Cummins ISX broken valve in #6

[Electra 225]

Oh really, guess I didn't know that, wow.
Yeah my experience has been with machines a few years older......and in addition regarding Deere tractors too, (550hp Deere engines).....we just kept em lubed up and breathing and go.

Thanks for the clarification.

[mackwrench]

My son is a regional rep for Deere.... Tier 4 emissions on farm/industrial equipment = pita

[pbensen]

Originally Posted by 08Navigator

I agree 100%..I stand corrected..I really thought it was the heat , best intentions, honestly. I hope I haven't caused anyone any work! I told ya I am not a mechanic!!

I do have a question...My engine had the same size coolant holes all the way down both sides of the block...you are saying you have seen them with different size holes in the rear?

I think the rust pits start the cracks, and the heat finishes the job..It could be as simple as the seats and valve angles get so pitted that the heat can not be transferred properly.. BUT that still doesn't explain why RV's?
Couple thoughts tho...I think if something went wrong with the engine brake, it wouldn't effect intake valves, nothing ever hit my pistons...The scoring of the liners is surely heat...maybe the motor is lean back there...but again why just motorhomes and #6?

Absolutely no offense taking...I am thrilled that you point out the fault in my theory before others took time to make changes...I really would like to solve the mystery...I am going to keep thinking....the answer is out there!!

How is your engine running now? Are you happy with how the repair came out? Where are you going on your first trip after the engine repair?

[08Navigator]

Extremely pleased with the way my ISX runs now, runs cooler..180-185 water temp range. The power is incredible!!. Its like I now own a high performance coach. Literally pushes you back in the seat, makes me smile! Throttle response far superior. Boost is down at 30PSI verses 38 factory setting, that's a significant reduction on stresses throughout. One particular hill near my home..coach used to pull it to top at 55mph...now 70MPH...there is not even a comparision! I used to think it ran good...NOW it runs good!!
Took it on 250 mile test run to mid state PA - across I-80 ran flawless, came home, checked oil...its still clear! no more of that black crap I used to see within miles of use.
Honestly, after being pissed at the thing...now I am glad it blew up, the coach runs so much better and I will now travel with piece of mind knowing the motor is in good working order. I bet now it will run 100's of 1000's of miles effortlessly.

As for my first trip, want to take one of my race cars and a couple harleys down to Palm Beach Fl. , issue is Girl Friend dumped my fat ass day after Christmas..guess she stuck around to collect the 2018 gifts..(or maybe she didn't like gifts, but I think she did...took em with her) then out the door...soooo now I am on the prowl for a new hottie to head south for a month or so.. this time around, no more redheads, looking for petite blonde, 45ish, no kids..something that fits nicely on the back of my Harleys....know of one send her my way!
Typically, you mention free trip...they come flocking...

Last girlfriend was more of PIA then the Cummins blowing up! (Marry me Marry me...I hate any girl you look at....don't talk to any woman ..don't talk about your deceased wife...I hate her too...god the crap I endured!)

Soooo... 2019 is kicking of to be a banner year...nice running coach and single!! Plus tons of opportunity in the Market!

Back to the coach.....it is important to note engine runs 10 - 15 degrees cooler...and I did NOT change the variable speed fan perimeters , the cooling system is simply significantly more efficient. It is also important to note, the coach is significantly louder, not inside, but it roars on the outside. If fact as I was charging the air conditioning...after a half hour or so, I put ear plugs in... The engine brake has also lost Appox. 25% efficiency. Anyway, I am thrilled and I now love my ISX!

[Mark D]

Originally Posted by 08Navigator

Extremely pleased with the way my ISX runs now, runs cooler..180-185 water temp range. The power is incredible!!. Its like I now own a high performance coach. Literally pushes you back in the seat, makes me smile! Throttle response far superior. Boost is down at 30PSI verses 38 factory setting, that's a significant reduction on stresses throughout. One particular hill near my home..coach used to pull it to top at 55mph...now 70MPH...there is not even a comparision! I used to think it ran good...NOW it runs good!!
Took it on 250 mile test run to mid state PA - across I-80 ran flawless, came home, checked oil...its still clear! no more of that black crap I used to see within miles of use.
Honestly, after being pissed at the thing...now I am glad it blew up, the coach runs so much better and I will now travel with piece of mind knowing the motor is in good working order. I bet now it will run 100's of 1000's of miles effortlessly.

