The DPF doesn't like to operate at idle temps - in fact it won't burn particulate at these temps and may have to be actively regenerated. Soooo, anybody have suggestions as to how to run diesels with DPFs when you can't get them out on the road?

Incidentally, I used to be the chief engineer on diesel powered ships and sail them all over the world. Our rule of thumb was to configure the plant to keep maximum load on the running engines and my experience was they performed very reliably under those conditions. It pains me to not be able to do that with our coach engine.

Lew

[94-Newmar]

Lew, search around the forums.. I remember a thread awhile back on an obscure switch that may be hidden in the wiring under the dash to force a high idle regen for you. Perhaps others more familiar will chime in on this.

[nodine]

Quote:

Originally Posted by LewF Anybody have any suggestions on this question? We have a Diesel Particulate Filter (DPF) equipped 425 ISL engine, built after 2006, and I would like to run it every two weeks when I can't get it out on the road. If I idle it under no load, I know not a great thing for diesels, I would like to run it long enough to get it up to near operating temps. The DPF doesn't like to operate at idle temps - in fact it won't burn particulate at these temps and may have to be actively regenerated. Soooo, anybody have suggestions as to how to run diesels with DPFs when you can't get them out on the road? Incidentally, I used to be the chief engineer on diesel powered ships and sail them all over the world. Our rule of thumb was to configure the plant to keep maximum load on the running engines and my experience was they performed very reliably under those conditions. It pains me to not be able to do that with our coach engine. Lew

Lew,

Not sure if this is your question, but you should be able to use the cruise control with the transmission in Neutral to get the engine to idle at high rpm.

Bob

[LewF]

Bob, sorry I wasn't very clear in my rambling attempt to ask a question. I know how to control idle speed with the cruise control so no problem there. My problem is I don't know how long I can idle the engine without plugging up the DPF.

As you probably know the DPF is an emission control device on 2007 and later diesels that works something like a catalytic converter. However it has to get hot enough to burn the exhaust particulate or it will plug up - the recommendation is at least 20 minutes at highway speed. At this speed the DPF will burn the soot from the exhaust. At cooler temps the soot accumulates and then fuel is injected into the DPF to burn out it out - active regeneration. I don't think an active regeneration cycle can be performed at idle - it gets very very hot. I guess the bottom line is I will have to get this thing out during the winter and drive it and not let it set.

How have things been going with you. No more encounters with trees I hope. How did Buddy Gregg do on the repairs?

Lew

[nodine]

Quote:

Originally Posted by LewF Bob, sorry I wasn't very clear in my rambling attempt to ask a question. I know how to control idle speed with the cruise control so no problem there. My problem is I don't know how long I can idle the engine without plugging up the DPF. As you probably know the DPF is an emission control device on 2007 and later diesels that works something like a catalytic converter. However it has to get hot enough to burn the exhaust particulate or it will plug up - the recommendation is at least 20 minutes at highway speed. At this speed the DPF will burn the soot from the exhaust. At cooler temps the soot accumulates and then fuel is injected into the DPF to burn out it out - active regeneration. I don't think an active regeneration cycle can be performed at idle - it gets very very hot. I guess the bottom line is I will have to get this thing out during the winter and drive it and not let it set. How have things been going with you. No more encounters with trees I hope. How did Buddy Gregg do on the repairs? Lew

Now I understand your problem Lew.

Buddy Gregg did a good job with the body and paint work but they took way to long to do the job. I think they were using us for fill work. At any rate, she is back home now and we took her to Winston-Salem for the FMCA rally in October. While Buddy Gregg had the coach it seemed like every time I needed something it was in the motorhome.

Bob

[OLYLEN]

Why start it so often with "not getting to operating temperatures"? Without a load and this means driving for and hour or so you will be creating an environment for acid buildup in the oil. Diesels set for many months with no ill effects on start and run. And I don't know about the trans not getting to operating temps and circulating fluid. Mine have set for 3-4 months with no bed effects and starts are normal. Now starting the gen every month with load for an hour or so is another story and this should keep this batteries up. JMO

LEN

[RustyJC]

Starting and idling an engine without bringing everything up to full operating temperature is far more detrimental than letting it sit without running. Not only do you generate moisture (water is a normal by-product of combustion) and weak acids, but every start/stop cycle thermally cycles the engine components. This, in conjunction with the DPF loading problems associated with extended idling, would lead me to rethink my strategies during long periods of inactivity. In other words, why run it at all? The downsides are far greater than any potential benefits.

Our company manufactures engines and compressors used primarily in the oil, natural gas, process and refining industries. In some applications, these engines may sit without running for 6 months or more, and we certainly don't recommend periodic startups just for the sake of it. If, on the other hand, you could disable the fuel injection circuit and roll the engine on the starter long enough to build oil pressure (thus wetting the lubricated components such as crankshaft main and connecting rod journals), that might be beneficial.

Rusty

[LewF]

Rusty and Len, I think your advice is sound. It does look like the down side of running without coming up and staying at full operating temps is not a good idea. I am convinced so will concentrate on running the generator under load periodically and let the drive engine set until I can get on the road. Thanks for the info. - your experience and information matches my diesel experience so I am putting this question to bed.

Would be nice to be able to roll the engine once in a while but I think that is too hard.

Lew

[nodine]

Quote:

Originally Posted by LewF Rusty and Len, I think your advice is sound. It does look like the down side of running without coming up and staying at full operating temps is not a good idea. I am convinced so will concentrate on running the generator under load periodically and let the drive engine set until I can get on the road. Thanks for the info. - your experience and information matches my diesel experience so I am putting this question to bed. Would be nice to be able to roll the engine once in a while but I think that is too hard. Lew

Just so everyone understands, the main reason for running the generator at a load once a month is to keep moisture from building up in the windings.

Bob

[RustyJC]

Right. Large industrial generators such as those driven by some of our diesel engines have winding heaters to accomplish this, but these are up to 6,300 kW generators.

Rusty