Cummins Powered Motorhome

[mberry]

My parents just purchased a 2004 Winnebago class A diesel pusher motorhome. It has a 300HP 5. 9 Cummins diesel and a 6 speed Allison trans on a Freightliner chassis. It has, I believe, 23K miles on it.

My dad would like to get a little more power out of it. My question is, is it "chippable", or is there a safer way to increase the power? Are there injector and turbo options available? What about the transmission needing to be upgraded to handle the extra power?

I have advised him to wait until he drives it towing his 5K lb boat and or 3500lb car over Donner pass to our home before he decides whether it "needs" anything done to it. I have also advised him to change to synthetic fluids everywhere since he isn't very good at keeping to regular maintenance intervals and this was a huge investment for them. I am recommending Amsoil.

More questions:

How much oil does this configuration hold? I think it's more than the 3 gallons our trucks take but I honestly don't know.

How much auto trans fluid does the trans hold?

Anything else I am missing here?

Thanks everyone.

 

[Skydiver]

Are you sure it's your Dad that wants more power? J/K

Sounds like a nice rig. Have him check the fuel mileage while it is stock.

Could need a fuel filter if the power is down.

The full synthetic is the was to go. I just change my oil when the odometer rolls over 10K. He might first try 5K with an oil analysis and then go to 10K if the oil checks out fine.

Sorry, can't answer the other questions and I refuse to guess.

 

[jelag]

He's got the same 6bt in his motorhome we have in our trucks with some software changes to help it work with the Allison Transmission... . I don't see why any of the performance kits and injectors won't help...



My neighbors CAT in his class A by the same company hold 22 quarts in the engine and close to that in the Allison... he needs to check his chassis manual... . if he doesn't have one go to Freightliner and order one... .



BTW - we found my neighbors water heater had a hot water loop off the engine to heat hot water for the coach and that same water later went up front to the defroster and back to the engine... . if he has problems with the defroster and no heat its from an air bubble... .



Down on the frame rail hidden along side the transmission in the hot water return line is a water gate valve and petcock... . when the defroster air locks, and it will, if its run low on water in that plastic 5 gal resorvor on the radiator... you close the gate valve when the engine is hot and open the pet cock... and let it run for at least 20 - 30 min while it burb's its self, usually 5 - 7 gals of coolant... we caught it in a 5 gal pail and ran it back into the overflow tank... . and my 83 year old neighbor now watches that tank... . they like to seam leak... . very poor design... .

 

[MMeier]

You sure its a 5. 9 and not the 8. 3 ?

 

[mberry]

Thanks everyone. Yes he wants more power but I don't think he understands how much better it's going to be than their class a 460 CI Ford powered gas engined one they replaced. Time will tell.

Thanks for the info Jelag. I have passed that along. BTW, it holds 14 quarts of engine oil and all the filters.

Yes he's sure it has a 5. 9L and not an 8. 3L. He has all the manuals that came with it.

They are selling the their 31. 5 feet, '97 Sea Breeze with a little over 19K miles on it if anyone may be interested.

 

[Gary - K7GLD]

They will really appreciate the diesel power/economy upgrade over a BB gasser - sure wish we had an engine/transmission setup in our '88 Winnebago-454 GM gasser like we do in the '02 Dodge we use to tow our KIT 5er! About the same GWR for both setups - but a WORLD of difference in power/economy!

 

[mberry]

You got that right Gary!

 

[EricBu12]

A while back in the Conversion area, a member converted his 40' Pace Arrow Limited from a 460 Ford to a 12 valve Cummins with an Allison transmission. . Last I heard it was running great... Wonder what mileage he is getting. . he was thinking he might get 10... and 1000 miles range

 

[mberry]

That's a good question. I would be curious to know as well. It was also something my dad was considering, but they wanted something newer and something with a slide.

 

[zb39]

If it was an 8. 3 ISC he would not be asking for more power. Spent 6. 5 years driving one, they are mountain masters. Just got my new to me 10. 8L ISM, now I know what real power is. A real 2 spd jake brake, fun to listen to and works so well!

 

[mberry]

That's very true zb. I actually wish it was an 8. 3 instead of the 5. 9 but I don't think they will have any problems with the power they have. They did a 100+ mile shakedown cruise Sunday afternoon and he said it ran and rode great. No problem with power but he hasn't taken it up into the hills yet. He did say there were lots and lots of rattles though. Both of us guessed that those will be reduced once they get the cabinets and storage spaces filled with stuff from the old one. Then he will be able to track them down easier.

