Cummins ISX broken valve in #6

[dsavage74]

I am going to pick up my coach once again due to failure of I S X 650
This shoud be a class action lawsuit
The valve gets eaten by acid from the emission system. New valves and heads supposedly correct the problem. Now I find out new pistons with a scrapper ring are also TSB.
DOES IT EVER END WITH Cummins?
I would like to know if after the fix how many miles have you gone ?
Dave Savage

[Mr_D]

Originally Posted by Mark D

Confirmed, valve failure on #6.Attachment 221234

Well, kind of hate to say it but "welcome to the club".

[Mr_D]

Originally Posted by dsavage74

I am going to pick up my coach once again due to failure of I S X 650
This shoud be a class action lawsuit
The valve gets eaten by acid from the emission system. New valves and heads supposedly correct the problem. Now I find out new pistons with a scrapper ring are also TSB.
DOES IT EVER END WITH Cummins?
I would like to know if after the fix how many miles have you gone ?
Dave Savage

I'm up to about 8,000 miles since my rebuild and I only got the first iteration of parts so it'll probably fail again.

[Mr_D]

Originally Posted by Mark D

And all in #6. I think it's due to the EGR cooling, #6 is the hottest.

Cummins says it's acid etching that weakens the valve and the heat helps weaken the remaining structure.

[Mr_D]

Originally Posted by 08Navigator

Ask them if they can give you a reason that #6 only fails prematurely on the RV's? I assume you have low mileage? Same EGR system on a truck, I assume?

Truck engines are run hard and often which burns the acid off. MH engines are run much less, under light loads and sit for more than time. That lets the acid do it's work.

[palehorse89]

It still boils down to Cummins using cheap inferior valves/seats in a spread of years I believe Mr. D
The new components will live in the same atmosphere .......

[Mark D]

Originally Posted by dsavage74

I am going to pick up my coach once again due to failure of I S X 650
This shoud be a class action lawsuit
The valve gets eaten by acid from the emission system. New valves and heads supposedly correct the problem. Now I find out new pistons with a scrapper ring are also TSB.
DOES IT EVER END WITH Cummins?
I would like to know if after the fix how many miles have you gone ?
Dave Savage

I put a link to a class action law firm earlier in this thread. Shoot them an email, I did.

[2-Nickels]

I have put 13,000 miles on since the rebuild and am about to add another 3000 starting mid month.

[randomledder]

If you do end up taking .010 off the head the injector protrusion will need to be checked. Don’t worry about the cam bearings as I previously stated they always look like crap. As for the rods and mains I have seen them with well in excess of a million miles and they pretty much look the same as when they went in. There a very hard bearing. Not like the old 855 and N14 days. Bearing rolls at 5000 hours is a thing of the past. There hardness is great for longevity but any sloppy work getting dirt into the engine especially through the main oil gallery at the oil cooler will tear out #4 rod and main. Just my 2 cents. Take it for what it’s worth.

[08Navigator]

Originally Posted by randomledder

If you do end up taking .010 off the head the injector protrusion will need to be checked. Don’t worry about the cam bearings as I previously stated they always look like crap. As for the rods and mains I have seen them with well in excess of a million miles and they pretty much look the same as when they went in. There a very hard bearing. Not like the old 855 and N14 days. Bearing rolls at 5000 hours is a thing of the past. There hardness is great for longevity but any sloppy work getting dirt into the engine especially through the main oil gallery at the oil cooler will tear out #4 rod and main. Just my 2 cents. Take it for what it’s worth.

Thank you for your input! I have the little plugs that came in the gasket kit shoved in the oil jacket holes to crap from entering there. Looks like I had a good 1/32 at the injector sleeves...but will keep my eye on what the machine shop does! Thanks again!

[08Navigator]

Important for you DIY's...I was thinking one thing and typed another thing below....I mention oil and antifreeze mixing...my error...The benefit of my gadget is that when the cooler fails. and it will, they all do, you will not have anti freeze being sucked in the cylinders...the oil/anti freeze issue is a whole other topic.Sorry!!