As for my first trip, want to take one of my race cars and a couple harleys down to Palm Beach Fl. , issue is Girl Friend dumped my fat ass day after Christmas..guess she stuck around to collect the 2018 gifts..(or maybe she didn't like gifts, but I think she did...took em with her) then out the door...soooo now I am on the prowl for a new hottie to head south for a month or so.. this time around, no more redheads, looking for petite blonde, 45ish, no kids..something that fits nicely on the back of my Harleys....know of one send her my way!
Typically, you mention free trip...they come flocking...

Last girlfriend was more of PIA then the Cummins blowing up! (Marry me Marry me...I hate any girl you look at....don't talk to any woman ..don't talk about your deceased wife...I hate her too...god the crap I endured!)

Soooo... 2019 is kicking of to be a banner year...nice running coach and single!! Plus tons of opportunity in the Market!

Back to the coach.....it is important to note engine runs 10 - 15 degrees cooler...and I did NOT change the variable speed fan perimeters , the cooling system is simply significantly more efficient. It is also important to note, the coach is significantly louder, not inside, but it roars on the outside. If fact as I was charging the air conditioning...after a half hour or so, I put ear plugs in... The engine brake has also lost Appox. 25% efficiency. Anyway, I am thrilled and I now love my ISX!

I saw the same drop in temp with my new head. I know you did some mods but I have everything from Cummins and it runs cooler. I also noticed the engine runs better. It wasn't as dramatic as your experience, you may have needed some valve adjustment before the issue or maybe #6 had blow by etc. But I do notice the engine just seems tighter. Similar to a German v8 vs a US v8. They both make the power but the German v8 just seems tighter.

I am glad that you have have had good results. It sucks when you put all this work into something and you lack that sence of satisfaction after.

[pbensen]

Originally Posted by 08Navigator

Extremely pleased with the way my ISX runs now, runs cooler..180-185 water temp range. The power is incredible!!. Its like I now own a high performance coach. Literally pushes you back in the seat, makes me smile! Throttle response far superior. Boost is down at 30PSI verses 38 factory setting, that's a significant reduction on stresses throughout. One particular hill near my home..coach used to pull it to top at 55mph...now 70MPH...there is not even a comparision! I used to think it ran good...NOW it runs good!!
Took it on 250 mile test run to mid state PA - across I-80 ran flawless, came home, checked oil...its still clear! no more of that black crap I used to see within miles of use.
Honestly, after being pissed at the thing...now I am glad it blew up, the coach runs so much better and I will now travel with piece of mind knowing the motor is in good working order. I bet now it will run 100's of 1000's of miles effortlessly.

As for my first trip, want to take one of my race cars and a couple harleys down to Palm Beach Fl. , issue is Girl Friend dumped my fat ass day after Christmas..guess she stuck around to collect the 2018 gifts..(or maybe she didn't like gifts, but I think she did...took em with her) then out the door...soooo now I am on the prowl for a new hottie to head south for a month or so.. this time around, no more redheads, looking for petite blonde, 45ish, no kids..something that fits nicely on the back of my Harleys....know of one send her my way!
Typically, you mention free trip...they come flocking...

Last girlfriend was more of PIA then the Cummins blowing up! (Marry me Marry me...I hate any girl you look at....don't talk to any woman ..don't talk about your deceased wife...I hate her too...god the crap I endured!)

Soooo... 2019 is kicking of to be a banner year...nice running coach and single!! Plus tons of opportunity in the Market!

Back to the coach.....it is important to note engine runs 10 - 15 degrees cooler...and I did NOT change the variable speed fan perimeters , the cooling system is simply significantly more efficient. It is also important to note, the coach is significantly louder, not inside, but it roars on the outside. If fact as I was charging the air conditioning...after a half hour or so, I put ear plugs in... The engine brake has also lost Appox. 25% efficiency. Anyway, I am thrilled and I now love my ISX!

