Flattened Lifter Roller - Now What?

[Plattman]

I have a 2001 3500 Express 15 passenger van with the 6.5TD engine. 256K miles on the engine. Found it a year ago on ebay in Mississippi. Previously it was ran by a state rehab dept. From what I understand, the vehicle has been properly mantained throughout its life (oil change every 4k).

Anyway, earlier this year I began hearing a tick, most easily heard at idle. Over time it has not grown worse. Recently I've been having OES DTCs thrown, and knowing that it has the original pump, decided it was high time to repace the IP. While I was in that far, it seemed like a good idea to pull the valve cover off on the side which the ticking was coming from.

With the cover removed, the first thing I saw was the the plastic retainer button for cylinder #7 exhaust rocker had come off and the same rocker was shiny (as opposed to all the others which were nice oil black). I have to assume that oil was not being pumped up the rod.

Next I pulled the hydraulic lifter and the picture shows what I found.

http://www.thedieselpageforums.com/photopost/data/2/medium/lifter_002.jpg

My heart went weak. I really want to run this van for another 100K.

Additional information:
The end of the exhaust valve shows some signs of being hammered, although it is not mushroomed. The rocker has slightly more wear at the point it contacts the valve stem.

My question:
In experiences out there or judgements that would say that I may be okay with just repacing the lifter? I don't know the condition of the cam lobe. I assume that the cam lobe is harder than the roller, but not sure. The roller obviously took some wear.

Also, what causes a roller not to turn? Is it a seconary failure to a stuck lifter or was it the primary failure? I'm guessing that the reason oil was not getting pushed up was due to the lifter dropping too low?

There was not much for previous posts out there concerning this condition.

Thanks,
Chad

[john8662]

Cool picture, nice to see the real cause of a noise.

So, the roller on the lifter doesn't turn? That was my very first question when i saw your picture. Is the roller wheel seized?

If so, that's enough to cause your wear, the lifter got to act like a solid not a roller.

You've found a needle in a haystack failure, very very oddball. Most lifter failures involve the plunger inside the lifter being collapsed, not the roller.

If your roller wheel is indeed stuck, replace the lifter and hope for the best. I know that the camshaft is hardened, but I'm not sure to what degree in comparison to the roller lifter's wheel. The cam lobe is probably harder.

The oil should really be changed every 3k miles, not 4k.

During re-assembly, check everything carefully. On the rocker arm check both the tip and the socket for the pushrod. The pushrod also needs to be inspected, check both balls for galling or wear. You'll also take care to install the pushrod in the correct orientation, the top ball is harder than the lower ball (has a slight copper color up top), and or a paint mark towards one end (designates up). You can also check to make sure it's straight. Rolling on a sheet of glass is a good test for this.

[JohnC]

Check the lift on the cam lobe. Can you see the lobe? Is it scored? Is the lifter scored? worst case is you have to pull the cam out...

IIRC, newer Diesel oils are specially formulated to address roller lifter failures. Maybe this engine was serviced with the wrong oil...

Good catch!

[Plattman]

I've learned more in the last 24 hours. Photos tell a lot of the story.

The needle bearing/pin did not wear well at all.
http://www.thedieselpageforums.com/photopost/data/2/medium/lifter_019.jpg
The groove grew deep enought that the roller was rubbing the inside (see photo) and dragging to the point of stopping. This wear coupled with the flat off the roller grew large enough that the hydraulic lifter could not compensate the gap and began ticking. Once there is a gap, the oil can not travel up the push rod because every time the gap opens up it drains back down. Thus the lack of oil on the inside of this rocker.
http://www.thedieselpageforums.com/photopost/data/2/medium/lifter_018.jpg
Not a great photo, but the needles are gulled and even tappered near the ends.

http://www.thedieselpageforums.com/photopost/data/2/medium/lifter_016.jpg

The worst part is the other three lifters in this corner of the bank have similar wear with small flats. I have to conclude the entire engine has worn lifter rollers. I would love to know why.

