Proactive maintenance question

[275hooah]

Hello,

I'm getting ready to buy my first Class A this winter, for an initial three month trip to Wyoming and back. At 62 y/o, I hope to get at least ten years of touring the beautiful country, West of Rapid City, SD and Dallas, before I have to go back to hotels.

One issue I'm having is, no matter how many combinations of key words I use, on Google, some of my research comes up short, so I am building a list of specific questions that I want to ask everyone here.

Having narrowed my focus to a Cummin's diesel engine (Probably 300-350 hp), here's the first question: What can/should I do to the engine, to be proactive and avoid any major/costly surprises on the road? Things like replacing parts with better parts (like the lift pump, filters), maybe using braided hoses instead of rubber, checking the dowel pin, more lube on this and less stuff on that and stuff like that.

There is a local Cummin's service point, and they will do a pre-purchase inspection, but their in the garage with manuals, while you guys are on the road.

Thanks ahead of time

[Skip426]

First Class A and a winter trip to Wyoming ; am I reading that right ? If so your one brave individual.
I'm hoping you mean buy in the winter travel in the spring.
Can't remember how many years of Cummins had the " Killer Dowel Pin " issue , or if there was a problem with the ISCs as well as the ISBs. I'm sure someone with a better memory will be along.
Electric lift pump was an issue in the Dodge Cummins 98>05 till they moved it back into the tank ; from the side of the engine. MH chassis could still be an issue because I'm sure they don't mount them in the tank.
JMHO. If you have a choice of ISB the 5.9/6.7 or the ISC the 8.1/8.3 go ISC.
Ask away , questions and answers are what the forums are all about.

[275hooah]

Thanks,

You're right, it does read like I was going to make a winter trip. Nope! Not THAT crazy. Drove a semi for a very short time, but in that time I managed to hit Cheyenne in some crazy snow conditions that shut the highway for two days, watched the trailer try to pass me on some ice and had a window blow out from the extream temperatures. No, this will be a late May departure.

My budget isn't as fat as some other buyers so I will more than likely end up with a 1998-2001 5.9 ISB model. From what I read, it'll be a good engine, but that 8.3 sure would be nice. Think I've seen the 5.9's in the 300-330 hp range and that will do for a 37 footer. I travel pretty darn light any more. Funny how the used prices seem to be a direct reflection of the hp isn't it.

Unless the motorhome I pick already has an upgraded lift pump, I think that would be a quality upgrade, so that's on my list. Because the pin MUST be on their inspection sheet, the Cummin's service department will probably check that, but I'll make sure.

Any thoughts on the engines lungs? Exhaust pipes, filters, mufflers, their size or manufacturer?

Thanks

[spike45]

Originally Posted by Skip426

First Class A and a winter trip to Wyoming ; am I reading that right ? If so your one brave individual.
I'm hoping you mean buy in the winter travel in the spring.
Can't remember how many years of Cummins had the " Killer Dowel Pin " issue , or if there was a problem with the ISCs as well as the ISBs. I'm sure someone with a better memory will be along.
Electric lift pump was an issue in the Dodge Cummins 98>05 till they moved it back into the tank ; from the side of the engine. MH chassis could still be an issue because I'm sure they don't mount them in the tank.
JMHO. If you have a choice of ISB the 5.9/6.7 or the ISC the 8.1/8.3 go ISC.
Ask away , questions and answers are what the forums are all about.

I do not recall that the ISC ever had the dowel pin issue. That was confined to the B5.9L. As for preferring the ISC over the ISB, I totally disagree with your choice. The B series engines are far less trouble prone than the ISC and way less of an issue than the ISL. Both the ISC/ISL engines have replaceable cylinder liners and require careful attention to the coolant for chemical protection against cavitation pitting. The B and ISB series do not have this issue and are much less picky about suitable coolants and coolant maintenance other than to keep the system full. Trust me on this one, this has been 70% of my work life as a field engineer for Cummins (Fleetguard) for 23 years before retiring January 2012. While the B engines do not have the "neck snapping acceleration" of the ISL, they spend far less time in the shop. The ISL was the first engine in the Cummins lineup that was designed with major cost reduction as paramount in the engineering....how to make it cheaper, not better. The new ISB 6.7 is a continuation of the good standing that earlier ISB and earlier B5.9 engines had.

