Thanks again to all. I am going to have the upper guides done this weekend and leaving the chain and the tensioner to the discretion of the mechanic (encouraging him to use the criteria several of you kindly set out). I'll follow up on the findings and how it goes.

Being that you need to remove the p/s pump, alternator, distributor and cam sprockets to replace the upper guides, it ends up being the bulk of the work. I'm lobbying to change out the chain and tensioner too, since in IMO, it's the easiest part of the job and it would make the job complete.

I didn't realize the guides would require all that; you're probably right. I guess aftermarket tensioner is a bad idea? There is a huge difference in cost on that item.

I would insist upon genuine Mercedes parts for all of this repair no matter how good they say the aftermarket parts are if that is what they try to sell you. It's just not worth the risk.
Just my 2 cents worth.

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Mercedes Benz Master Tech - Retired

And a side effect, your idle will be much better with a new chain if yours is streeched excessively

Last time I did guides the distributor stayed in place. BUT this could be an M116 vs M117 issue regarding deck heights. I also just replaced the tensioner rail liner. Unsure if MB still offers the liner for that separate currently.

I would rather a 30 year old, 100k+ OEM tensioner be in my vehicle than some aftermarket BS. Oh wait, that is what I did and now I am creeping on 190k.

Swag guide rails are good, I have used them in BMW M30s as well as my OM603 and 617. I would run them again. Iwis are the chains I use.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

If you are going to buy the parts then add 20% of your cost to his invoice. Why do you think the mechanic should be screwed out of his mark up?
Anziani

Agreed.

Plus how would the tech offer a warranty? That is right, they will not.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

I thought it only fair to share the rest of this saga, to date, as much as it pains me to tell it (and no it is not a need-a-new-upper-engine bad story but it has been a pain....) The advice on here varied in parts so I guess I can say I followed most of the recommendations. I chose a shop who serviced a 300sdl I recently bought according to the records; the guy I used to use retired. They had no problem with me using my own parts so I got an Iwis chain and MB upper guides and tensioner (all of which was about $500). Before they started they called and quoted $600 for labor, with a disclaimer that, given the age, there could be more for the unexpected (frozen bolt, etc). I said fine. They called back not long after and said the labor would actually be $2300. They mis-gauged it. I told them to put it back together as obviously they had no idea what the job done properly would entail. To their credit they didn't charge me. My small town is 90 miles from them so I had it towed to another primarily european car shop in that same area, who told me they could do the whole thing for $1060 plus tax, and I specifically asked if they'd use MB parts and they said yes (they said their warranty program would not let them use my parts). They did the job, seemingly all was ok, I drive it the 90 miles back home, and when I get to my driveway it is smoking like crazy and there is oil pooled around the front of the right valve cover. Oh, before leaving the shop I again confirmed MB parts were used as $133 for a MB tensioner seemed too cheap. He said "Oh I use a guy who has a lot of new old stock (ie that's how I can get MB that cheap)." Anyway, at least part of the oil problem turned out to be insufficiently tightened valve cover bolts but I now think I have some sort of probably more expensive leak in the rear. BUT IMAGINE MY, um, ANGST, while, in the midst of cleaning oil, I see a Febi ensignia on my tensioner!! And that's where I am. I cannot believe I've got a trunk full of MB parts and now I'm wondering if the whole job has been done with aftermarket parts which I tried SO HARD to avoid.

One question I have is whether that tensioner can simply be removed and the MB tensioner put on. Is it as simple as unbolting one and bolting on the other? If they swear the guides and chain are MB, and I could swap out the tensioner, that might get me to where I was hoping to be - but of course how can I trust whatever they say at this point.

ehm, you can have the Febi tensioner replaced with a genuine MB tensioner by someone who knows what they are doing, either you or a tech familiar with the procedure.

Hopefully, you are confronting the shop that performed the work using aftermarket parts while claiming the parts were genuine MB parts. Always best to have a written contract/proposal that both parties sign so there is no misinterpretation about specific details.

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Fred Hoelzle

Thanks. I spoke with the mechanic this morning who said it came in a MB box, and that the supplier claimed to have been duped. They are going to replace and make sure the replacement is mb.

As a euro parts guy, I would not be shocked to find a febi part in a MB box at all in 2018. Don't shoot the mechanic or parts guy until you're sure they screwed up, which is always possible.

You should also get that kinda stuff in writing before hand imo, when I write up an invoice for mechanical work at the joint I work for, each line item on the itemized invoice is a PN and it has what brand it is. Sloppy ass lazy shops lump stuff together on the bill often times.

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One more Radar Lover gone...
1982 VW Caddy diesel 406K 1.9L AAZ
1994 E320 195K

Just an update: I think all this has a happy ending. Got the Febi tensioner replaced with MB, all working well there. The oil leak actually turned out to be a cracked oil filter housing which apparently had a lot of JB weld on it. I had the good fortune to find one from a 560SEC with 34k miles (had to wonder what happened for that car to be parted out?!), and all seems to be well - a month after I started down this road! Thanks again for all the valuable input!