The cam shows streaks of gulling, but no grooves.

For those of your that have tore down high milage engines (>250K), do the original lifters show any wear in the rollers? I'm curious what typical is. These rollers have around .030" of bearing play (up and down).

The engine has ran good since I've owned it over the past year- No smoke, around 18mpg (orig 3.73 rear end), sufficient power for me.

My plan is to replace the lifters and button it back up and hope for the best.

Chad

[john8662]

Thanks for sharing this great information and photography!

I've always taken used lifters and checked for any slack by hand in the roller and haven't found any that have had any play. It's possible that the wrong oil could have contributed to the wear. Something we'll have to start looking for.

So, are you planning on replacing all 16 lifters, or just the ones you've removed on the corner?

It's a long process in chassis with the cylinder heads on, can be done though, but not so sure in the van though (done it in a truck).

[JohnC]

When the roller lifters were introduced the oil formulation was updated to accommodate the needle bearing's lube requirements. Prior to the update needle bearing failures were common. I don't remember exactly what the spec was, something like CG-4, but I'm gonna guess this engine was serviced with oil that was not rated for the 6.2/6.5. Some oils for gas engines carry a Diesel rating but probably not the latest. Worst case, it was serviced with an oil that was not Diesel rated at all.

[SmithvilleD]

Here's a link to the abstract of a 1992 SAE paper entitled:

Relationships Among Oil Composition Combustion-Generated Soot, and Diesel Engine Valve Train Wear

http://www.sae.org/technical/papers/922199

Basically ties roller lifter wear w/ soot levels in the oil & the oil's soot dispersant addititives.

[DmaxMaverick]

I would NOT recommend replacing the lifters and calling it good. At the very least, the cam should be polished, if it hasn't been worn beyond spec. As well, you should get a good look at the rest of the bearings in the engine.

Still, you have two things to consider with this. Cause and effect. It appears to me, with the info you provided, the lifters are the effect, and not the cause. If it were only one, then perhaps. Since you have several at the same end of the cam, I'd suspect a restriction, blockage or severe contamination of the oil.

If the engine had been serviced with the wrong grade of oil, the lifter would probably be the last to fail. And certainly no only a few. Roller lifters are not unique to GM Diesels. Many high performance gassers have them in use, and they don't require "C" rated oil.

I have seen many worn out lifters and flattened cams, but never flattened lifter rollers when there wasn't another cause, usually obvious.

Something caused this to happen. If you don't identify and remedy the cause, you will see a repeat of the effect.

[JohnC]

It's not the lifters, it's the roller followers. The needle bearings combined with soot in the oil is a Diesel specific problem. The CG-4 oil spec was specifically to address this problem.

The fact that is was a fleet vehicle makes me very suspicious about the oil it was serviced with.

[SmithvilleD]

x2

Hard to imagine the roller hammering/dragging along the cam lobe long enough to wear in that shape w/o impacting the cam lobe negatively.

[DmaxMaverick]

It's not the lifters, it's the roller followers. The needle bearings combined with soot in the oil is a Diesel specific problem. The CG-4 oil spec was specifically to address this problem.

The fact that is was a fleet vehicle makes me very suspicious about the oil it was serviced with.

I don't disagree. However, if it were the grade of oil, the problem wouldn't be 2 or 3 lifters. It doesn't add up. Perhaps a contributing factor, but not the cause. Some other gremlin was at work.

I know of at least a dozen early/mid 6.2's that were run for many years and 100K+ miles on straight 30 weight (not C rated, at all, and the cheapest stuff you could get), and no lifter roller issues. I can't explain it, but that old citrus farmer had a fleet of GM Diesels, and hardly ever an engine problem. He had a "oil is oil, just pour it in there" attitude, and it worked for him. None of the trucks were babied in any way, driven every day, and ran just about 24/7. If soot were the issue, it would have been staring him square in the face. Or he was just really lucky.

