I heard that it may not be good to idle the engine to lubricate seals and parts without driving the motorhome. So I asked Cummins, is it necessary and, or damaging to idle once per month without driving, and if so, how could I do this as it would not reach higher temperatures. This is their response. Please note, Cummins has my engine "ID" so we are talking only about a 2001 vintage ISM. They said,
"Normal driving would lubricate everything on your engine. If you are not driving the vehicle all the time, high idling it would not be a problem. The main reason Cummins does not recommend idling is because it is not necessary anymore on the newer engines and it can harm some Aftertreatment components, but your engine is a 2001 and does not have Aftertreatment components. Please make sure to get it up to operating temperatures before high idling. You will not harm anything from high idling.
That engine, the ISM, is also popular in grain trucks for farmers who only use them during harvest and they do the same thing as far as high idling."
......so I wrote back, what is operating temperature? I doubt I can get above 120 or so in low idle just in the RV shed. I also wrote them that I was concerned about shutting down the engine without it getting pretty hot (might form condensates?). they responded...
"If the customer wants to perform a high idle, make sure the engine is not going into high idle right at startup. Coolant temperature range should be between 184 to 195 degrees Fahrenheit, but if the chassis does not have a coolant temp gauge, true operating temperature will be hard to tell. If the customer lets the engine idle for 10 to 20 minutes, it will be fine to put the engine on high idle for an extended period of time. Please bear in mind that time is a variable because high idling an engine is not a Cummins required maintenance procedure. This is only a guideline if the customer wants to perform a high idle. He is correct about not getting the engine hot enough too before shutdown, all these variable make it impossible to specify."
What I took from this, for my engine I do not need to exercise it but if I do, I can go to high idle after about 15 minutes at low idle even without reaching 180 degrees and some newer engines should not be left to idle. It is best to not idle to just test the engine, charge batteries or whatever without getting the system hot (i.e. drive it or use high idle to get it hot). Any ideas if I have this right or alternatives....?
Which is what Brett Wolfe has wisely indicated over the years. :)
As someone here posted recently I noticed my 600 rpm idle set by my mechanic allows two fast idles. One at 800 rpm with the set button and a 1200 rpm one with the resume button.
Bob
Thanks Mike - Did not know that.
They failed to give you the primary REASON for not starting the engine unless you can get it up to operating temperature (and actually which "fluid" you need up to operating temperature.
Even if the COOLANT gets up to operating temperature (possible at high idle), it is the OIL/CRANKCASE that you need up to operating temperature. If you don't, all you will do is add moisture to the crankcase.
So, unless you can drive 25+ highway miles, starting the engine is NOT recommended. Both Cummins and Caterpillar review this at their maintenance seminars such as the ones they present at FMCA Conventions.
And, while most "factory" responses are correct, they are not chipped in stone. I attended a Freightliner Rally (I was presenting another seminar) where a Cummins rep was doing a Cummins maintenance seminar. By the middle of the presentation, it was obvious that she did not even know that the cooling package (radiator and CAC) were in the BACK not front of the coach. These are PEOPLE, and not all are schooled in technical matters. Probably very few industries, particularly in the last decade that haven't gone the same direction as a cost saving measure. The move is either to low-wage employees here or outsource overseas.
Most call centers today are not manned by technically competent people. They are manned by much lower wage scale employees who for the most part have one of two answers: "please consult your owners manual" or "please consult a dealer". Been there, done that for 25+ years in the automotive business. Stepping off my soap box now.
Brett
"They are manned by much lower wage scale employees who for the most part have one of two answers: "please consult your owners manual" or "please consult a dealer"." Those answers are also usually in some sort of foreign accent, too, and most of the men are named Bob. In order to talk to "Bob" though one must wait for 10 minutes or more listening to something that is supposed to be music, interspersed with advertisements for the product you are calling about.
I have not ran into the foreign accent at Cummins yet. And both my PenFed and UnionPlus card's customer service call centers are both U.S.A. located.
Just for full disclosure on this matter, Brett and several owners here at an RV park had this discussion and I knew his answers and feelings on the matter. I thought by posting this it might renew interest in this topic for, as we here had talked, there was not common opinion or knowledge on this. In addition an experienced mechanic had alternative views And my question was broader in one respect, having to do with allowed idle time (I had been admonished to not idle for a lengthy period - not by Brett, but others with experience plus owners manuals) and I did not know about the idle differences in the different vintage Cummins engines, so that was new to me and perhaps of interest to others.
As for low wage, foreign folks, etc., that has not been my experience with Cummins Customer Care. I guess I have just been lucky to avoid those respondents but based on my calls to them I think it right for me to say my experiences have been good.
