Motorhomes, RVs, road warts

NO! I don't want one. I hate the stupid things.

My father in law has one. He is not mechanically inclined. It's broken. I am mechanically inclined.

1999 Monaco something. Cummins 5.9 ISB 275, I think that means 24 valve. It's in the back. I think that makes it a pusher, or a class A, not really sure.

Leaks on at least one exhaust port. I must fix. He has two quotes for thousands. Many and many thousands. Apparently everyone is convinced they must send this thing to a coach builder RV specialist to remove the fiberglass shell hood/bed thing, then to a Cummins specialist to install a new head because they are convinced that the studs are broken or will break and they cannot be drilled out. I am convinced that they are lazy.

Nothing looked terribly rusty - it isn't salt driven. I figure if I blast em with penetrating oil and heat for a while they ought to just come loose, if they don't, I slice up the manifold and remove the studs with vice grips and heat and wax. If there are any already broken, I can drill or left hand tap and be patient.

Now.

How in the world does one find parts for a motorhome? Is the manifold the same as it is for Dodge trucks? I kind of doubt it. The gaskets would be, right? Right? Any hopes of even finding out what chassis this thing is based on (some sites say Freightliner, but not which one. Some say Roadmaster, which is a Monaco special) are lost, and I am not sure even that would tell me what I need to know. The motorhome is 1,000 miles away from my physically and the owner is laid up with recent crotch surgery, so he's not up for climbing in there and looking around.

Anyone with experience with RV Cummins exhaust studs? Does this actually happen or are the places he's contacted just shooing him away because RVs and RVers are annoying? Are they just Bob Costas? Are they all broken and a new head is really what the mechanic ordered?

Yes. Class A pusher.

I live near the Cummins service center in Bristol, PA. They work on RV's all the time, so I see no reason why it would need to go to two shops. I had them work on my Dodge whenever the engine broke (I hated working on that berking POS). No, they weren't cheap, but they knew what they were doing.

Any good diesel shop should be able to handle it. You might pay a little more for taking out the bed, etc but it is meant to come apart fairly easy for servicing.

It's a Magnum chassis. The bed should lift up without any major removal. I own a 2000 Monaco but mine has a Cat so I can't help you with the cummins specific stuff. Otherwise, engine access is very easy. Most truck repair shops won't work on rvs because of the perceived engine access problems. My parents own a newer diesel pusher with a cummins that does require major carpentry work to get to the top of the motor so they have to bring it to the $$rv$$ shop for service.

I've also learned that there is a perception that motor home owners have a lot of money and are stupid. Many shops capitalize on this.

RVs are just like I/O boats. If people just realized that an inboard boat engine is just a plain small block chevy, the would quit paying $9 for a spark plug. The fancy marine aluminum intake can be bought from Mercruiser for $632, but it carries the same exact casting number and part number as GMPP's ZZ4 intake which can be found on Ebay for $96 with free shipping.

The ISB is (in fact) the same basic 5.9L that Dodge used in trucks for years. That ISB design goes back a few years earlier and it is still in production in medium duty trucks. In most situations, the manifold and flange are identical regardless of the application.

The exhaust manifolds are prone to cracking. Make sure that isn't the issue. In some HD applications the rear manifold bolt will pop its head allowing a leak as well. Either way, there are no exotic weird parts. Its a Cummins 5.9. Period.

If its a cracked manifold, don't try to weld it. Some guys have welded them with mixed results. The aftermarket has solved the issue with a 3-piece exhaust manifold, but its pricey. If its cracked, just replace it with a junkyard piece.

curtis73 wrote: The ISB is (in fact) the same basic 5.9L that Dodge used in trucks for years. That ISB design goes back a few years earlier and it is still in production in medium duty trucks. In most situations, the manifold and flange are identical regardless of the application. The exhaust manifolds are prone to cracking. Make sure that isn't the issue. In some HD applications the rear manifold bolt will pop its head allowing a leak as well. Either way, there are no exotic weird parts. Its a Cummins 5.9. Period. If its a cracked manifold, don't try to weld it. Some guys have welded them with mixed results. The aftermarket has solved the issue with a 3-piece exhaust manifold, but its pricey. If its cracked, just replace it with a junkyard piece.

That's what I was hoping to hear. If memory serves, the manifold seems fine, and it seemed like it a two piece.

