Circa 2002-2004 Cat C7 Heui Issues

#1. The number of HEUI failures is not that high-- but those who have had it fail are the only ones who bring up the subject.

#2. To determine exactly what system a Caterpillar engine has one it (depends on ENGINE build date), call the Caterpillar RV Hotline with the Caterpillar engine serial number: 877 777-3126.

FYI, I would rather have a C7 over a Cummins B and would rather have the Cummins C or L over the C7. Size matters, particularly when it comes to torque.

As usual, Brett is right on. But basically, just about any Freightliner chassis coach built prior to around mid to late '03, is touting the 3126 version CAT. After around Sept or so of '03, the C-7 was introduced. There are three, over the road versions of the C-7. A 300HP, a 330HP and, a 350HP. All of them put out 860 ft. lbs. of torque.

The C-7 was not only used in motor home chassis's. That engine is in zillions of over the road trucks, delivery trucks, tractor-trailers, FIRE TRUCKS(many), cement trucks and more. No one on here (this site) knows the ratio of just how many C-7s have had HEUI issues, vs the total amount of C-7s produced and, are still putting thousands and thousands of trouble free miles on our roads.

As Brett stated, we only read on here about the infamous HEUI problems. And, how many is that, actually??? And, don't forget, Cummins has had its share of reliability issues too, on some of its series engines. Wrist pins, continuous blown head gaskets, and a few others come to mind on some of them. But, again, who knows just how many of the Cummins engines had those series problems?

So, pic your poison. Our coach, an '04 Itasca Horizon 36GD with the C-7 330HP CAT, has 63K on the clock and, is running down the road strong and healthy. We tow around 6500 lbs. worth of 2011 GMC Sierra Extended Cab 4x4 with a Rampage lift and, an '08 Honda GL 1800 Goldwing in the back of it. And that engine does great.

Keep the radiator and CAC fins clean, change your oil on time and regularly, and change your ONLY or, dual fuel filters and, that CAT will serve you well.
Scott

I also agree with Brett & Scott. I'm a retired trucker and Catapillar came out to our shop and told or mechanics to add 1 gallon of motor oil above full to all C-7 CAT engines to protect bearings inside the engine. The CAT people also said overfilling the crankcase will not hurt the engine. All of our C-7's were in delivery trucks. I prefer Cat motors over all others having driving them for 44-1/4 years OTR. The last CAT engine that I drove had inframe overhauls at 750,000 miles and 1,200,000 miles, and 1,300,000 miles after the 3rd inframe my boss sold the truck to a local ship hauler and that truck is still going up and down I-5 to this day and that speaks for itself.

the c7 that you need to avoid is the 2007 emission engine. this has a common rail fuel system the engine serial number will start with c7s cat could not make this system work reliably and they dropped out of the truck engine market when the 2010 emissions were required

Rooster. For MH's Cat has advised just the opposite. You must run less oil to prevent the slobber tube from spitting out the excess.

Moisheh

I have never seen anything from Caterpillar in writing suggesting either more or less oil than their specs call for. The only exception was some early 2000 models where they officially changed the recommended crankcase capacity-- reducing it slightly. When I do the Caterpillar Maintenance Seminars at the FMCA Conventions, I still use the old (and still accurate per Caterpillar) capacities.

Nor have I ever purposely over or underfilled ANY engine, gas or diesel. Cat or Cummins.....

Had my 2004 C7 heuipump and 6 injectors replaced (61k miles) this past winter. I've only recorded about 1K miles since but it hauls the hills stronger than ever.

Cost was $7500. Just FYI.

I would try to stick with inline 6s. I never like Cat C engines, IMHO they were built for boats and are a constant power rated engine and self destruct under the constant changes of throttle. I had 3406 Bs and Es and they held up for millions of miles.

Passin Thru wrote:
I would try to stick with inline 6s.

Not sure I understand. 100% of the diesel engines he could be considering whether Caterpillar or Cummins are inline 6s.

On Edit: BTW, I am not "pro" or "anti" either Caterpillar or Cummins.

Put 200,000 miles on Caterpillar powered DP's.

Current coach has Cummins ISL.

No problems with any of them. Just do basic Preventive Maintenance.

I had the heui pump go out at 42k. Limped home from death valley to LA area. I am at a few hundred shy of 80k now. Two months before the heui went out, I had it at a local dealer who changed the fuel filter. Didn't even bother to clean the mount, filter. I made a comment at the time. Some miles later the heui went out. Two versions what happened, 1 is dirt, then other is the pump shaft is too small and starts to cavitate, sending metal shards down stream to the injectors. It was fixed under warranty. I was told at the time there's an updated pump out there proving to be fine and the aftermarket has some good solutions as well. Needless tobsay, I do my own maintenance now unless time is a bother. I do know the old 7.3L powerstroke is heui and many of those less stout motors have 300, 400 k on them no pump change.

Fwiw if you find a coach you love but the number comes up with the old pump via cat, you could premptively change out the pump. Just price the change into your offer. I've heard it done for 1400-2k. Check your local shop first.

Good luck