Jack,

In your video with only the starter turning the motor - Do you think that the rotation of the motor slows with / coincides with the thump? To me that would indicate a bent intake push rod.

 

Thanks. I do have the Ford service manual and the 6.0 is different in procedure. If it's pushrod, the engine HAS to come out. I have the tool to remove the rockers and pushrods without disturbing the head bolts.

Randy, not sure what pushrods were installed in this Ford rebuild. It could have been the 6.4 lengths.

I'm still trying to theorize why it thumped, and then didn't. And why I hear ticking, unless that's me just hyper looking for a non-existing problem. But with a career of listening for subtle brake noises, I'm not sure that I'm not noticing. I should probably post some of the other vids I have, although sound recording isn't at it's best with an iPhone mic.

It's never thumped before, but I have to look at all my wire tests that I was retaking that the iCloud ate to get a better handle on sitting time.



I'm starting to go down the path that they may be a lifter issue, in that it does not retain hydraulic pressure as well or has a hurt extension spring. Maybe the tapping I've always heard at hot temp is excessive pressure bleed off with thin oil. And maybe with a long delay in starting this truck the problem injector bled down. (On edit, jsm were thinking the same)

Or as I stated earlier maybe with the longer delay a valve had some hysteresis due to oxidation, and there was a slight bend in the pushrod. But the lifter pump-up took out the small bend clearance.

I'd rather not pull this motor and take it apart for one lifter, but I'm starting to look at what I need to gather to do so if need be.

Despite all the uncompensated IDS injector checks I did, which showed some injector issues, this ain't them.

 

Yeah, despite real fully charged batts and a faster spinning starter, you can hear the motor fighting against higher compression on one stroke.

During the last 18 months of utilizing video for issues I've learned it can be a really good augmenting tool. As in the first vid of this thread, I used it to record the inspection then replay on my large iMac monitor as these eyes are not what they used to be. While the video is jumpy while an old guy is standing on steering linkage and recording with shaky hands, I can keep hitting pause on the vid to get a still shot.

The other is noise. Sometimes taking a video then replaying it slower then normal you can hear things otherwise lost. Here is the first jumped cranking slowed at half speed and then all the way down. You can hear the fight better.

***** Edit - Time out, I'm redoing the vid.

The lower frequency thump noise is lost by slowing down however, or at least it doesn't sound the same.

 

A bent pushrod will thump all the time, a flat lifter will thump till it pumps up. If you can't find a bent pushrod, swap the oil for 15w40 and see what happens. I run Mobil 1300 15w40 year round down here.

I cured a leaking lifter with this stuff in an airplane. Home - Camguard I'm a skeptic when it comes to additives but this stuff works and they make it for diesels.

 

You might as well tear into the motor as I would assume that you'll be inspecting and replacing all like components, not just fixing the components on one cylinder.

 

If it's a slightly bent pushrod that the lifter is partially compensating for, I'll change the pushrod.

If it's a lifter that I can attribute to one of the front cylinders I'll pull that head and change the lifter.

It's it's one of the rear lifters where the motor has to come out, I'm still seeing this truck going away.

jsm, yeah I always have run 5w-40 syn, the last two changes being Delvac. I've thought about a straight weight before as I use it on the farm for the Jimmy two stroke.

 

The diagnosising by video video just finished loading from the earlier post.

 

Can sure hear that video. 15w-40 isn't curing that, sorry Jack. I agree with the course of action except the last one. Sell it to get out from under it or drive it until it drops?

 

Maybe some 75w-140 will take care of it!

I think that if there is a minor defect in the valving of a lifter you can avoid the issue with oil viscosity if your running a wide range like I am, or solve a debris issue with some augmentation. Yeah I don't think that is going to work here, but it was a good suggestion for some situations.

Trying to check valve lift right now to see if I can find my problem cylinder.

 

After this noise has been lifter isolated, I'd start pulling as many push rods as I could and replace as many as possible with the shorter rods. I don't think the OEM 6.0 Rods have the copper clad tip as noted on the updated 6.4 FORD rods, this way you can see if they've been updated already by noticing the copper end (which should be oriented up at the rocker, btw) .

Also, I noticed one of your pushrods favoring the edge of its chase, so when you pull it out Hopefully that's the one that giving you problems. As each get pulled, you might see its witness mark on the side of the rod where it's been rubbing on the edge of its corresponding chase. If you refer to 2:28-2:37 for an example, you can see what I am referring to in your opening video. At any rate, it would be good to know you can access the offensive rod with minimal effort.

I hope that's all it is...

 

BW,

This motor was rebuilt in 2008 so I believe they are all the shorter versions as they have the copper top. Thanks for looking that carefully at the video. I agree about that offset too.

-----------------
So today I manually turned over the crank 16 rotations to try to bleed out the lifters so I could do a dry check of valve lift. Without oil they won't achieve normal valve lift, but I was trying for a cylinder to cylinder comparison to see what was happening before pulling injectors and then rockers / pushrods. I didn't even try to get a perfect perpendicular stroke so it could be a few thousand off. And I think the early cylinder lifters were not fully evacuated.

Edit: Result if you don't want to watch the video

 

Well, at least you don't have to remove every push rod.
Another fine video Jack, your a movie star!

 

These vids I could do without in my collection!

They are not public though, only with my links.

 

You know Jack, Anthony's looking for someone at the moment


So what are you thinking ?

Unfortunately it looks and sounds to me like #8 lifter collapsed...

no wonder it was so loud in the cab.

 

The only engines I care to be working on under a regular basis would be 289 HiPos. I do have a '69 351W HiPo to fit into the mix, though.


Drum roll, please ......

The answer is ........ a perfectly straight pushrod. And perfectly good rocker.

So lifter or cam lobe. No particles in the oil filter, visually or magnetic. And didn't shut down due to low oil pressure.

Two relative balance IDS tests prior to this showed no issues. Cold, #2 down 1% which I saw years prior. Hot all at 100%.