What's with the Cat 3126? In another life, I was a field engineer with Caterpillar on the forerunner to the 3126, the 3116....what a piece of work that was. A sorry engine, indeed, as it had a mechanical fuel system that had a nightmare hydraulic governor so complex that we were not allowed to fix them in field trials, just replace them and let the non-Caterpillar supplier fix it. Caterpillar was a fine name in automotive diesels but went to pieces with the beginning 3176 and smaller 3116. More than a few sorry owners of Cat C7 and later. Introduction of ACERT really nailed the lid on them. Too bad, I bled yellow for several years after coming to Cummins (Fleetguard). Eventually, I saw what really great engines Cummins produced, if you do not count the Big Cam IV!

[275hooah]

Hello,

Congratulations on your retirement! You made it! I hope you enjoy the heck out of it. I know I am.

I had considered a motorhome with a Caterpillar, but the Cummings are more prevalent on the used RV market, have a healthy number of repair locations and I understand Cat is out of the over-the-road market now. Cummin's is the engine I've decided to pursue.

In just about everything i see on the Internet, the 5.9 ISB has a very dependable history, and dependability is what i need. The Bosch injectors and pump get good reviews. The issue of hp was a concern in the beginning of my search but I'm coming to understand that, on my budget, factory 330 hp is about all I'll be able to afford. There are methods to increase hp on these things, but hardcore, stock dependability is what I'm in need of now and the 330 hp 5.9 ISB is sounding good.

I'm not a commercial, 16 wheeler driver, so the six hours i will be driving, every few days or so, will be slower anyway. For every up hill there's a down hill so that's only three hours of getting passed occasionally and heck, that happens all the time, on my daily walks, so no biggie. Kind of the turtle and the hare situation.

With all of your time on the engine, what do you think I should ask the Cummin's inspection mechanic to look for or pay special attention to? Also, what, if anything, would you suggest I have done to the engine, or upgrade, prior to hitting the road?

Thanks

[vraines]

First, have Cummins run a diagnostics on that engine. Should see active and non-active fault codes and other health issues. I have had a couple of ISB's and the lift pump is certainly a concern. Also the exhaust headers have been a problem on some of the 8.3's. Early ones were one piece and sometimes broke. Replacements are two-piece. Pay close attention to the intake system. If you see problems here, you should suspect dusting and an oil analysis might be in order to look for silica.

[Hooligan]

5.9 or ISB Engine- The dowel pin is used to align the gear case with the block. There is no easy check by a mechanic. The timing gear cover has to be removed to see the pin. A major undertaking and the same work that would be done to repair/restrain the pin. (Cummins has a loctite fix after getting to the pin, another fix involves a blocking tab to cover the hole- easy fixes once you get to that point)
Early versions of the gear case had a drilled hole and press fit for the dowel pin. Some pins were able to move and could back out, damaging the gears or gear case. Cummings re-designed the case (twice actually) and newest cases have a lip to retain the dowel pin. (it now has to be pressed in from the back of the case)
Rumors abound even from Cummins- it affects- "Only the 12 valve engine, all 5.9 up to 2004, or only before 2002, only pick-up truck engines, ISB has different case and the pin can't come out." And each is contradicted by someone.
Recent reports of dowel pin failures are very rare.. basically none here on IRV although this has been discussed any number of times..
But if the killer dowel pin (KDP) does dis-lodge the damage can be catastrophic..