[SmithvilleD]

The pictures of the roller axle on this link (specific to the GM roller follower wear test) do look very similar.

http://www.swri.org/4ORG/d08/DieslTst/rollfoll/default.htm

http://www.swri.org/4ORG/d08/DieslTst/rolfolow.pdf

[arveetek]

I don't disagree. However, if it were the grade of oil, the problem wouldn't be 2 or 3 lifters. It doesn't add up. Perhaps a contributing factor, but not the cause.

Actually, from what I've read, he doesn't say there are only 2 or 3 lifters worn. I don't think he's had a chance to pull them all yet. In fact, he does say he assumes he has worn lifters throughout the engine. One just happens to be worse.

I'm with JohnC on this one...I bet it's had the wrong oil in the past. As has been stated, the "C" rated oils were rated specifically for the GM diesel roller lifter engines, since they were so easily damaged by the sooty oil. From what I've read over the years, the roller lifters are the weak link when using wrong oil, not the mains or rods.

Just my humble $.02.

Casey

[Plattman]

I have pulled all 16 lifters (heads still in place) and everyone has excessive roller pin wear. Some have small flats in the roller, some don't. None wore to the extent as the one pictured. The #7 exhaust lifter happened to wear faster than the others.

From the information reported, it seems to be oil related. From the limited information I have about it's previous life, they had the oil changed at a "speed lube" center. Following my own curiousity I will call the business listed on the windshield "Next Oil Change" sticker that was left in the vehicle.

All other wear surfaces that I can see from the top of the engine appear fine (Rocker arms and push rods).

I also will try to evaluate the cam's condition by dropping a lifter and push rod back in and use a dial indicator to measure the lobe height.

This vehicle is our family van as we have 7 children.(It's a diesel lover's dream to find a diesel powered family vehicle! These diesel Express passenger vans are somewhat rare-I've been driving diesels for my work car since 1988, starting with the GM 5.7L) All this to say I'm running out of time having a vehicle down and pulling the cam shaft is more than what I'm ready to get into now. The current plan is to drop a set of good condition used lifters in (they were dirt cheap on ebay) and put everything back together this weekend. I will monitor wear using oil analysis.

Thanks for the discussion so far. Soon I will get to experience replacing lifters with the heads in place on van (cylinders #1 & #2 are completely inside the body). Is there a knowledge base of proper technique for doing so?

Chad

[SmithvilleD]

Understand the budget plan. I gather you've had the van for a year & know the oil/oil change maintenance you've done in that year. How many oil changes did you do?

My reason for asking isn't to question your maintenance schedule, but thinking along the lines of suspending/diluting/removing was appears to have been high soot levels.

If you've only done 1 or 2 oil changes, maybe there would be some benefit from a couple short interval oil/filter changes with an oil that has good soot dispersent levels. Don't know how effective this strategy would be, but a couple quick rounds of dino oil/filter changes is relatively cheap. (each done on a warm engine at operating temps in hopes of having as much stuff suspended in the oil as possible)

[Plattman]

I've been running sythetic and have only changed the oil twice in the past year. It does seem like a good idea to do some quick changes to try to clean out some soot. I've read a post about running the engine on ATF for 5 minutes and then changing oil and filter. I'm sure there are a variaty of opinions on this. I guess ATF must have good detergent properties?

I for sure plan to change the oil very soon as I know I've introduced some dirt just by having the valve covers off.

BTW, I did get all the lifters installed. Went better than I had expected. I made a insertion tool that worked quite well.http://www.thedieselpageforums.com/photopost/data/500/medium/lifter_tool_004.jpg

[john8662]

Nice tool.

I wouldn't run straight ATF. Just fill the engine with the correct oil and run it for around 500 miles or so. Then drain off 1qt and fill back up with 1qt of Diesel fuel. Run the engine for 10 minutes at idle, then drain, replace the filter and and fill with fresh oil.

[NH2112]

A quart of Marvel Mystery Oil works great, too. I think what I'd do in your case is install the used lifters and continue to run the engine, and in the meantime work on putting another engine together or finding a known good running engine to swap in when (not if) you see more problems.