Originally Posted By: OVERKILL
Originally Posted By: Quattro Pete
Originally Posted By: OVERKILL
Now, all that said:
*IF* and that's a big if, the 6.4L cams are steel, then that changes things entirely. I say that because, presently, based on the information I have, the issue doesn't appear to happen on them, despite using the same lifters. This leaves the key difference as being the oil. If the cam core material is different, that blows that theory out of water, as we have another variable in play.
If it's the oil, then why aren't cam and lifters on ALL cylinders affected, instead of just some of them?
It is generally just one lifter that seems to lock up and catch the dead. It would be unusual for multiple lifters to fail at the same time. My observation is that, whatever seems to be the failure mechanism with these lifters, something with the heavier oil seems to mitigate it
why that is, that's the unknown. Also, it is not always the MDS lifters that seize up, it can happen with any of the 16.
It is not an incredibly common problem, but it is known to my dealer, they've done cam and lifters in a few 5.7L's.
Quality spills do happen. When I was working at Eaton about 6-7 years ago, they had to stop production on the lifter line because bearing needles were coming in with lines on them from the supplier. The edges of those lines would break down and put debris into the bearing, which would eventually cause the roller to lock up.