So do these studs actually break? They didn't look bad.

tuna55 wrote:

curtis73 wrote: The ISB is (in fact) the same basic 5.9L that Dodge used in trucks for years. That ISB design goes back a few years earlier and it is still in production in medium duty trucks. In most situations, the manifold and flange are identical regardless of the application. The exhaust manifolds are prone to cracking. Make sure that isn't the issue. In some HD applications the rear manifold bolt will pop its head allowing a leak as well. Either way, there are no exotic weird parts. Its a Cummins 5.9. Period. If its a cracked manifold, don't try to weld it. Some guys have welded them with mixed results. The aftermarket has solved the issue with a 3-piece exhaust manifold, but its pricey. If its cracked, just replace it with a junkyard piece.

That's what I was hoping to hear. If memory serves, the manifold seems fine, and it seemed like it a two piece. So do these studs actually break? They didn't look bad.

Hey Curtis, did you get my PM?

Five hours, one broken bolt (it was near the cracked portion of the manifold, it cracked after being loosened three turns and was easy to run a die over it and double nut) without any cutting and it was done. FIL is happy, and my back doesn't hurt too much. $400 in parts. Not too bad, eh?

Not bad at all. Much less than many and many thousands.

I have a camping trailer- and a little one at that. I have no interest in owning a motorhome, unless it were one of those awesome GMC deals with the 455 old toronado FWD setup. If you're going to get 3 mpg, you might as well do it in style.

Great work! Can you guess what you saved him? I'm curious... $3k maybe?

I do the same thing on a much smaller scale. Last time my dad threatened to get a new $2,500 riding mower I lifted the seat and tightened up the battery cables two minutes before he left for the mower store!

ebonyandivory wrote: Great work! Can you guess what you saved him? I'm curious... $3k maybe? I do the same thing on a much smaller scale. Last time my dad threatened to get a new $2,500 riding mower I lifted the seat and tightened up the battery cables two minutes before he left for the mower store!

Cummins Northeast quoted him $10k to get started.

For the record, Cummins will sell direct. Just go to their nearest truck engine service centre with the engine serial number and the CPL number and show them on their computer screen the part you want. I had a cracked fuel rail on my 6.7. $1400.00 from Dodge and $400.00 including airfreight from Cummins.

bearmtnmartin wrote: For the record, Cummins will sell direct. Just go to their nearest truck engine service centre with the engine serial number and the CPL number and show them on their computer screen the part you want. I had a cracked fuel rail on my 6.7. $1400.00 from Dodge and $400.00 including airfreight from Cummins.

I did buy the parts from Cummins, that was the $400. The counter jockey's were slower-than-molasses and kid of jerks, unfortunately.

tuna55 wrote:

ebonyandivory wrote: Great work! Can you guess what you saved him? I'm curious... $3k maybe? I do the same thing on a much smaller scale. Last time my dad threatened to get a new $2,500 riding mower I lifted the seat and tightened up the battery cables two minutes before he left for the mower store!

Cummins Northeast quoted him $10k to get started.

They didn't want the work.

tuna55 wrote: I did buy the parts from Cummins, that was the $400. The counter jockey's were slower-than-molasses and kid of jerks, unfortunately.

That sucks. The service center near me was always pleasant to deal with. Plus, the service side was often open late so if I bought and paid for something over the phone, I could stop by after work and pick up the part at like 8pm or so.

Ian F wrote:

tuna55 wrote: I did buy the parts from Cummins, that was the $400. The counter jockey's were slower-than-molasses and kid of jerks, unfortunately.

That sucks. The service center near me was always pleasant to deal with. Plus, the service side was often open late so if I bought and paid for something over the phone, I could stop by after work and pick up the part at like 8pm or so.

Calling them ahead, letting them know when I was going to pick up the parts netted me waiting in line behind one guy while one counter guy chatted with him about VW buses for about 20 minutes. Then the counter guy helped the VW bus guy take his stuff to his van for 10 more. Then he proceeded to do everything but help me. Chat with the warehouse people, wander over to the drinking fountain, scratch himself, etc. When he finally talked to me, it took 10 more minutes before they found the guy who I talked to on the phone who never even pulled the parts out.

It was awful, I was already late for a kids Dr.s apt so I went back the next day AFTER they called to confirm that they had the parts in a box with my name on them.

And they put two bolts in instead of ten, and forgot the two weirdo bolts.

45 minute drive one way.

In reply to tuna55:

Damn... whereas I'm so close to the one by me the car isn't even warmed up when I pass it.

For future reference I have a friend that works for Cummins Northeast, and I maintain a whole lot of Cummins engine gensets at work, so I have access to parts and knowledge. By no means am I an expert, but my friend is, and I know a fair amount about the B, and C-series Cummins engines. You can get any part for them I have found by providing the engine serial number. I have had similar experiences with Cummins Northeast, but now when I go in I tell them that my friend sent me in, and they know who he is so they seem to help a lot more.