Hope this dialogue (idle) has helped a few people be aware of and, or renewed interest in the topic.
While our coach does not set for more than 2 or 3 weeks at a time, and at times runs only about 15 mi to a local camp ground, I do not hesitate to start it when the need arises (to back it out to wash it, or build air for some reason). 8 years of annual oil samples indicate no issues in the oil. JMHO one would have to do a bunch of very short idling sessions to create a problem between annual oil changes.
some of the best mechanics are "foreign" and with all the different dialects in the country "what is foreign"??
John H
Just as has been said it's condensation in the engine caused by cold idle that's the problem. Over the years of running fleets with a lot of diesels we never found it to be a problem. Vehicles would be started and moved without ever getting up to running temperature BUT this was here and there. Doing it a lot time after time and you will get condensation and sludge build up. Long periods of slow idling is a problem with the engine cooling down and unburnt fuel washing the cylinder walls and reducing their lubrication. Engines that were treated that way showed more wear than ones that had a normal duty cycle.
Despite all the abuse handed out by the operators and the demands of municipal type operations we had very little trouble with our engines. The duty cycles were far harder than that which an RV would subject them to. Just think of the life of a garbage truck, bus or snow plow truck. Maintenance is the key here. Look after it and follow the manufactures recommendations and you should be fine.
Just my experience.
Keith
Was it here on this forum or someplace else that I read about the oil being as drained down as it's going to be in 7-8 hours? The point being that unless you start it within that period there is going to be no benefit to starting to keep the oil and stuff circulated and parts lubed. I only start when I'm going somewhere or need to move the coach for a wash, etc. other than that it just sits sometimes for three or four months and seems to be happy. I have a friend who says I should move it a foot or every month so the bearings won't cause a dent in the bearing races. It's a good thing he's a friend since that doesn't make any sense. What if you moved it back to the exact same spot and then began denting the race again? Lots of things said that don't really make sense.
Larry,
Taken from Cummings recommended practise:
Whenever an engine has been inoperative for more than 30 days, Cummings recommends disconnecting the wire to the fuel shut-off valve and cranking the engine until oil pressure registers on the gauge before starting the engine. This practice will prevent "dry starts" and allow oil to bearings and shafts prior to starting the engine. A toggle switch can be wired into the starting system for this.
I don't think you will "Dent the bearing races" Bearings are heat treated and the metal would not cold flow.
Keith
Larry,
Your friend is talking about "false brinelling", whereby a bearing race can end up with indentations from the balls -- over time while sitting stationary. HOWEVER -- this only happens if there is a vibration present from an outside source. It was common at heavy manufacturing sites when you had heavy rotating equipment sitting still on maybe a pallet, in the presence of other running equipment with the normal vibrational forces that travel through the floor and building structure.
It is why all of this stationary equipment has a predictive maintenance program requirement to be rotated by hand once a week or so. I would see newly installed equipment when I did vibration and modal analysis for a living, that upon initial start-up would have prohibitively high vibration levels due to the condition.
So unless your Coach is sitting on a surface where there is a surrounding environment of heavy industrial vibration (like a factory floor) -- I wouldn't worry about it.
False Brinelling | NSK (http://www.nskamericas.com/cps/rde/xchg/na_en/hs.xsl/false-brinelling.html)
I just want to say that I continue to be amazed by the level of knowledge and general intelligence on this board. The downside is that I am also constantly reminded that one probably shouldn't own one of these things without similar levels of both or a lot of disposable money to make up for it.
If your all that concerned about lubricating the engine without building condinsation, the very best method would be to install Jocky pump, pump oil through the engine to pre lube it / float the bearings.
We did this on some generator systems years ago whil using the "No Brake System". You old Engineers would recall those days.
Biggest issue I've noted centers around not allowing a diesel time to warm up before putting it to work. A poor analogy would be getting up from a good nights sleep and going for a run without stretching.
Shutting a hot unit down without allowing the oil temp to drop to whatever minimum is considered normal is another issue that creates problems.
As for running a diesel to keep things lubed, IMO (after dealing with these things since I have worked on them since my early teens) it's a waste of time for anything other than determining the overall condition of the engine. If it cranks over and rattles like a box of rocks, it is a box of rocks.