[275hooah]

Hello,

vrains, It looks like I should have a talk with the local Cummin's service location, to ask exactly what a used motorhome inspection would include and if there are additional options like oil diagnostics. That would give me a base to build on.

Would you elaborate on the "dusting" condition for me. What is it and why would i be looking for silica?

Hooligan, This pin information, and the dusting issue, are the kind of information that will serve me well at the inspection. The word "catastrophic" pretty much tells me to have the pin inspected unless the service location, or the seller, can show me that it's been taken care of. When modifications like this are made, isn't there a method of noting it on the vehicle or on the companies records? Seems like a reasonable thing to do.

On that thought, shouldn't Cummin's know, specifically, by serial number, which block has, or could have issues, what the fix is and whether it's been fixed or not?

Thanks

[spike45]

Originally Posted by 275hooah

Hello,

Congratulations on your retirement! You made it! I hope you enjoy the heck out of it. I know I am.

I had considered a motorhome with a Caterpillar, but the Cummings are more prevalent on the used RV market, have a healthy number of repair locations and I understand Cat is out of the over-the-road market now. Cummin's is the engine I've decided to pursue.

In just about everything i see on the Internet, the 5.9 ISB has a very dependable history, and dependability is what i need. The Bosch injectors and pump get good reviews. The issue of hp was a concern in the beginning of my search but I'm coming to understand that, on my budget, factory 330 hp is about all I'll be able to afford. There are methods to increase hp on these things, but hardcore, stock dependability is what I'm in need of now and the 330 hp 5.9 ISB is sounding good.

I'm not a commercial, 16 wheeler driver, so the six hours i will be driving, every few days or so, will be slower anyway. For every up hill there's a down hill so that's only three hours of getting passed occasionally and heck, that happens all the time, on my daily walks, so no biggie. Kind of the turtle and the hare situation.

With all of your time on the engine, what do you think I should ask the Cummin's inspection mechanic to look for or pay special attention to? Also, what, if anything, would you suggest I have done to the engine, or upgrade, prior to hitting the road?

Thanks

Have a Cummins distributor check the engine. For the ISB, the fault codes (if any) are stored in memory. If the MH you buy does not have the correct Operation and Maintenance Guide for your engine model and year, buy one from Cummins. Do not rely on this forum for maintenance advice like which filter to use. The O&M Guide is the source for this. As with any forum you get a lot of opinion from users. Some of it is good and some not so good. You are wise to leave the engine as Cummins manufactured it. More power can be had with modifications but in the long run at the cost of engine reliability. If you are considering repairs of your own, remember this....it is not your first car when you were in high school. Repairs on Cummins and other diesels requires specific knowledge, specialized tools and $$. Plus, when you 'fix' it and it breaks again, you can do it again at double the cost. Cummins distributor labor rates run, on average, $160 per hour. But if it breaks because of something they did, they pay the second time. When you buy a diesel pusher with the idea that you are going to do the repairs to save money, then get a Class C with a gas engine. You can afford it better.

Last sage advice from a guy who does not own a motorhome, there is a lot of good advice from those who do own them and have encountered the common complaints such as running hot due to rear radiator plugging with dust mixed with crankcase vapors. ISB before 2010 had open crankcase vapor disposal. The best fix is a long hose that attaches to a collection bottle with some steel wool or metal scrubber pad and vent holes. Periodically dump the bottle and clean it out. Periodic radiator cleaning is a must. The best cleaning solutions for this are called glycol ethers. Simple Green may contain this but I would shop some industrial cleaners such as Dober Simply Better. Dober Chemical. Sprayed on full strength and allowed to soak, these cleaners can be simply rinsed with water, not nasty petroleum solvents, etc.

