We have a new-to-us 2001 FT U320 with the 450 hp ISM. The unit has 135,000 miles and required service is to include a valve adjustment at 120,000 miles. Cummins confirmed this and we have found a shop in Tyler, Tx that is authorized to do this adjustment. I also spoke to a Cummins representative to ask any other major difference with the 2005 400hp ISL engine we owned before this. I understood Cummins to say that we could use a Lucas brand additive to help with the injectors whereas on the ISL we were to use nothing. I think this had to do with having less pollution controls on this ISM. He was very complimentary of the ISM and that it should last a very very long time in motorhome service. The simple question first....do forum members use a fuel additive to the ISM diesel and if so what, or do you only use a biocide? Secondly, are there things that I should have the shop look at or do when we get the valves adjusted? (oil, filters have been changed) I do not want to miss a cummins expert looking at and, or doing anything else that should be done. Thanks. Mike
I use the Amsoil additive now and again and there is a report out on most of the additives done by a lab' as to how good or bad they are and names makes in order of merit. I seem to remember Lucas as being worse than using nothing. In other words it actually has a negative effect on wear.
Google -diesel additives--it should be there somewhere, I think the Diesel shop had the report done
John
Diesel Fuel additive research results (http://www.busconversions.com/bbs/index.php?topic=6609.0;wap2)
here is the link
The Diesel Place, perhaps? Lubricity Additive Study Results - Diesel Place : Chevrolet and GMC Diesel Truck (http://www.dieselplace.com/forum/showthread.php?t=177728)
oh my, thanks.....surely do not want to use something worse than nothing! I got a private email with some help on a product that sounds interesting. A friend with a Ford pickup diesel uses something else, I need to get this part straight. I am anxious for the cummins approved mechanic to look at things; I doubt MOT looks at an engine to the same degree as a cummins mechanic?
Mike, This is an interesting subject. I have the Ford Diesel 6.7 L 2011, Ford recommends their additive in the fuel tank, I have used it sometimes, it does improve mileage and the exhaust cleaning event happens less often when using it.
Do not recall the name of it, but it is in a small red bottle, sells for about $5.00 and they recommend one bottle every tankful that is about every 38 gal. Little too steep for this cheap and tacky fool, that adds about 12.5 cents a gal. That would be about $25.00 to fill the coach worth of additive. Surely there is another better priced additive, maybe even from Cummins, will check.
Merry Christmas
here is the link to that study
Diesel Fuel additive research results (http://www.busconversions.com/bbs/index.php?topic=6609.0;wap2)
There is no comparison between an ISM and an ISL. The ISM is classed by Cummins as a Heavy Duty diesel truck engine. Many 18 wheel tractors pulling freight use the ISM. It is a very robust design producing similar HP to the ISL but without the issues that ISLs experience. Consider this, the ISM and ISL have the same HP ratings but the ISM with 11 liters produces that power will less stress to the engine. The ISL is lighter in weight but lacks the robustness of the ISM. The ISM has a long history dating back to the L10, later M11. They are heavier but their original market was powering line haul tractors in large fleets. The ISM and its big brother, the ISX 15 are Heavy Duty thoroughbreds. Sure, I am biased but having worked for 22 years for a division of Cummins, I got to know this fine engine and respect it. It is one of the least problematic of engines. Caterpillar has no equal to this engine's reliability, and I was a CAT guy for 20 years before Cummins!
Spike45
Gary Spires
RETIRED Cummins (Fleetguard) Field Service Engineer
So Spike, what's your opinion on fuel additives?
Hi Spike,
What is the difference between the M-11 in my 1997 U 320 and the M-11 style engines in the 2000/2001 years?
Dave M on this forum mentions different upgrades to the later engines. Are you familiar with what they may be?
Thanks,
Raymond
Additives - what ever you do - do not use Lucas Oil Stabilizer in your crankcase. It "washes" the piston walls. I know a guy who rebuilds diesels and he can tell every engine he tears down that has seen Lucas engine oil additives.
Spike45, thanks very much for your review and analysis of the ISM, ISL and the history of use and durability. After I get the valves adjusted, I will try to report back....that will give me a chance to visit with Cummins folks about additives, face-to-face. For sure I will not use the Lucas. The friend of mine that followed along with me and bought a 1999 with the ISM said it was remarkable the difference in it and the 1997 FT with the 300 hp cummins he traded. He thought the 1997 wonderful, so to be impressed by the ISM would be good to know. Mike