Dropped valve seat, the 3rd Gen KDP?

[gitchesum]

Seems like it to me.



For those that never had a 12V, there used to be a little dowel alignment pin that would fall out of the hole that was machined too big. When it did, it usually dropped in in the gear train, and most of the time resulted in a big crack in the timing cover which resulted in a huge oil leak. The repair involved removing the cam.



Now it seems we have the same situation. Something must have been machined just a little bigger than it should have and now the valve seats are dropping out, usually resulting in a busted motor.



I was one of the lucky ones. Mine dropped, but it never got busted up. It left it's little mark on the piston, but all I had to do it have a new seat installed and put the head back on.



Funny thing it, Cummins is/will say the same thing they did about the KDP. The failure rate is so low, they won't even acknowledge the problem, much less offer any assistance with the repair.

 

[champspa]

yes , it doesn't matter to them and if it had happened to one of their warranted engines they would fix it . our engines a warranted by Chrysler and 100k is it. I have never had a kdp problem the were always tight when I took the cover off to inspect . I've had other issues not big, like fuel lines and that was it until the crank broke at 257k , I'm on the second motor now

 

[SShafranko]

How did you know you dropped a seat? Was there noise?

 

[gitchesum]

Big time noise. Sounds like a rod knocking. Also a noticeable miss in the engine.

 

[rbattelle]

I'm not aware of a dropped valve seat on a stock truck operating at normal EGT. Has it happened?

Ryan

 

[DonFitzwater]

I've seen it on a couple of marine 24 valve engines. I'm not familiar with any in trucks that were stock though. It seems to be caused by high egts and rapid egt increase. The old man always said that stock was good... ... ... ... I never did listen!:-laf

 

[Tinman]

Aren't the later CRs improved in regards to this issue?

 

[steved]

Aren't the later CRs improved in regards to this issue?

They changed valve tolerances, which I believe was thought to retain heat in some fashion... preventing it from reaching the seat??

 

[Gary - K7GLD]

They changed valve tolerances, which I believe was thought to retain heat in some fashion... preventing it from reaching the seat??

Actually, I think the standard is for maximum heat transfer from the valve seat to the head - to provide best lifespan and operation of both the valve and seat.



Back when I worked at an engine machine shop (a million years ago! :-laf), we commonly installed drop-in seats into Ford flathead engine blocks - the trick then was to slightly recess the hardened seat into the block to allow the block area surrounding the seat to be "peened" over the outer rim of the seat, providing a lip to extend over the edge of the seat to help retain it in place. The peening also enhanced the "grip" of the block-to-seat union.



We also applied some sort of white paste to the machined seat pocket prior to installing the seat to flow between the 2 surfaces and enhance sealing and heat transfer - but it's been so long, I forget what the stuff was. Then, of course, the block area around the seat area was heated for expansion, the drop-in seat was exposed to a blast of liquid Propane to freeze it and create contraction - and it was dropped into place.



These were usually track racer engines - never heard of any of them dropping a seat...

 

[roadking]

Seems like it to me.



For those that never had a 12V, there used to be a little dowel alignment pin that would fall out of the hole that was machined too big. When it did, it usually dropped in in the gear train, and most of the time resulted in a big crack in the timing cover which resulted in a huge oil leak. The repair involved removing the cam.



Now it seems we have the same situation. Something must have been machined just a little bigger than it should have and now the valve seats are dropping out, usually resulting in a busted motor.



I was one of the lucky ones. Mine dropped, but it never got busted up. It left it's little mark on the piston, but all I had to do it have a new seat installed and put the head back on.



Funny thing it, Cummins is/will say the same thing they did about the KDP. The failure rate is so low, they won't even acknowledge the problem, much less offer any assistance with the repair.

I feel your pain

 

[Rattler]

I went today and looked at an 05 with a dropped seat on # 1 cylinder. We were looking at the head talking over what to do when i noticed the head is cracked between two of the seats. :{:{ He is going to look into a reman head tomorrow. Randy

 

[Shadrach]

I talked to someone recently who had this happen on his 04. 5. After asking lots of questions it turns out that yes he had added lots of extra ponies and when I asked about EGTs he did actually have a pyro and he said that he had hit 1600*F pre turbo Case closed. Shadrach

 

[Rattler]

The truck i was referring to is a work truck. I don't think he has any upgrades on it though. The truck was making an in town delivery when it dropped the seat. Randy

 

[Wingate]

You got EXTREMELY lucky if it didnt trash the piston and turbo... Wish I had that kinda luck, i'd go buy a lottery ticket!

 

[Rattler]

On this head, you can see where the seat came out and then went back in its hole a little bit cocked. They were at slow speed and stopped when it happened. The valve made a couple of peck marks on the piston top but nothing too bad. I have not talked with him in a couple days, he was going to look at a re-man head because of the cracks.