Case in point was a D13000 (CAT) I pulled out of a (much earlier) wrecked shrimp boat that was (much) later re-fitted into another shrimper. This wreck set on the beach for months and was moved 40 miles (drug through the sand dunes) where it sat another 10 plus years until I got what I wanted for it. Once it was in place and the pan washed out and cleaned up (less than more), the donkey kicked it over, the oil pressure came up & the fuel turned on and it's still running 40 plus years later with no issues other than fuel not being $0.27 a gallon anymore. The original owner I sold it to has passed it down for 3 generations and it's still plugging along turning a whopping 700 RPM at max output and it idles at 600 RPM. This monster lives in NSB FL in a 60 year old shrimper, still making money and it runs like a CAT full of cream (after sitting for a dozen years).
It's a waste of time cranking up an engine to keep it lubed unless you get your kicks listening to a diesel.. IMO. pc
Yup, th D13000 Kitty at 115 hp and about 12,000 lbs sure is a throw back to th 30's think was replaced with the D353. Working for Cat taught me to never buy a Cat. :o
I know what the friend is talking about with the bearings and thought it was a good thing he was a friend and didn't laugh. Concerning the 30/disconnect and cranking thing. If I were going to sit for 3-4-or 6 months, why would I be sure I'd crank it up every 30 days it I could save the trouble and fuel and time and simply to the dry-start thing? I think that makes more sense. Any I agree, the knowledge on this site is worth the price of the coach.
Concern with starting any engine is where a lubricant enhancer enters the equation. In light of the (rather) negative responses (I am sure) most everyone has noted, tends to lead me to NOT bring the topic to this forum in spite of the fact that there is a product that greatly reduces dry start issues.
The product has been around for decades and is used in areas limited to ones imagination.
DuPont issued disclaimers stating the concept was "pie in the sky" yet today produces a product not knowing the formulation or its blending process.
So it goes,
pc
Were we seeing or even hearing of bottom end failures on these engines, it might be worth considering a pre-oiler.
But, buying a product to solve a non-problem-- well.........
8v92 birds had a Pre oiler. Stored 30psi if memory serves me. And had a ten quart oil tank in the engine bay with a quarter turn handle and a level sight tube for the oil tank. Needed on an 8v92.
Bob
Have never seen a "Pre oiler" on a DDC, however have seen an accumulator that held pressurized lube oil that got dumped into the turbo bearings during start cycle. Yes, some of the uncared for DDC engines would enjoy having a spare oil tank to refill simply by turning a valve. A good DDC engine would run 5,000 miles and not need to add oil, the ones that had no to poor servicing would need oil added more frequently.
They do require a little more TLC than the Cummins & Cats in general.
Yes accumulator was the correct term. You are correct as most oil I added was a gallon at 5k miles from a change.
Bob
Should have mentioned the accumulators I have seen were on large engines, not the DDC small engines, big engines such as the Cat 3500 & 3600 series, and the Waukesha engines that make big hp. All are auto start and go to full power within 8-10 seconds. Turbo bearings need lots of oil right now.
Most RV types treat their engines as if it was a Hemophiliac.
Wow my memory is coming back. Used to install a fifteen minute mechanical timer in the dash on coaches sometimes. After a hard pull and then parking the engine would idle for up to 15 minutes then shut off while the owners were having dinner.
Cooled the engine and turbo down versus bake the oil in the turbo at the bearing surface.
Bob
I've got a five minute shut-down timer. Just push the button and turn the key off. Drives people nuts when they stop to look at the coach and it suddenly quits! Lots of fun.
Larry,
That five minute cool down may be way too long. It really depends on driving conditions just before shut-down.
If you have just pulled a long grade and pull into a scenic pull off at the top, that would be just perfect.
But, if you have pulled into a CG and have idled while checking in, you can shut it down safely the instant you pull into your camp site.
And, if you have driven city streets getting to the CG, you can safely shut it down 3 minutes or so while checking in.
BTW, this is the advice from both Caterpillar and Cummins.
My slide rooms work better when I have the engine on. They pull from the chassis batteries so I idle till they are out and I am level so I always have about 5 mins of idle time on the coach when I stop.
I agree with the other Brett. If I HAD to idle for 5 minutes, I would use fast idle.
Some thought that the extended idle would reduce the engine compartment temps better for sleeping. Takes hours to cool a ton of hot steel.
Many customers asked for engine compartment fans for the same reason.
Bob
We didn't notice any extra heat in the bedroom, but then I think the latest we landed was about 6:30 p.m.
Two to three hours sometimes of heat. But we are dry campers and do drive late at night then stop. Especially a m11 setup.
Bob
oh in the winter especially in my old coaches the bed was warm as I pulled in to the rest stop at 9 pm for the night and fell into bed. I loved it. Now the closet is over the engine so no heat issues at all. Though I miss i in the winter. It would cool down in about 20 mins but it was still a nice feeling. I love winter camping more than summer.