Since there have been a couple recent threads on valve lifters and several discussions on the IDI valve train in general, I decided I should stop being lazy and open up a lifter. I am curious about what could break, stick, clog, or otherwise go wrong inside the lifter and cause it to fail or function inadequately. I don't pretend to have any of those answers yet, but I figured a good place to start would be to educate myself about what's inside of a lifter and how a properly working one is supposed to look. If anyone has a known "bad" lifter I encourage you to take it apart and document any physical damage you find and add it to this thread along with the engine symptom it created. Here are my pictures of a disassembled OEM valve lifter out of a 1994 NA 7.3L. Note I did not disassemble the roller since the shaft appears to be pressed in place and its function is completely separate.

 

Interesting. I wish I had seen this, I just scrapped my old lifters, there were at least seven that were bad, some didn't pump up but one was locked solid at the top. Thanks to that thing I tore down the top end on my engine on suspicion of a blown head gasket.

 

Is that a rubber seal on the top of the spring-keeper above the large spring? Or just a reflection from the contour. Looks like a seal should be there.

 

No, that is just a reflection. The spring keeper holds the small spring inside of its cup, and the little ball seats against the hole on the bottom of the inner body like a check valve. There are no seals or soft parts at all.

 

Nice post, always wanted to see inside. Never went to the trouble to break one a part.

 

wow ! this is great F834

this is one subject i have much been interested in ..

but had yet to see the internals of what one of these lifters actually looks like .. and what could lead them to malfunction ..

hope somebody has some known bad ones to compare against ..

good to see they are all hard parts

gonna save a link to this thread .. hope to see more .. good stuff

thanks for posting this ..

 

The 6.9 that came out of my truck has a bad one ~somewhere. When I tear it down I will see if I can figure out which one it is. That won't be for a while yet, as I have nowhere to store it except outside under a tarp and I don't want to open it until I need the parts for my 7.3 build.

Edit: glad there is some interest in this, I know it's a mundane detail but the valve train is proving to be an issue with high rpm and high boost. I hate not knowing how something works.

 

My problem is that I haven't been able to find one obviously bad yet.
I have had a cylender that was thumping a little, seemed like the lifter was compressing more than it should. Pulled the lifters and replaced, along with a good cylender as a 'control'., problem went away.
I can't see *any* difference between the 'control' lifters and the 'not quite right' one.

I haven't found a totally collapsed lifter yet, one that wouldn't pump up at all. And any lifter I pull apart and clean seems to work just fine.

 

That's one thing I was wondering about... if the problem was the result of oil sludge then there would not be anything to see once you disassembled it and cleaned it. I guess that would be a good problem to have, but it would be a lot of wasted work to reinstall them only to find out you still had a problem that you could not see by looking at it.

 

If someone could post the manufacturing specifications for the hydraulic lifters you could then measure the parts of your lifters and compare them to the specs to see if they are worn out or damaged in a way that is not obvious to the naked eye.
Also you would not have to wait for a damaged lifter for comparison.

Here is a link for a good basic explanation of how hydraulic lifters work.
Hydraulic Camshafts and Lifters 101 - Engine Builder Magazine

 

yea pullin' good stuff and bad stuff then measuring usually works ..

i found an idi one time i think an 86 at the bone yard ..

had been stripped of all the easy topside goodies

starter .. injectors ...
pump .. glow plugs ..

thing is they didn't think to take off the valve covers because it should have had the old style rockers .. well .. i knew this also .. but said .. what the **** .. i'm already here .. it'll just take a few minutes to see .. most of the stuff was already moved outa the way anyways by now

low and behold when i got off the covers .. it turns out there is a brand new 'looking' full set of updated rockers .. probably a recent new upgrade before the truck was wrecked .. and all new nice oem pushrods .. they looked new and looked just like mine not knock offs

anyway measured the total length and they were a 3/64 on averager longer and had nice round tips .. my old rockers were very scored and this was a bad design .. glad the new ones fit right on there ..

anyways .. just keeping this thread alive .. hopefully someone has some bad and good injectors they can put a vernier caliper onto and compare sizes and maybe build some type of spring pressure tester for a given length and put it up to a digi scale for the spring ..

i will probably pull these along with several other parts when i find them from the boneyards .. but with no way of knowing if they ticked or pumped up properly i cannot know a lead if they are good at all or bad ..

i think it's a nice goal to develop a brain bank on what makes a good lifter and a bad one .. so can match internal parts to sets from good parts that work well and ensure smooth long operation

 

I'm going to give this thread a bump because I found this video that seems to have some useful information:

They are advertizing american-made lifters, which turn out to be made by Eaton. They are "for" the 7.3 PSD, but as far as I know, 7.3 IDI lifters are the exact same.

I'm thinking these look better than any IDI lifter I've seen, due to the longer contact patch(which is where I see wear on /any/ lifter I've ever removed from an IDI), but I'm not sure if it makes any difference in practice.

 

Those should work in our engines, the sealed power and engine tech part numbers listed on RockAuto are the same for both IDI and PSD 7.3's. The performance lifter looks great but wow they are a bit pricey. Their regular lifter is on par with other aftermarket replacements though. If I end up buying new ones I would strongly consider these.

 

How much more was it for the high performance?

 

The video says the standard ones are $179.99 for a set of 16, while the high performance lifters are $379.99 for a set.