Dont ask how many idle hours he has.

 

That's an interesting idea about the camshaft machining. If all or some of the lobes were ground with taper on them this could certainly cause a problem. It would have to be pretty bad to cause problems because there is some clearance in the lifter bores. Or if the block was machined with a lot of lean to the lifter bores with them out of perpendicular. A lifter bore out of plane would cause the pressure angle on the lifter to be higher but wouldn't give it a tendency to want to rotate.

When I grind a roller cam I grind it without taper. When I grind a flat tappet cam I purposely put taper into the lobe. Usually this is about .0025 total taper from one side of the lobe to the other. That's .0012 on both sides(not a lot).

From what I've read it almost seems like there are multiple problems. Problems with the lifters, lifter guides and problems with the camshaft itself where it wants to chunk out at fairly low miles in some cases. Last week I reground a cam out of a 7.3 Powerstroke diesel for a customer. It had several lobes that were just starting to do that pitting up near the nose. It took about .005 of grinding to remove that and make the cam as good as new. What's interesting about it was how lobes that didn't have the pitting still needed to have almost as much material taken off to get them to clean up. Where the rollers had been running looked smooth but the surface was actually worn a bit. I think it had run about 500,000 miles or some crazy high number. He was rebuilding it for one of his customers.

I wonder if what happens is the surface is hard but then over time gets work hardened a bit too hard which cause it to become too brittle. Over time then it fatigues and starts to flake away instead of flexing a bit under the load.

 

It would be nice if the people who report failures actually go into detail about the trucks use history up until that point so we can all see if their is a conclusion according to type of use.

Scraprat has his own thread that he updates and gives enough detail about his use. He's had a good run so far with his and we thank him for sharing as much as he does. OBS460 posts enough of his use pulling a decent sized and weight fifth wheel. Not sure of his mileage and ratio of loaded vs unloaded use but at least he's reporting in. What noone so far has reported on this site is actual parts in hand from a failed engine so we can actually see pictures. I had an engine go down in one of my trucks around the 30k mark. It was taken care of under warranty and they didnt even investigate past low compression in cylinders #7 and #8. Threw a new long block at it and gave me the truck back. That engine was in an F600 dump running around @ 20k. Replaced engine is closing in on 60k now without issue so far.

 

There have been people with failures that report with proof or first hand knowledge being their own vehicle. I will give zero weight to any internet post or comment about what someone read about some "Ford mechanic" giving their opinion of unverifiable info. I've heard so many excuses for the cause and the reasons for the failure they are almost as plentiful as the documented failures themselves. "Oil injection ports" not machined well enough. Poor metalurgy of cams or lifters. Plastic lifter guides. Variable displacement oil pump doesn't pump enough oil pressure at idle. Ford is just junk. On and on and on with no evidence just speculation.

The amount of people who have posted proof would fall into the rare category not the common failure like all the comments and speculation make it out to be. This sub-forum for 7.3 engines sometimes goes days without a single post and it goes weeks and months without mention of a personal failure. That doesn't seem very common when there are hundreds of thousands of 7.3s on the road.

 

I never said it doesnt happen. I said it doesnt happen as often as all the internet hype makes it out to be.

 

I must of got the special parts that you're peeing your pants about. Oh that's right highway miles differ from ghetto miles.

 

No one said it did except the voice in your mind.

 

Do you own a 7.3 or a 6.7 equipped truck?

 

My 2022 Georgetown GT7 36K7 on an F-53 Chassis has a 7.3l engine with 17,350 mi, on Monday driving Home the check engine light started flashing then a loud knocking noise.
just got it Towed to Ford

 

That doesn't sound good. That sounds more like a rod bearing or piston.

 

Here the double knock, that sounds like a broken piston to me. They will probably won't even tear it down just replace the motor.

Denny

 

Learned in high school if you were a Motörhead, knock in the engine is usually a rod bearing or wrist pin. The Ford dealer was “clueless “ per the OP? Something about the odor of a fish comes to mind!

 

Doesn't sound like a lifter. Sounds like uncle rodney has come knockin'