OM603.97 Head Gasket Replacement - What Parts Should be MB Only?
 

As mentioned in an early thread after buying my 350SD, it runs beautifully, but I accounted and planned for engine work to keep the rod bender happy.

Putting 2000+ miles on the car and resolving a tire wobble quirk has made me decide to keep the car for the long run. It starts, runs and drives beautifully. But I do see a teaspoon of oil in the recovery bottle after 500 miles. Therefore I’ve premptively decided to do the HG, and since my preferred and trusted shop is also a Bosch service shop, I’ll have them seal the IP while at it.

Ive looked through a few threads. I want to be sure that I’m very clear on what irreversible, long term items I need to specifically request are MB only parts. Essentially, I don’t care if I can save some money with Victor Reinz VC gaskets and such, but certain items should only be MB parts. I’d appreciate recommendations on the list.

Initial cut of required OE MB parts:
- head gasket
- head bolts
- valve seats (if necessary)
- tc guides (if necessary)
- timing chain (if necessary)
- ip seal kit (or should this be Bosch?)

Not sure if TC is really in play at 115k, but I figure they’ll initially line up the timing marks on the cam and harmonic balancer, and if it’s more than a small amount off, it seems like it’s as good a time as any, no?

Anything else that should be an MB part only?

Thanks!

When I did my 300SDL, I used Victor Reinz simply due to the unknown condition of the rest of the engine and the fact I'm still running a #14 head. I used an OE upper chain guide with VR head gasket and VR head bolts. Been fine so far and I don't drive like Grandpa either.

Make sure you use Mbz oil, lubricant, o-rings, coolant, screws, tools etc. I have done 2 head R&R, at least 6 hd gasket replacements on 601 and 603 engines and never once specifically use mbz parts. In the grand scheme of things, it doesn't matter. I reuse all the head bolts. It is not my money so it doesn't affect me. I am just telling you my experience.

Valve stem seals would be the top of my MB only list.

Why would you need valve seats at 115K miles? For guides and seats I’d go with what a reputable machinist says, MB or not. I would think proper installation is more important than brand.

Sixto
98 E320s sedan and wagon
02 C320 wagon

There's silly then there's items that in the world of questionable parts, are likely to ensure a favorable outcome.

My read was that MB had redesigned the HG a few times in the 3.5L. So it's likely that I'd get the latest. Who knows if/what the aftermarket has. Maybe better, maybe not. But that's precisely why I'm asking the question.

If Head bolts are torque to yield, I'd prefer to do it right on a relatively pricy job than to save a few bucks and regret it when something doesn't go right.

Because I used the wrong term. It was the seals that I saw some pics, maybe yours, that showed a marked difference in the parts. So didn't mean seats. Is it prudent to replace the seals at 115k just as a matter of practice?

I used a victor reinz head gasket and have had no issues on my om603. Measure the bolts and if they're not stretched more than I think 2mm you can reuse them per the factory service manual. I think the most important thing is following the torque procedure and if you remove the cam follow that procedure as well. These cams will break.
From what I've read the one thing that is important to use mbz parts in this would be your valve stem seals. It seems the aftermarket seals are a different design. I have not done valve stem seals yet so this is not from experience. There is several threads on here on the subject though.

I used victor reinz HG kit, valve stem seals etc. I meansured the head bolts and they were all within spec so I reused those. I actually had 2 sets of used head bolts and every bolt in both sets was below the max length by several MM. No reason to waste money.
http://www.peachparts.com/shopforum/...uesequence.jpg

your going to do this over a tea spoon of oil?

anything with a turbo will have blow by, its normal. unless your pushing out more than a gallon (high low mark) between your fuel interval or have actual on the ground leaking or visible leaking if not i wouldn't worry about it. honestly you could probably change your driving habit and the oil would go away. or just compare the amount collected between city to freeway miles ect. freeway will push more oil.

plus you dont even know if the HG will fix the issue. i would check the head and valves for any sort of "compression leaks before the hg and rings. obviously if your doing head work your doing a hg too but to just blindly decide to do one.. do a compression test before you pull the head lol but if thats the route you plan to go use MB stuff for the HG and head bolts because it will be the best made and most engineered/updated part. the bolts are defiantly torq to yield and pretty tiny at that too so i wouldn't even think about reusing them even if they are still with in spec for stretch. .

Cannot agree with you more. I do things on the cheap, very cheap, but I follow the FSM procedures and it has never failed me. HG replacement is not rocket science, everything mechanical has a big tolerance spec. My take is that another shoe will drop with the car long before the HG will fail again.

Yeah, just like the #14 head was the best made and most engineered. Good point LOL
But Mercedes head bolts are the best made and most engineered headbolts. Why wouldn't you follow the Mercedes engineers advice?

can you go buy a 14 head at a dealer ship? or do they sell you a 22... same goes for the HG.

i would buy new head bolts because its cheap assurance and because of the actual size of the fastener and torq applied to it... even loosening them you get a pretty good idea how much torq they are under. reality tho is im going to find an arp stud and fastener combo that works when i switch heads.

what i said is a legitimate thing fiy. #14s are bad cause people are stupid and run them dry and or hot. subsequent revisions were done to address peoples stupidity, but for the most part the actual head does not change... no port valve or spring changes for longevity... i can assure you they just dont break haphazardly, ive beat the crap out of mine and its fine sooo i would say its pretty well engineered honestly especially if the engine remains stock and is driven like a mercedes.. (neither of which i do)

that being said i do have a #17 which is ready to be messed with.