Camshaft failure Cummins isx15

[RichHomie27]

(08-01-2023 )Rawze Wrote:  Maybe find out why are the rockers got chewed up?..

If they have more than a million+ on them ok.. but otherwise... something caused it.

#1 cause = Neglect of the crank case filter.. and allowing crank case fumes to build up in the engine and starving the top end.

#2 cause = some fool not doing oil changes based on fuel mileage and going too long between changes. Oil changes should be based on this chart...
http://rawze.com/forums/showthread.php?t...9#pid76569

#3 cause.. some fool using synthetic oil in the engine .. and then not doing oil changes but every 28- 30k mile or more intervals.. or relying like an idiot on oil sampling and bypass filters garbage that these engine killing XM radio shows try to tell people to do.

#4 cause .. excessive blo-by and the crank case circuit cannot keep up with the fumes building up any more... allowing pressure to build inside engine, starving the top end of oil.

#5 ... no one ever adjusting the overhead valves every 2 years or 250k miles like they should... and the rockers are riding the cams all the time.


take your pick.

I had to replace camshaft due to ticking noise back in February, when mechanic did this he replaced the camshaft and only ONE rocker. 3 months later I come back due to a knocking/clunking noise and it ended up being 2 more rockers, so he replaced those 2. Now once again I’m back bc same knocking/ ticking noise. So new mechanic says it’s due to not replacing the 12 rockers at once the first time I got new camshaft. I take care of my truck pretty good I would say, since the short time having it. I don’t do oil changes to to often bc I haul sand. So it takes me awhile to even just put 10-15k miles on my truck, but maybe I should stop going by miles and maybe go by engine hours bc my APU has been out for awhile so I do IDLE. I try to do oil change on average every 15k I would say but it can take me time especially if work is slow to even hit that 15k+!
Oh and last time I got the 2 rockers replaced, old mechanic I was dealing with did use a Mystik Synthetic Blend oil when I did PM. Before I always tried to use Mobil Delvac.

I do have minor blow by. At 693k miles now. Besides this issue engines runs really strong, never lose oil pressure. And blow by hasn’t gotten any worse the last 60k miles.