best engine

[newmar40jw]

What is the better engine in motor homes, 2000'-2008' C7 Cat or Cummins, most dependable holds up the best?

[Cloud_Dancer]

For me, it was a no-brainer. When I odered my 2003 Dutch Star, paying for the optional Spartan/Cummins package was well worth it. Significant more torque from the engine, plus the other features of the Spartan chassis proved to be a good choice. I just wish I had known about the design deficiency in the roof.

[SidecarFlip]

jplante4 wrote:

Isaac-1 wrote:
One thing to keep in mind is that Cat has been out of the on road diesel engine business for almost a decade, so finding shops to work on them will get harder and harder every year as more and more are retired out of the commercial fleets.

However, CAT continues to build construction equipment with the same engines and there are plenty of shops that service these vehicles. I take mine to an equipment service location for CAT specific service (valve lash adjustment) and there are always buses or older trucks in the bays. They even repainted my valve cover CAT yellow.

Caterpillar Engine has a very devout following and will be a presence in the on road market for a long, long time because the pre-tier 4 engines are efficient and reliable.

Factory certified Caterpillar engine shops are country (world wide actually). Here in this part of the states, Williams is the place to go.

[jplante4]

Isaac-1 wrote:
One thing to keep in mind is that Cat has been out of the on road diesel engine business for almost a decade, so finding shops to work on them will get harder and harder every year as more and more are retired out of the commercial fleets.

However, CAT continues to build construction equipment with the same engines and there are plenty of shops that service these vehicles. I take mine to an equipment service location for CAT specific service (valve lash adjustment) and there are always buses or older trucks in the bays. They even repainted my valve cover CAT yellow.

[SidecarFlip]

Actually an ACCERT engine is ok. They have spacer plate issues but only about 100,000 miles and I've seen some go 250 without any issue, The lower ends are full skirted and very strong. The compound turbo assembly is pretty expensive to replace but I've never seen any with turbocharger issues other than the waste gate actuator which is cheap and easily replaceable.

The big 34 series engines that you would never find in an RV are the ones with the issues and why CAT got out of the on road business. They just loaded up a reliable workhorse with too much emissions hardware and ruined it.

I would not run from an ACCERT at all. You'll never get enough mileage on one to experience issues.

[Ivylog]

2003 and older, either, 2004+ Cummins as you do not want an Accert Cat engine. Google "Acert engine problems" and poor mpg. The bigger the engine theme bigger the problems.

[Isaac-1]

One thing to keep in mind is that Cat has been out of the on road diesel engine business for almost a decade, so finding shops to work on them will get harder and harder every year as more and more are retired out of the commercial fleets.

[SidecarFlip]

Chris Bryant wrote:
Either one will outlast the rest of the chassis.

That too. The chassis will corrode away before the engine fails.

[Chris_Bryant]

Either one will outlast the rest of the chassis.

[SidecarFlip]

My only comment is a CAT will cost you more for consumable parts (filters and such) than a Cummins will but the new generation ISX engines are having turbo issues and had fuel pump (lift pump) issues as well.

Don't know about longevity but I do know that both Cummins and Cat have derated their warranty periods. My opinion is, no smog motor (Tier 4 final) will last as long as a pre Tier 4 engine will. They run too hot and heat kills an internal combustion engine.

I wouldn't be concerned about any issues too much as most RV's with diesel engines never see anywhere close to enough miles to have issues out of warranty.

[Old-Biscuit]

Either IF they have had normal routine maintenance done