Bad lifter vs bad injector ticking on 60x engines? - PeachParts Mercedes-Benz Forum

JHZR2 · #1 05-01-2022, 11:18 PM

What’s the best way to tell if a stethoscope is inconclusive?

Here is a video at hot idle:

https://youtu.be/JtOzRnUv79s

It’s the tapping noise that only seems to happen at just off idle. It’s most pronounced then. After a few more RPMs, the oil pressure pegs and it isn’t audible. But the fuel is also flowing more.

Any thoughts on the tapping/ticking sound? I’m willing to proactively pull the injectors and do a pop and balance job on them, but I’m also willing to pull the cam and swap lifters. I need a new VC gasket anyway on this new to me car.

Drives and runs beautifully, has some dragging brake issue but otherwise really great. But this tapping is noticeable much more than other cars I own including higher mileage 602 engines.

barry12345 · #2 05-03-2022, 01:19 PM

Disable each injector line. One at a time. Ticking still remains it is not an injector. Pretty certain of where the cylinder is the ticking is coming from. Just check the cylinders in that area. I believe lifter problems are fairly common on the 603s. Some automatic transmission fluid in the base oil will sometimes help.

Because they are right under the cam changing only one is not the best ideal. Too much work to risk a repeat. Still with a container of oil. You can test each one with a drill press and a rod. If many test as new in comparison to a new one. I might just clean them all internally that test well and just reuse those ones. After testing them again after cleaning.

Depends on the price of new lifters to some extent. Also if you see a lot of sludge in the engine. An oil passage to a lifter may be sludged and obstructed.

I like it when I pull a valve pan and the head is clean. I go into this as you do have to pull the camshaft to deal with lifter issues on the 603 I believe, Never owned one myself or worked on one. Old cars are just a hobby to me.

dieselbenz1 · #3 05-03-2022, 02:44 PM

Disable your egr and see if it goes away.

87tdwagen · #4 05-04-2022, 09:10 PM

Good advice provided above.
If a lifter tick , switching to a synthetic blend or fully synthetic oil will likely minimize the tick by facilitating the lifters to pump up quickly.

When listening to the injectors with the stethoscope, I find that placing the probe right at the body half way point on one of the flats gives you the best feedback. You want a consistent rhythm on all of them. Lifters are best probed from the centerline of the valve cover, harder to hear, but consistency or lack thereof is the tell.

JHZR2 · #5 05-05-2022, 10:13 AM

Quote:

Originally Posted by dieselbenz1

Disable your egr and see if it goes away.

Why would EGR play into this?

If I disable EGR I lose boost (for now, will install pressure operated wastegate)

JHZR2 · #6 05-05-2022, 10:16 AM

Quote:

Originally Posted by 87tdwagen

Good advice provided above.
If a lifter tick , switching to a synthetic blend or fully synthetic oil will likely minimize the tick by facilitating the lifters to pump up quickly.

When listening to the injectors with the stethoscope, I find that placing the probe right at the body half way point on one of the flats gives you the best feedback. You want a consistent rhythm on all of them. Lifters are best probed from the centerline of the valve cover, harder to hear, but consistency or lack thereof is the tell.

I’ve had bad lifters before and syn oil doesn’t necessarily help unless it is an oil flow at cold start issue. If it’s pressure or occluded flow, or wear, synthetic isn’t going to help. Apparently lifters are a weak point on these engines, and I’m not opposed to replacing them and perhaps even doing a preventive HG replacement.

I haven’t had much luck with mechanics stethoscope on the injectors but I’ll try the flats, I usually tried other spots from the top downward. To a great extent my hope was that the characteristic of the sound would be an identifying attribute to some folks on here. Various engines have various ticks and taps.

Cracking injector lines didn’t help much and is a big mess since this is most audible just off fast idle, so I need at least three hands but only have two. I do intend to get the injectors popped and balanced since I don’t have a record of it being done.

87tdwagen · #7 05-05-2022, 01:51 PM

Quote:

Originally Posted by JHZR2

I’ve had bad lifters before and syn oil doesn’t necessarily help unless it is an oil flow at cold start issue. If it’s pressure or occluded flow, or wear, synthetic isn’t going to help. Apparently lifters are a weak point on these engines, and I’m not opposed to replacing them and perhaps even doing a preventive HG replacement.

I haven’t had much luck with mechanics stethoscope on the injectors but I’ll try the flats, I usually tried other spots from the top downward. To a great extent my hope was that the characteristic of the sound would be an identifying attribute to some folks on here. Various engines have various ticks and taps.

Cracking injector lines didn’t help much and is a big mess since this is most audible just off fast idle, so I need at least three hands but only have two. I do intend to get the injectors popped and balanced since I don’t have a record of it being done.

Agreed that the synthetic doesn't necessarily cure it, but it does have a mild cleaning effect that helps with a possible occlusion. You can get the same benefits from some trans fluid or marvel mystery oil too.

If you do a diesel purge, you may notice a difference in the sound, leading more to injectors rather than lifters. The lifters are a bit of a weak point, my OM603 has a slight lifter tick, has been that way for at least 100k miles. When I replaced my HG I had the head, cam and lifters checked at the machine shop, and they all worked fine, pumped up well. The tick was gone for a few thousand miles, but then came back. For me, not worried about it, none of the lifters showed any undue wear after 300k miles so I leave them alone.

Good luck