One last thing then I shall step off the soap box; engine oil. This is one of the sacred cows of myth. Amsoil i such overpriced baloney. Use a name brand 15w40 engine oil, class CI-4 if you can get it, CJ-4 as that is the most prevalent now. Personal opinion plus some experience tells me that I prefer Chevron Delo 400, nothing less in their product line. Mobil Delvac 1300, Valvoline Premium Blue 2000, Shell Rotella, Conoco HD Fleet Supreme. By all means avoid Royal Purple. In my opinion and experience this oil is not nearly what it is said to be. Thus Amsoil which is an overpriced nitch product does not have any knowledge that the big lubricant companies do not already possess long before Amsoil. Most of these oils can be found at truck stops. Some at Walmart.

[275hooah]

Hello,

Hooligan, I found a pretty good visual of the pin on this site
( 24 valve cummins repair manual - free eBooks download )
It shows where the pin is, what it looks like, what the hole looks like and one method of fixing it. This illustration does not show the obvious disassembly required just to get to the front of the engine, if it's still in the motorhome. I can see the problem and expense this repair would cost. Not pretty!

spike45, There will be NO repairs attempted by me if I can help it. Paying a little more for the skills, abilities and warranties that shop mechanics offer is one of those mind-sets that has taken years and years to develop.

I will be looking at motorhomes with engines in the 1998-2002 time frame, so they should have the "open crankcase system" but in my searching, I see an "open crankcase ventilation system"
Clearing the Fog with Crankcase Ventilation
but no "open crankcase vapor disposal system". Are the the same thing?

Thanks

[Hooligan]

Originally Posted by 275hooah

This pin information, ...] [... When modifications like this are made, isn't there a method of noting it on the vehicle or on the companies records? . . . shouldn't Cummin's know, specifically, by serial number, which block has, or could have issues, what the fix is and whether it's been fixed or not?

Probably not unless the individual owner noted it in his records. Cummins is never specific, probably concern over redress.
It is an expensive precaution, and consider, the failure rate in the 24 valve ISB seems to be quite low, if it hasn't failed in 10+ years, it might not fail. It is almost in the category of lightning strikes, sink holes, bridge collapse and Poopsicles.--possible but not likely (My response) -- OTOH it can fail if not addressed. There is a less expensive alternative, but again since the failure rate is low and this article is dated, finding the jig or a mechanic experienced in this repair may take some leg work. Ram Diesel KDP retainer but it's interesting reading.

[MRUSA14]

Do not obsess over it. My ISC had 10 years and 67K miles when I traded it (I bought it new), and with the exception of replacing the lift pump there was never a single repair on it. I expect it will continue to perform for the new owners for many many miles. Just read the manual and make sure the prescribed periodic maintenance has been done and continues to be done on it.

[Hooligan]

Both Gary and Marc have good points. These engines, particularly the ISB are very reliable. Routine maintenance will keep them that way.
Online, Freightliner has a program "Access Freightliner" which provides a chassis parts list and wiring diagrams based on your vin number, Cummins provides parts,manuals and service info on their engines based on Ser. Number through their Quickserve program.
I'd also recommend a good air brake manual, there are some important differences.

When the unexpected does happen, there are good emergency road service programs available that cater to motorhomes or RV's.

[275hooah]

Hello,

OK, to sum up what I'v learned from this thread, and considering where my purchase is probably going to be in age, I could do worse than picking a motorhome with a 5.9L ISB 24V Cummin's engine on a Freightliner chassis. I should take advantage of both the Access Freightliner and Quickserve programs and insure I have all of the manuals that are available for my specific motorhome engine including the air brake manual.

The pre-purchase inspection should include a diagnostic of the engine and if possible, an oil diagnostic. Unless the lift pump has already been upgraded, I should just go ahead and have that done once I buy the vehicle. The pin issue, if not already noted as being repaired, will have to be a crossed fingers situation, but the odds are against anything going wrong.

Once the vehicle is mine, the local shop and i will perform any and all preventive maintenance by the manual, with attention to the tires, brakes, engine oil and the radiator and it's cleaning. I'll get the best insurance and emergency road service plan I can afford and go from there.

Thank You all for your input.