AUGH! Please help me with valve adjustment tips! = broken valve guide - Page 3 - PeachParts Mercedes-Benz Forum

Govert · #31 02-15-2012, 10:14 AM

Quote:

Originally Posted by vstech

so... on the MULTITUDE of motors on this site, when the valve does NOT rotate, it's a sign of stuck rotators? worn valve faces/seats? HMMM...

anybody with the FSM know if the spring wrench is supposed to TURN the valve face during adjustment? interesting...
maybe on a newly purchased car, or one that's been too long between adjustments, set the gap, then rotate the valve, then start the motor, then repeat... hmmm....

I have several 30mm sockets, I could cut a few sections off of it, and weld them to a handle...

I don't know if a non-turning valve is a sign of a non-working rotocap. It depends on the friction force of the valve adjusting nuts vs. the valve spring force.
The spring wrench should not turn, but I usually see it moving a bit until it blocks against a injector, cam tower or thread of the valve cover.

Quote:

Originally Posted by Army

@Govert - at how many miles did they stop working on your engine?

Do you think that if they weren't trapped in those muck capturing recesses and were kept cleaner they might have lasted longer?

When I spoke with the machine shop / engine rebuilder who did the work for my engine I think he said that in his experience they didn't fail that often. So long as they move freely they're good.

EDIT - some perspective perhaps? Mine were all good at about 100,000 miles

My engine has run about 200,000 km (roughly 125,000 miles) for certain, probably more. Even the working rotocaps didn't feel as springy as the new ones. The non-working ones weren't springy at all, but they all could rotate. I did a compression leak test on my engine and you could hear when you rotated the valves that some of them weren't worn evenly. I could hear air leakage increasing and decreasing when I turned the valves, so the non-working rotocaps did have an effect.
They would probably last longer if they weren't in those recesses, where there is an oily-soot build up, I've heard that from an W123 expert too.

Quote:

Originally Posted by Army

As far as I can see the FSM doesn't say that the 30mm cap should turn. Even chapter 05-250 which says that the rotorcaps should be replaced on high mileage engines does not specifically say make sure that they still turn. Well it doesn't say so in the English version. I understand Govert uses the original German version quite a bit. I have a copy too but need to start Windows to access it. I usually save up my German FSM reading so I only have to suffer microsoft products once in a while! (I'll put it on my list)

I have to start Windows too for my German FSM. It doesn't say so either, it is sort of implied if the FSM says that they should be replaced on high-mileage engines. The only question is: what is high mileage according to MB? The original service booklet goes up to 200,000 km, so perhaps that is considered high mileage.

Stretch · #32 02-15-2012, 12:51 PM

O to have access to all of those service bulletins... may be there is some post official FSM-like advice there? I doubt if I'll get to see them.

charmalu · #33 02-15-2012, 01:09 PM

Here is a DIY on making the third wrench.
http://www.peachparts.com/shopforum/diesel-discussion/180280-valve-wrench-info.html

Charlie

Govert · #34 02-15-2012, 01:24 PM

Post-FSM advice on what exactly?

Stretch · #35 02-15-2012, 03:37 PM

Quote:

Originally Posted by Govert

Post-FSM advice on what exactly?

Well they may have, for example, decided that after so many miles as in XXXXXX miles rather than "at high mileages" you are no longer advised to change the rotorcaps but instructed to change the rotorcaps - I don't know - things get revised - recommendations change. The instructions in the FSM get superceded?

Govert · #36 02-15-2012, 04:27 PM

Don't forget that the advice is part of the replacing the valve springs. The rotocaps are easily checked once you remove the valve springs. In general it doesn't really matter if the valve stays in one position, as long as you don't turn the valves during valve adjustment. At the engine overhaul (for late OM61X-engines at 400,000-500,000 km) valves, valve seats and rotocaps could be changed. Don't forget the dealer usually didn't see the really high-mileage engines, fleet owners did their own maintenance, second or third owners went to independent garages, people who drove a lot, went to specialised overhaul companies.

I found this piece of information in the FSM of the Heckflosse:

"Bei undichten Ventilen erst nochmals das Ventilspiel kontrollieren und bei Ventilen die eine Ventildrehvorrichtung (Rotocap) haben, die nicht mehr funktioniert, genügt es vorerst eine neue Ventildrehvorrichtung einzubauen. Die Ventile dichten sich durch des Drehen wieder ab. Um mit Sicherheit einen Erfolg oder Mißerfolg festzustellen. ist eine weitere Dichtheitsprüfung nicht vor ca. 3000 km vorzunehmen. Wurde keine zufriedenstellende Besserung erzielt, Zylinderkopf abbauen und Ventilpartie bearbeiten." (0-05/3)

It means: if you have a leaky valve which has a non-working rotocap, replace the rotocap first. The valves will stop leaking because they will start turning again. After 3,000 km check again. If it still leaks, do a valve job.

The advice that you have to change the rotocaps on high-mileage engines was also in the W114-115 FSM. That leads to the conclusion that "high mileage" is more likely to be 100,000 km than 300,000 km.

leathermang · #37 09-12-2014, 09:02 AM

This is a good thread..... lots of good information...
One thing it shows... since rotators are cheap... anyone who does a valve stem seal job... should put a new set of ( cheap ) rotators.... and I recommend SPRINGS... as they are also cheap compared to the labor of getting all the stuff off to redo the valve stem seals.....
Army = Stretch .. I think both show up in this thread... maybe not... but ' Army ' still shows in some old posts..
Valve rotators were a wonderful invention... as the heat valves are subjected to varies across its surface.... rotating them each time they are activated keeps the valve SEATS round also...

Some important facts about the valve adjustment wrenches...

the third wrench WITH the little stand... which keeps it in place for those who only have two hands... is very helpful when things get hard to do.. like the back cylinder in my 617 wagon... I had to button up everything.... to drive to the dealer to get the proper wrenches to finish the job..

THIN wrenches...
of the PROPER ANGLES..

these are important considerations for the valve adjusting wrenches due to the thinness of the nuts...
AND you may need to pull one wrench against the other..

THUS is becomes important that they slide past each other ...