OM617 Valve Rotators and other CH questions - PeachParts Mercedes-Benz Forum

Les Izmore · #1 01-04-2017, 12:38 AM

I finally got the engine out of my smashed up '85 300D, tore the engine down and got the head off to the machine shop, and my head is spinning with questions, what started off as a "reseal" is quickly turning into a rebuild. But this thread is about cylinder heads so let me stick to that.

I found a good local machinist who spreks a little doitch and seems trustworthy. The good news is I am crack free

and my cylinder head has no cracks either. And this is from an engine with 242k on the clock thats been sitting for years now, apparently with very old antifreeze or possibly just water, see the rust plugging up the water jackets in the photo. I think I got it opened up in the knick of time.

Anyway, the cleaning, magnaflux, valve job, and milling the head (if needed, he still had to check) is going to run $325, with me supplying new valve guides, springs, and seals. Seemed a little pricey but hey I didn't have to ship it somewhere. I am also replacing the adjuster lock nuts, (would like to replace the adjuster nuts too but for $5 apiece ???)

I would like to replace the rotocaps too and I cannot find them. They say TRW Germany on them, does this mean they have already been replaced? (Does this also mean TRW is a german company? I never knew that) If someone has the part number I would greatly appreciate that, any wisdom on replacing or not replacing them is welcome too. I never heard of valve rotators before today but they sure seem like a great idea! And I hope these valves rotate on for a long long time.

I also had a hard time finding the 30x36x2 AL crush washers for the temp sensors (why are there 2 sensors of different lengths?) and coolant line connections, I found them at a company called Maryland Metric, haven't called yet though, see other attached. They don't come in the head gasket kit, do they?

Anything else needed for a refurbished head?

Alec300SD · #2 01-04-2017, 01:04 AM

The Fischer Plath brand of aluminum washers (in the size you are looking for) are available from our sponsor at 25 cents each:

Aluminum Washer - 30 X 36 X 2 mm
Part #: 30-X-36-X-2-AL-M131

1985 Mercedes-Benz 300D Base Sedan - Miscellaneous & Hardware - Page 2 (about halfway down the page)

Les Izmore · #3 01-04-2017, 02:35 PM

found the rotocaps at the dealer part #000 053 1235 at $33 each. I guess I jumped the gun a little, the machinist says they are not a normally replaced part and the existing ones checked out good so I'll save a little there.

It turns out some of the adjuster nuts are beat, so add another $50 to the job to replace them all.

Thanks Alec300SD for the part number on the AL rings, any idea on the torque on those monsters? they were pretty tight coming off...

Stretch · #4 01-14-2017, 02:54 PM

Torque limits are all published in the FSM which is available for free over on startekinfo