I hope it isn't too bad once you get the head pulled... good luck.

 

I got it pulled a little while ago. it dropped one of the exhasut seats on #4 just like I thoguht. It had been making contact with the piston. I will get some pics up in a while. Now I need to find somewhere to get this fixed.

 

How does the piston look? How loud was the knock?

 

Knock was no louder than a loud injector, but just didn't sound right to me. it got louder higher in the rpms.
Here are some pics.
http://www.putfile.com/pic.php?img=5861576
http://www.putfile.com/pic.php?img=5861574

 

Oh and fyi #4 is washed clean because I pulled the pushrods for both valves before I moved it to its final teardown spot. Diesel does a good job cleaning them up. However I could have done without the oil it sucked on top of the piston from the crankcase. Overall everthing looks good. Crosshatch is visible on all the cylinders there are no signs of excessive heat or fueling, if that durn valveseat had stayed in place . Oh well now I know for sure and I'm glad I did not run it anymore.

 

Doesn't look too bad... considering some of the carnage we've seen lately...

 

Tell me, how does this happen?

 

Most say it's the excessive heating that occurs when high egts have been run too long or too often. This combined with rapid cooling when the fuel is cut is like a big heating and cooling cycle that occurs everytime you get the egts up there then let off. I was waiting for this to happen but, it could have waited until after hunting season. I drew some good tags and I've got a lot scouting to do. OH well I've got my vitara to run around in.

 

Ok for the cause but how about the fix? Replace the seat and regrind the valve? Stake all the seats somehow? If this can be a problem surely the high performance engines have found a solution and if so what ?????

It looks like the psiton is OK and I didn't see any dents or other damage unless the photo didn't show it but will you need to change it or not enough damage to warrant changing it?

 

The valve left an imprint but i am going to smooth it out and run it.

 

I wouldnt be scared of what I see on that piston at all. I have run way worse with no problems. I wouldnt go crazy when you smooth it out though . just take off the high spots and leave it at that.

 

after reading this thread im starting to get worried. i also have a tapping/slight knocking noise and cant figure out where its coming from. it started after being rearended while i was towing a trailer. it is louder from the drivers side and i do have alot of oil on the breather tube w/ a little smoke coming out at idle. what do these signs mean, hole in the piston or broken ring lands? btw i only have 11,500 miles on the truck. i have driven over 1,000 miles since the noise started and the truck isnt running rough that i can tell anyway.

 

I decided what I am going to do to fix it. I am buying a new bare head from cummins, one new exhaust valve, upper gasket set and I should be good to go for around $1500. However I don't think I will keep this truck because I can't help using the power. I may go for a new gasser since it's a little harder to modify them.

 

When the going gets tough... Don't give up now...

 

I may buy a gasser for a primary truck, but I still love the sound of an ol 12 valve and I may have to find one for a bombing truck. Actually I should say If I buy a gasser I will have a 12 valve for modding purposes.