Originally Posted by 08Navigator

They haven't set up on the mill yet to measure...I wouldn't think anymore then .010" to clean it up...at least I hope not...but it needs to be checked to be sure. It's a huge casting , can't imagine it's warped....but I want it checked cause I don't want to go on another tow it home vacation again. I am checking and double checking everything and anything. Worrying a little about the cam bearings now, the center bearings are the worse...which makes me think about rods and mains...I wish I knew what was typical of these engines...if it was one of my racing engines I would be in a panic and tearing it all the way down...still thinking...going open up the oil filter and take a look...maybe over thinking the whole thing...I dunno

Been fooling around with a gadget I call it the "Eliminator". It eliminates the EGR, to be used in the event someone would want to use the ISX for off road competitions. The Eliminator ends the worry of anti-freeze / oil mixing, added bonus, lot less parts in the engine compartment and a 100 pound diet. Why my concept verses the after market delete kits, mine keeps the water flow to the oil cooler cavity. Since 73% of the water pump output goes to the EGR and heat has proven to be a factor in the engine, last thing I wanted to do was alter water flow. Using two JIC fittings and bits and pieces that come from a factory EGR, a little TIG welding...add a braided line, a fiberglass heat wrap and you got yourself an Eliminator. Look at that monstrosity they had bolted on there!

[palehorse89]

Originally Posted by 08Navigator

Important for you DIY's...I was thinking one thing and typed another thing below....I mention oil and antifreeze mixing...my error...The benefit of my gadget is that when the cooler fails. and it will, they all do, you will not have anti freeze being sucked in the cylinders...the oil/anti freeze issue is a whole other topic.Sorry!!

So your new setup will put the outlet of the oil cooler back into the cooling system return?

[08Navigator]

Originally Posted by dsavage74

I am going to pick up my coach once again due to failure of I S X 650
This shoud be a class action lawsuit
The valve gets eaten by acid from the emission system. New valves and heads supposedly correct the problem. Now I find out new pistons with a scrapper ring are also TSB.
DOES IT EVER END WITH Cummins?
I would like to know if after the fix how many miles have you gone ?
Dave Savage

Man after my own heart! That was my first post ( class action) when I joined this site...So far only a few people with failures have indicated interest...I am sure there are hundreds but legal wont touch it with less then 100 plaintiffs. I am taking Cummins to small claims court...I could be awarded up to $12,000, which should more then cover my costs. If I don't win there I will have my legal sue them for the value of a replacement coach and matching trailer..as for I am terrified to drive it...when the engine stops I have no hydraulic pressure for steering. @ well over 80,000 pounds /85 feet long...with two race cars and a trailer...I could kill a family in seconds...this is not a Joke. I NEED a reliable engine.
I have been working on a preparing a stock holders proposal, I am suggesting that they exit the over the road market place, no different then CAT...I am worried about my investment, if and when the defective engines start to kill people. Keep you posted on the indoor sports when the punches start.
As for how long will the fix last? This is my own personal thoughts .. I am by no means a diesel mechanic...this is my first rodeo with a diesel. I believe there is truth to the concept of the valves pitting and the pits starting cracks ...that's elementary. I am sure the over the road guys have similar....all of my valves have the same pitting , one has to ask why number 6 cylinder...as mentioned before I firmly believe there is a situation exclusive to the RV's that make #6 fail...Perhaps the new valves from Cummins will fix the issue ... however I am taking anything suspect and anything else I feel could fail out of the equation. I believe without changes, the #6 intake will fail and fail and fail.... Just my 2 cents.

[Mark D]

Originally Posted by 08Navigator

Man after my own heart! That was my first post ( class action) when I joined this site...So far only a few people with failures have indicated interest...I am sure there are hundreds but legal wont touch it with less then 100 plaintiffs. I am taking Cummins to small claims court...I could be awarded up to $12,000, which should more then cover my costs. If I don't win there I will have my legal sue them for the value of a replacement coach and matching trailer..as for I am terrified to drive it...when the engine stops I have no hydraulic pressure for steering. @ well over 80,000 pounds /85 feet long...with two race cars and a trailer...I could kill a family in seconds...this is not a Joke. I NEED a reliable engine.
I have been working on a preparing a stock holders proposal, I am suggesting that they exit the over the road market place, no different then CAT...I am worried about my investment, if and when the defective engines start to kill people. Keep you posted on the indoor sports when the punches start.
As for how long will the fix last? This is my own personal thoughts .. I am by no means a diesel mechanic...this is my first rodeo with a diesel. I believe there is truth to the concept of the valves pitting and the pits starting cracks ...that's elementary. I am sure the over the road guys have similar....all of my valves have the same pitting , one has to ask why number 6 cylinder...as mentioned before I firmly believe there is a situation exclusive to the RV's that make #6 fail...Perhaps the new valves from Cummins will fix the issue ... however I am taking anything suspect and anything else I feel could fail out of the equation. I believe without changes, the #6 intake will fail and fail and fail.... Just my 2 cents.

I asked the question why always #6 on a ISX page. Most answers pointed to the EGR cooler. From what I gathered due to the design #6 gets the least benefit from the cooler so the intake gets beat on the most.