Piston does not look right

Howling

Howling

Soot Sniffer
Joined
Apr 30, 2006
Messages
4,304
While my head is off I got a good look at the pistons and cylinder walls.All of them look absolutely flawless except for #2.I noticed on the outer edge were it is normally smooth it had some rough spots on it in two areas.I took some pics with my phone,looking for some answers on what could of caused this.





 
hows the ring end gaps and the bores? Might last forever might not last a day. all depends. need some measurements!
 
What programming are you running, pressure? injector size, nitrous, turbo, more info could help more. looks like the spray patturn on #2 is getting a bit further out of the bowl than the rest are, maybe from debris, or too high of rail psi?
 
Smarty tntr 7 lowest timing possible
Have a mp8 but it is only at 25%
dual cp3
75% EH
Had a 71mm charger

No nitrous
 
Howling said:
Smarty tntr 7 lowest timing possible
Have a mp8 but it is only at 25%
dual cp3
75% EH
Had a 71mm charger

No nitrous
Click to expand...

Well everything looks ok, i would like to know what you have for filter system micron wise, and how often you change it?

one other thing is that even with the mp8 on 25% it will fuel WAY beyond what is safe and it will do some damage when combined with the smarty, dont know why but we have seen this a few times. it's not so much that the overall psi is high but that it raises it at a very fast rate also.

Dockboy had some data logs on this very same point a while back.
 
3 Micron on Fass in the process of adding an additional 2 micron filter and going to a larger micron on the fass.

Truck rarely gets driven just turned 20k, filter is changed often.
 
What did the valves look like on that cylinder?
 
I'm pretty sure they looked fine.I will double check when I get back to the shop tomorrow evening.
 
Howling said:
3 Micron on Fass in the process of adding an additional 2 micron filter and going to a larger micron on the fass.

Truck rarely gets driven just turned 20k, filter is changed often.
Click to expand...

well, i guess that takes the debris thought out of the equation....

i would have to say that too much rail psi is the culprit, on the 04.5 and up 5.9's the added rp makes the cylinder temps alot higher, and with the allready small bowl edge too much heat will melt them.

turn the mp8 down or take it off you will be fine.

almost all of the most recent failures have something in common, high rail psi!
hope this helps
 
Yup looks like shes starting to melt. You caught it at a good time. It could and probably will get alot worse.
 
I've never really seen a melted piston look like this before.

So now I wonder if I should just put one new piston in without pulling the motor.Or is that to much a pain in the ass.
 
That fukker was about one good pass from melting out of the cylinder....you're lucky you caught it when you did.
 
Yup melted piston! Drop me a PM I have one available used but cheap! Disconnect the motor mounts take out the cross bar back of pan area, jack up the engine really high! Drop the pan pop the piston out put a new one in and throw the MP-8 away! Or at least put it on 0% Don't ask how I know this:nail:
!
 
Drop the pan and change the piston. Its not that bad I did it on a 6.7L a couple of months ago.
 
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