He did have to put in a new house water pump though. The old one wasn't pumping much at all. He replaced the 2. 8gpm for one of the fancy new 4 gpm electronic units.

 

[AClayton]

Banks,Edge and BD Power have MH mods.

 

[Gary - K7GLD]

That's a good question. I would be curious to know as well. It was also something my dad was considering, but they wanted something newer and something with a slide.

I really like the layout, size and overall build quality inside and out, on the '88 Winnebago we just got. If we were a bit younger, with more RVing miles ahead of us, I'd really love to do the Cummins conversion to ours - the locating a suitable engine/transmission setup wouldn't be all that hard - but finding an experienced QUALITY engine swapper for the swap and multitude of related issues and problems would be the hard part.

 

[AClayton]

I'm not sure the front-end of your MH would handle the added weight of the Cummins and extra hardware. Heavier coil springs would definitely be necessary as well as upgraded shocks. Most people would not like the noise up front but me..... I wouldn't mind at all listening to the turbo sing while negotiating steep grades. Probably get about 13 or 14mpg also.



Alan

 

[mberry]

Thanks. Looks like the Edge EZ is an option without doing any hardware changes.

 

[mberry]

Well, the folks are taking a trip to Arizona to visit Dad's brother for about 10 days. I'll report back his fuel mileage numbers he reports and anything else he may have a question about.

I'm looking forward to him telling me how nice it was going up the hills.

 

[mberry]

The folks made it to AZ just fine. No problems, except there is a buzzing from some kind of pump that sounds like it's coming from the dash. It comes on with the key, not from any switches in the coach itself. Long story short, after a while it shut off. Any ideas what that might be so I can pass it along?

Another strange thing happened while I was down there. There was a very foul smell in the coach anytime it was closed up for a while. My parents thought that it was from the propane tank running empty. Someone also suggested it was a bad pilot valve on the oven. My initial thought was it was sewer gas from a plugged up vent since it didn't smell like propane at all.

So I started to do some troubleshooting. We poured another measure of chemicals into the black holding tank. No difference after a while. The smell would go away if the door was open, even for a short time. I got the ladder and pulled the vent cap off to see if it was plugged with some kind of nest. Nothing. Then I checked the holding tank drain area. Clean as whistle but it did have the strong smell there as well. So after about 1. 5 hours of looking around and crawling under the MH, the wind really started to blow. Then the smell really started coming from outside and from places and directions it shouldn't have. Dad kept saying that it was the wind blowing it down from the vent on the roof. I wasn't convinced so I let my nose guide me.

Long story longer, I found the source and was more than a little surprised. Turns out it was a bad house battery boiling away in the battery compartment. I could hear it boiling and the smell was by far the worst in this spot. What surprised me though, was that these gases were getting into the coach somehow from a well vented exterior compartment. Anywho, they replaced both house batteries under warranty since they were barely more than a year old, Interstate deep cycles with new ones and no more smell, and better performance from the batteries. I just hope that this isn't an inverter/charger problem.

 

[mberry]

So, the folks made the trip ok. Had some damage from the severe winds from last weeks' storm that tore the satellite dish off the roof. No other damage that I know of.

They reported just over 8MPG for the trip.

 

[Skydiver]

Good deal mberry! Sorry about the wind damage.

That sulfuric acid vapor is very corrosive. Might want to spray some WD-40 on the nearby electrical components. I would recommend installing a type of smart charger. Those old style MH chargers are known to destroy batteries.

At what speed was he getting 8mpg?

 

[mberry]

Skydiver,

It was bound to happen sooner or later. At least it wasn't here so there isn't any reason for them to not come and see their grandkids. Good idea on the WD40. I'll pass that along.

As for the "old style MH chargers", it's a 2004. Does it really have an "old style" charger? It has what appears to be a very sophisticated power monitoring system in it. I personally think the battery went bad simply due to lack of use and sitting there for over a year, or was bad from the factory. Time will tell though since it's got two brand new house batteries now. If one of them fails in the next year or so, it may be time to have the charger checked out.

He told me he was doing 65-67mph on the flats when they checked the mileage at their first fuel stop. I think their first stop was Bakersfield or somewhere close to it. There are a few hills on I-5 south from Sac to SoCal but nothing that would really impact fuel mileage until you get to the Grapevine.