Hi Charlie,

Thank you, you're always very helpful.

I actually have the correct adjusting nut wrenches, that's not the problem.

The problem was that I had a stubborn valve where the valve kept turning when I was trying adjust the clearance. That's what the "Valve Spring Hex Cap Holding wrench" is for.

I haven't found anything else that is designed to address the problem I just described. Looks like they are around $50.

Sincerely,

PE

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83 240D - 4 speed manual - Manilla Beige
189K miles, Tachometer mod, cool wooden shift knob from PeachParts, CocoMats, Original factory paint, manual windows, manual sunroof. Starting to add AudioWrap to this car too!

Bed time? Nah it was just lap top in the kitchen cooking dinner for the children time... I'm only 9 hours ahead of you Charlie. We're closer than you think - you have been warned!

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Does the 240D have valve rotators? Is it possible that I messed one of them up by rotating the valve during adjustment?

Thanks,

PE

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83 240D - 4 speed manual - Manilla Beige
189K miles, Tachometer mod, cool wooden shift knob from PeachParts, CocoMats, Original factory paint, manual windows, manual sunroof. Starting to add AudioWrap to this car too!

They have that star looking thing visible in the pic on the right.

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83 SD

84 CD

HI there, I don't see the pics... what is the star-looking thing?

What picture?

Sincerely,

PE

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83 240D - 4 speed manual - Manilla Beige
189K miles, Tachometer mod, cool wooden shift knob from PeachParts, CocoMats, Original factory paint, manual windows, manual sunroof. Starting to add AudioWrap to this car too!

Sorry. I'm confused. My question was does the 616 engine have any auto valve rotation devices that could be thrown off by my rotation of the valve? I read a post that indicated that certain MB engines have valve rotators, and that by NOT using the "3rd wrench", you can disable the rotators, and mess up your valves.

Can anyone clarify?

Thanks,

PE

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83 240D - 4 speed manual - Manilla Beige
189K miles, Tachometer mod, cool wooden shift knob from PeachParts, CocoMats, Original factory paint, manual windows, manual sunroof. Starting to add AudioWrap to this car too!

i actually had planned on doing a valve adjustment tomorrow on my 240D and also was using the Diesel Giant guide (which doesn't mention any of this). just made my two bent 14mm wrenches tonight. but now i'm all confused. is the 'screw-driver-jam vs. valve-spring-cap-wrench' decision one that i will definitely have to make, or do the valves only spin in some scenarios?

The valves only spin in some scenarios. Apparently the vast majority of them never spin, and it's only some of them that have this issue. It manifests itself as when you try and adjust the clearance, the valve spins (you can see it), and if you aren't thinking about what's going on (like I wasn't), then you won't realize that you cannot adjust the gap unless you keep the valve from spinning around.

The Hazet wrench kit has the 3rd wrench, which pretty much looks like a 30mm socket that's been chopped up and has a handle welded to it (that's the concept anyway). It serves only to grab onto the hex head cap on the valve springs, and keeps the valve from spinning as you adjust the gap. The FSM shows the use of the wrench clearly a couple of posts above.

Sincerely,

PE

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83 240D - 4 speed manual - Manilla Beige
189K miles, Tachometer mod, cool wooden shift knob from PeachParts, CocoMats, Original factory paint, manual windows, manual sunroof. Starting to add AudioWrap to this car too!

The OM616 and OM617 engines have some common parts. One of these shared parts are the "rotator" bits that are fitted beneath the valve spring - I've added some more lines to the picture posted by toomany...



There aren't many ways to mess up these little rotating things at the bottom of the valve springs. They are most likely to suffer from a build up of crud as they sit in a recess in the head and there isn't any flow of oil going past them - not that really matters in most cases as far as I can make out. If you were rebuilding the head then it would be a good idea to clean them out - but under normal routine maintenace nobody is going to bother with them.

I'm sure that in 99.9999999% cases it is difficult to mess them up whilst adjusting the valve clearance so long as you aren't jamming great bit bits of metal down through the valve spring!

I think it is most likely that you will damage the valve guide by jamming foreign objects down through the valve spring.




Now please don't let this get out of hand. Be careful and I'm sure you are all going to be OK =>

What happened to my engine was undoubtedly caused by a total f$%^%^^&&ing idiot. I think that this is a really REALLY RARE OUTCOME

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__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

Those rotaters are called Rotocaps. You cannot damage them by rotating the valve, but what does happen is that the rotocaps stop working over time. The valve stays in one position and wears in one position. If you turn the valve, the valve doesn't close anymore.

It is advised that you change them if the engine has a lot of miles:









Some of my old rotocaps didn't work anymore when I replaced them, some of them still worked to some degree.

Army, THANK YOU!

That is a brilliant post, and explains the answer to my question perfectly, concisely, and accurately.

I now have a tiny bit more knowledge jammed in my head, thanks to YOU!

Sincerely,

PE

__________________
83 240D - 4 speed manual - Manilla Beige
189K miles, Tachometer mod, cool wooden shift knob from PeachParts, CocoMats, Original factory paint, manual windows, manual sunroof. Starting to add AudioWrap to this car too!

I forgot to post these up again

They show the dimensions (well each square is 2.5 cm) of the wrenches so that the more adventurous can make their own!





Occasionally these sets come up for sale quite cheap. I think I paid something like 30 euros for mine => you have to be patient and wait though.

__________________
1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

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...

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1987 560SL convertible
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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)

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

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.

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.


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.