It's time for yet another Rob thread about some issue or another.
If you all recall, at the end of December, I revved my engine way up and things came loose.
I found my #8 rocker basically falling off, and it was making a 'chuffing' sound as the intake valve was opening late(I think).

Tightened it down, things /worked/ again. I started to notice a bit of a limp and slight chuffing at speed when loaded and the engine quieted down.
I found out that my #8 exhaust pushrod was seriously bent. I swapped it with a straight one from #3 and straightened that bent one as best I could. Engine quieted right down and had more power... for about 100 miles. Then it started doing the same thing.
Got a Melling pushrod from the local store and swapped out the bent #3 one(easier because no need to remove half the air box). I checked and found #8's pushrods were both in good condition.

Which leads me to today. The engine runs decently. It has a slight lope/limp I can't cure(especially lower in the revs), and I'm thinking I might have damaged my #8 lifters when the rockers came loose.

Part of the reason I think this is if I rev it up in the 3K range for a few seconds, and then back down to 1600 cruising speed, it feels smoother for a little while, and the faint chuffing I hear/feel seems to disappear/quiet down. I'm thinking the higher oil pressure and speed lets the lifter 'pump up' slightly and take up the slack better.

The lifters that are in it are brand new ones that came in the kit my shop bought, probably enginetech or the like.

So, at this point, I'm not sure what to do.
I have four options to try:
1. Try to shim the valve stem on #8, pushing the lifter down and giving it more travel(in case it's maxing out).
2. Replace the #8 lifters with new ones - what brand would be best?
3. Replace the #8 lifters with used ones - I have a couple of sets of good looking OEM ones I've pulled from two of these engines(but I don't know how to test if they are good).
4. Replace *all* the lifters with used OEM ones.

Thoughts?

 

I just asked more or less this same question and didn't get much input. Of course you know this because you replied to my thread...

https://www.ford-trucks.com/forums/1...e-lifters.html

I asked over on OBN as well, and didn't get an overwhelming response, but I did learn that some of the cheaper ones are not needle bearing rollers but bushed bearing rollers.

Valve lifter recommendations

If you had push rod bending going on it is reasonable to think some violence happened to the lifters. If the price is not obscene I would prefer new OEM, but I have not called Ford to see what they charge. Beyond that I would think it's a toss between re-using the stock ones or buying another set of (hopefully) good quality aftermarket ones.

Also, just FYI there was a guy on OBN who got a set of Enginetech push rods and the lengths were all over the place. I don't know what push rods you used but if you do the lifters, check your push rods while you're at it!

Enginetech Junk

 

If #8 intake valve was opening late, could it be bent? Have you checked the valve height? I would also measure the travel of the lifters and valves. Are the intakes and exhaust valves all opening about the same? You could perform an air test to see if the valves are seating. You could remove the spring on #8 and check to see if the valve is true or if it is freely moving within the guide. This would be a good time to replace stem seals.

Please keep us informed.

 

Makes sense.
Apparently, they use the same lifters in the 7.3 and 6.0 Powerstroke, IIRC. I've been hearing issued with QC on oem lifters these days once I started looking at those engines too.
This is why I'm not sure which would be better - a new, but potentially failure-prone lifter, or an old, worn, but also 'has lasted' lifter.

Hm, interesting. I'll check them with a set of calipers when I get a chance.
The new ones I put in seemed to match the (straight) one I pulled out, by calibrated eyeball.


So, just for reference - I've used the glow plug resistance trick to try to figure out which cylinder isn't working right. #8 has been consistently lower(=cooler temps) than any of the others. And I swapped glow plugs with #1 and got the exact same readings and differences.
Doesn't seem to be. Either of the #8 valves. They move up and down easily with a lever, with good pressure.
No, I haven't. I've assumed that it was machined correctly along with the others.
Haven't done that yet, do you have a specific procedure in mind, or just "put dial indicator with mag base on valve, crank over slowly"?
Eyeball says it seems to be, but I'd not see a .050 difference while cranking it over.
Did this. I didn't hear any leaks into the intake or exhaust with the valves closed, at 100 PSI air. Did hear slight hissing past the rings which is expected... but honestly a /lot/ less air was escaping than I expected.
Haven't done this, but did push it open with a lever, and everything /seems/ to be intact.

It's a newly rebuilt engine with less than 20K on it.
Stem seals look great.

 

Was it rebuilt or remanufactured? Checking the valve height will give you an indication of irregular wear or not and to some degree the condition of the seats, as compared to the other valves. Although this wont tell you if they are sealed or not. The top of the stem could be worn as well.
Checking valve/rocker arm travel with a dial indicator dial indicator would help pinpoint problems with cam lobes, lifters, and push rods.

Sometimes the rocker arm is pushing on the spring rather than the valve stem tip.

If your springs are worn and the valve stem is stiff it may not close properly.




Worn Cam Lobe





Worn Roller





Worn Seat

 

beware of parts made in mexico, lately ive seen a few pairs of enginetech's lifters that were pretty nasty.

 

Alright, so this weekend I unexpectedly had some time.

I got everything pulled and got my valley pan out cleanly, with no damage whatsoever. Being only 1 year old, nothing was stuck too hard or anything.
I did find out that this engine, being an 88, has coolant passages exposed to the under side of the pan gasket on the heads; apparently they plugged them in later model engines.

I pulled the offending lifters(decided to pull #3, #5 and #7 so I had some baselines) and couldn't find anything wrong with them. Rigged them up in my lathe to where I could push on it with a junk pushrod... and it bent before moving the plunger down any.
Cams looked good, rollers were smooth with no noticeable wear, The only wear I saw was a few thousandths on the side of the lifter where it rubs against the jagged oil gallery ports halfway down the lifter bore.
I've seen the exact same wear pattern(and depth) on the lifters I took out of the engine with XXX,000 miles on it, so I don't think it's a problem.

I grabbed 6 random lifters from my pile of old lifters, disassembled them, cleaned them with mineral spirits, reassembled with a little bit of engine oil and dropped them in the engine(dry, filled with air).

After reassembling the engine and getting it bled, it ran pretty smoothly. Got the timing dialed in again, and took it for a spin.

It looks like it fixed the problem. Much smoother under load, very little vibration in the 1600-2800 range and the noises are consistent.

So... I guess the lifters were a problem, somehow.

 

Did you by chance disassemble the ones you took out to see if you could identify the problem? Kind of seems like the clean/inspect method might not be a very good way verify lifter health.

 

I have the ones I took out, but I'm not sure what I'd be looking for exactly.
The ones I put in I verified that the spring/ball check valve held liquid above it when at rest, and let liquid flow when I pressed it with a screwdriver. Other than that, I'm not sure what could go wrong. There isn't a whole lot to these things.

Oh, I did verify that the pushrod length was correct(or close enough); at 'rest', the pushrod was pushing down into the lifter about .06-.09 by calibrated eyeball. So that means the pushrods aren't bottoming out or pushing the limits of the lifters.

 

do the gp resistance test again

 

I did it yesterday, and they were a lot better. I think #3 was 1 ohm /higher/ than the rest(Though I didn't check #6,8 as they are under my air cleaner), but all the others were really close.

Unfortunately, my tester really isn't accurate enough to determine anything closer than that(it keeps varying within a 1-ohm or so range), but it said enough.

Sound and vibration seems to match this -- it's not /perfect/, but there's a lot less shaking/knocking from things. It smooths out quite well under heavy acceleration, so /most/ of it is probably injector variation(I still have a 'prototype' set of Stage-1 injectors in mine, and the spray patterns are all over the place).