This fantastic news (about your coach)! You know that many people out here very much appreciate you sharing your findings/ experiences with us. I would think that with the many upgrades that you have made you should be seeing increased fuel mileage. Please let us know what your fuel mileage is when you take that beast on your first trip [emoji846].

[08Navigator]

Mark....I think the engine has tremendous potential...it just needs unleashed...I honestly don't remember it ever running anywhere near this good...I will know more once I put 25k behind it and start up some hills...but right now...very pleased...will let you guys know about fuel mileage...before I got 5.4 .. I will reset the trip thingy and see what it starts averaging now. Keep ya posted!

[1doodadd]

Ron, While running the overhead your adjustments on the Jake may have been a little out resulting in the lower results in retarding the exhaust valves. If not happy with it you can run 10000 miles and recheck the clearances. Just a thought

[05 American Eagle]

So you are saying the boost only makes it to 30 lbs? Mine is the 650 HP as well and regularly hits 40, seems odd that it would be lower.


If you race at West Palm or anywhere in Florida look me up, should not be hard to find. Look for the giant Crew Chief Pro on the side of the trailer.

[08Navigator]

Originally Posted by 05 American Eagle

So you are saying the boost only makes it to 30 lbs? Mine is the 650 HP as well and regularly hits 40, seems odd that it would be lower.


If you race at West Palm or anywhere in Florida look me up, should not be hard to find. Look for the giant Crew Chief Pro on the side of the trailer.

Don, I know of you...actually talked on phone.....I have your racing software on a altalab system. Boost change due to the fact I changed the turbo and the entire exhaust system...you retained all your original stuff right? Just did delete?
BTW..I have a whole pile of original cummins parts, due to the settlement agreement I had with them... brand new turbo in box, new actuator, new injectors, blah blah blah, big list.....maybe you want..I have no need, make a heck of a deal. You will love em if you ever need them!

[08Navigator]

Originally Posted by 1doodadd

Ron, While running the overhead your adjustments on the Jake may have been a little out resulting in the lower results in retarding the exhaust valves. If not happy with it you can run 10000 miles and recheck the clearances. Just a thought

I think that the change of the turbo is what made the brake not as effective...the original turbo would close up...the new one is fixed. It still works great tho, just not as effective as the Cummins variable turbo. Funny thing is, the new turbo seems to be a little hotter off the line then the old one...I am not a turbo guy...I know there is a ton to the concept...way beyond my capabilities....I am happy with my PDI billet unit...I recently saw a twin set up, and was like wow...should have gotten that...lol...it runs great...its a motorhome...I am happy!

[mackwrench]

That's Great news 08navigator....you have deleted the emission and will probably not have any more issue.
I'm certain the EGR, EGR cooler and related components are what causing these failures.

BTW, here's a pic of Mark Martin (Nascar guy) ISX twin turbo setup in his motorcoach

[08Navigator]

Originally Posted by mackwrench

That's Great news 08navigator....you have deleted the emission and will probably not have any more issue.
I'm certain the EGR, EGR cooler and related components are what causing these failures.

BTW, here's a pic of Mark Martin (Nascar guy) ISX twin turbo setup in his motorcoachAttachment 231280

Yep, that's exactly what I was looking at..appears they just added a PDI turbo inline with the stock Cummins unit...I bet that runs nice! I was thinking of doing the same thing...and perhaps add a wastegate so that I don't over do the boost...Thinking I could get my boost back up to 38-40 PSI...plus spool it up faster...Maybe you or someone could chime in and let me know if I would actually feel a difference with 8-10 psi..I have been reading a little on turbo function/selection...and how to determine what the best set up is....its not as easy as one would think...actually a pretty deep topic. I just figure if Cummins ran it up to 38-40, I can safely do the same. Thanks!!

[loranimal]

Originally Posted by 08Navigator

Extremely pleased with the way my ISX runs now, runs cooler..180-185 water temp range. The power is incredible!!. Its like I now own a high performance coach.

Glad to hear everything came out great.


So now that you're done do you have a quick list of what all you replaced/modified/removed during the process.


If you had to do it again, do you think the added effort to drop the engine would be worth it vice having to work through the hatch?


Any tips for the next person to watch out for?



Does Cummins have a rebuild(?) manual for this engine?


Thanks


Carl