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jpsageusa · 01-11-2019, 10:10 AM

My 2006 ISB 5.9 CR failed at 56K miles. A part of the valve train broke, got caught under a rocker arm and that caused a valve to strike a piston. Engine change!

What follows is general ramblings to start a thread about cause, effect and prevention.

A front office person at the Peterbilt garage doing the work happened to be on the phone with a Cummins rep and asked about the early failure when the class 5 trucks with this engine rarely have this type of problem. The response was that the long storage times of RVs are hard on the engines. Hmmm...

In my case the tech believes that an injector was the original culprit. He believed that the injector was pouring too much fuel and the heat was transmitted into the head causing the valve train to fail.

I have also read that running the engine at idle does not get the engine to operating temperature.

I plan to ensure that the fuel tanks are always full when I put it up in the garage and I plan on getting it out on the road at least once a month.

Can the long storage allow the oil in the head to dissipate and cause excess friction on start up?

And finally would an EGT gauge detected the problem before I ended up on the side of the road. Cummins does not use EGT on their medium duty engines.

John.

tom chelbana · 01-11-2019, 10:48 AM

As a 25 year service/repair owner for both gas and diesel vehicles, auto tech. instructor for 14 years, 20 years building and racing engines and 22 years of Cummins diesel ownership I don't believe the information your received. Valve train failure usually caused by broken valve springs, adjustment issues, faulty parts and lack of oil. I don't think EGT, over fueling and storage time caused your valve train problem. What were the parts that were damaged? How did the rest of the valve train look?

alpenlite29 · 01-11-2019, 03:14 PM

I WILL JUST SAY THIS The cummins guy....doing phone fixes...is bull. And if it is happening Cummins should step up to the plate and fix it. To many generators..fire trucks and other heavy equipment is parked in the winter months...and the valve train does not fall apart? I will speculate some type of parts failure occurred....which I am breaking my own rules. Unless a failure analysis was done...it is just a way to pass this own to the customer.

jpsageusa · 01-11-2019, 09:36 PM

Quote:

Originally Posted by tom chelbana

As a 25 year service/repair owner for both gas and diesel vehicles, auto tech. instructor for 14 years, 20 years building and racing engines and 22 years of Cummins diesel ownership I don't believe the information your received. Valve train failure usually caused by broken valve springs, adjustment issues, faulty parts and lack of oil. I don't think EGT, over fueling and storage time caused your valve train problem. What were the parts that were damaged? How did the rest of the valve train look?

Good question. I didn't get to see the underside of the head. But the tech said it was a non-valve train part that ended up under the lifter. I will try and get a picture of it tomorrow. I did get to look at the block and you can see the valve impression on the piston.

jpsageusa · 01-11-2019, 09:43 PM

Quote:

Originally Posted by alpenlite29

I WILL JUST SAY THIS The cummins guy....doing phone fixes...is bull. And if it is happening Cummins should step up to the plate and fix it. To many generators..fire trucks and other heavy equipment is parked in the winter months...and the valve train does not fall apart? I will speculate some type of parts failure occurred....which I am breaking my own rules. Unless a failure analysis was done...it is just a way to pass this own to the customer.

We have Good Sam "extended warranty" and they are picking up a large portion of the tab. The engine is many years out of Cummins responsibility. But the garage (a Peterbilt facility) did suggest that I go to Cummins and see if they would pick up some of the remaining cost. Good Sam would only cover a Rivia replacement engine and I am paying the difference for a Cummins reman.

I am retired and can spend five weeks in a motel but can you imagine someone who has to face this kind of downtime.

Mr_D · 01-11-2019, 09:44 PM

Well, at least it's not an ISX valve failure.

alpenlite29 · 01-12-2019, 10:03 AM

Cummins engines are designed to run roughly 500,000 miles. My experience has been if a piston and valve collide, The engine has over reved...or the piston/valve timming sequence has failed. OR a Cummins part failure in the valve train, broken part. Just experience talking as I can't see your engine. When going off of hills or people down shifting into a lower gear, may cause a lower rpm diesel engine to NOT be very FORGIVING!...I think the word is #KAAAPOWWW! The worst answer you will ever get from anyone when asking about something warranty is "NO".... Ask Cummins for a Product or manufacturers failure adjustment. Good Luck

Mr_D · 01-12-2019, 10:09 AM

When my ISX failed for the second time Cummins did pay $10,400 of the over $33,000 bill. Doesn't hurt to ask.

lwmcguire · 01-12-2019, 10:25 AM

Starting a cold diesel engine is where the most wear and tear comes from. Back in the less than 50 cent diesel days we let the tractors and trucks idle all day long in cold weather to avoid cold starts and to have a nice warm cab

I looked at a couple rigs that had set on a dealers lot for months. First think the salesman said was we come out and start the engine and generator up every week for 15 minutes

Didn't say anything to him but they were keeping the batteries up but not getting anything warm enough to do any good and putting a lot of wear and tear on both

This was through the winter months so they were many cold starts

The engines should be able to handle many cold starts, it just wears on them faster so I think it is best to not start them unless you are going to load and high idle to truly get them warmed up to operating temperature

As far as your failure I agree with the other posters completely

Ray,IN · 01-12-2019, 09:22 PM

I agree with Tom Chelbana,

Todays Cummins diesel engines(within the last 10 years at least) have a delayed ignition (not correct term) it will not open the fuel solenoid until oil pressure is detected after the starter in engaged. This is to reduce the cold startup effects.
FWIW, our MH had sat parked in a barn ignored for 6 years due to owner being too ill to travel. We haven't had any negative effects of that "long-term" storage.