Community Forums

Ted Lambert · 04-21-2016, 08:31 PM

I would like to hear from people who have a Cummins 5.9 in a 34ft coach.
The usual questions power etc.
Anything good or bad would be appreciated.

We found a low miler at a good price, but not sure about the power as it seems small. However my 3/4 ton Dodge would pull a 35ft tt with no problem.

kustom · 04-21-2016, 08:33 PM

ours works good

WILDEBILL308 · 04-21-2016, 08:59 PM

What year? What HP is it tuned to?
Bill

Dutch Star Don · 04-21-2016, 10:02 PM

You may not be able to climb a grade as fast as others, but you'll be able to run on flat ground as fast as anyone else. You need to decide if that will be an issue for you. You should be aware that often, the ISB is mated to an Allison 2500, which prevents you from adding any power upgrades to the ISB. When mated to an Alison 3000, there are some changes you can make. Something to think about!

Skip426 · 04-21-2016, 10:31 PM

the 5.9 Cummins is , arguably the fuel mileage king when it comes to motor homes. They may not be the fastest up the hills , but they will get you where you want to go, at the best cost per mile for fuel.
As mentioned you have to look at the whole drive line , transmission, rear gear ratios, and weight of the coach.
100 lbs of GCW, coach and toad , per engine HP is a good target.
I've been 5 years running at 107 lbs per HP and doing fine.

Dennis_K · 04-22-2016, 09:20 AM

I drove a 2003 34' Bounder with a 300hp 5.9 for 9 years and 40,000 miles. Pulled a 6500# trailer most of the time. While it would have been nice to have more power I never had a problem.

alpha99 · 04-22-2016, 11:09 AM

It's all about torque, not hp.

TLGPE · 04-22-2016, 12:26 PM

My '94 Dolphin weighed in at about 20000#. It was rated at 230HP. It ran really well on the road, and yes, it did give me 10 to 11 MPG. Mine had the waste gate valve hung open and would not pull well at the start, but at speed in the mountains it would keep up with any heavy vehicle traffic.

Tom

Geaux Tigers · 04-22-2016, 05:42 PM

Our previous MH was a 1997 Kountry Star 34' Class A with the mechanical 12 valve 5.9L Cummins mounted in the front so it was a "diesel puller". The original Allison 4-speed transmission had been replaced by a Ford 4-speed AT (same one used in school buses and garbage trucks) by the previous owner. He had also changed something in the fuel injection pump to boost the HP to around 275HP. The injection pump upgrade was a common one for those mechanical 5.9's. We were very pleased with its performance. I could count on 10.5MPG towing our VW Beetle and we made numerous trips to the Smokies and to Michigan from Louisiana. We would routinely pass 18 wheelers going up the steeper grades.

------ Jim

Ted Lambert · 04-22-2016, 06:11 PM

Thanks for the replies. It is a friend that is looking into it and he has no mechanical knowledge.
Thanks for the replies.
What I know about the 5.9 is they seem bullet proof.

Oilbrnr · 04-22-2016, 06:44 PM

Quote:

Originally Posted by narampa

Thanks for the replies. It is a friend that is looking into it and he has no mechanical knowledge.
Thanks for the replies.
What I know about the 5.9 is they seem bullet proof.

They did have dowel pin issues I *think*. Google it. Fairly easy fix if caught before failure if I remember correctly.

Hooligan · 04-22-2016, 07:19 PM

Previous MH, 36ft Diesel pusher, (2000 GeorgieBoy Landau) 260 HP Cummins ISB (5.9) Consistently 11mpg sometimes 12. Never felt underpowered. On steeper grades where my speed dropped, so did the OTR trucks. Bought new and traded last summer, 15 years. Most of the areas visited on my avatar map were in that MH.

The dowel pin issue seems to have been with the earlier 5.9's and I have heard no recent reports of those failures. I had heard that the electronic 5.9's (ISB's) did not have that problem.

noserider · 04-22-2016, 07:21 PM

I have the 24 valve 5.9 ISB 300 Hp. My rig weighs in around 25K and I pull a 5k toad. Acceleration with or without the toad from zero is weak but other than that I have been very satisfied for bang for the buck and mileage.

Wdebarmore · 04-22-2016, 07:43 PM

I have a 5.9 160 horse mechanical. Coach weighs about 17k. It's fine on flat ground and moderate hills. Steep climbs will slow it down to 35mph. Can't really turn up the power due to the torque limitations of the tranny. All in all, it's OK. Get's me where I need to go at 10-11mpg. Engine has never had any issues since new..and that was many years ago.