My brother's SDL has had a chronic vibration problem for several years. We've replaced the belt, the PS pump, alternator, and belt tensioner pivot to no avail, it still hammers annoyingly at idle. Otherwise runs great.

I finally suggested he verify that the front crank pulley was solidly attached, as I was out of ideas for anything else (fan, water pump, and AC compressor bearings seem to be good). So he pokes around and finds nice tight bolts, but after he shoved around on the harmonic balancer, it ran find for a little while then started to shake again. Also found mucho thrown oil everywhere, so decided that the balancer and front seal needed to be replaced.

Sounds pretty simple, eh? Ha ha! First problem was that we borrowed the appropriate tools from our mechanic friend and they didn't work -- different setup than the older engines. Balancer was something like $300 with shipping from Germany (I guess they don't go bad often), but with no way to hold the crank as Hans didn't have the factory tool, we welded a chunk of angle iron to the old balancer to use it as a holding tool to unbolt the crank hub. That worked fine, but after we ruined the old seal pulling it out, we discovered that we had gotten the wrong one (parts mixup) and no one in town had the correct one. So there the car sat, all in bits, radiator out waiting. This was last Sat.

My brother took the radiator down to the rad shop to get it cleaned out, it was half blocked with dead bugs and crap -- I strongly recommend you pull the rad next time you change coolant and clean it on one of these cars! Nasty, made worse by all the thrown oil.

Now, my brother also wanted to change the folded stainless thing between the two parts of the manifold, as it was blowing soot. Should be easy, right, just compress and push out, push the new one in, clamp up. Wrong, there is a pipe in there too, fitting into the manifold parts. So at least the front part has to come off.

No dice on that, either, the whole setup comes off -- nicely, you can unbolts off the turbo and just take off the return pipe and the two parts of the manifold after you remove the EGR adapter. Lotta hard to reach nuts and bolts, but not too bad ----- until he found the broken exhaust stud, same one that was broken on my 300D head last winter. The last one back by the firewall, almost impossible to reach, have to use a mirror to even see it.

He found a right angle drill and drilled it, but broke off an EasyOut in it (as I expected, I told him to borrow Han's good ones), so a simple pipe replacement becomes change the head gasket. Sigh, another delay and $250. Where have I heard this before (last winter when it was cold as hell).

Got the head off on Sunday night with no major problems -- this time none of the head bolts broke and it lifted right off. Found nearly new cylinder walls, no blowby (the soot in the intake is dry, believe it or not!), and most of the gasket was sealing just fine. However, and this is why I suggested a new one couldn't be a bad thing, it appears to have been failing at the oil passage between #1 and the chain case. The main part of the oil leak wasn't the front seal, although that was probably leaking too, but the gasket at the chain case was definitely bad, the bolts weren't tight, just like my 300D. There was some oil in #1, too, not much, but I suspect the seal was going. No oil in coolant or coolant in oil, or evidence of leaks, but I think it was time!

Getting it all back in took the rest of the week, we finished up last night, to my great relief. While we were doing all this, the 300E my brother bought last summer as a spare car (his daughter is driving age now) decided to blow a head gasket out and leak coolant all over the place, so I lent my "new" 300D to my sister-in-law so she could get to work -- the TE is blowing heater blower fuses, so I can't use it, ether (replacement blower showed up today, but it's 16F outside right now....). I was reduced to driving my old 280 SE, which it limping pretty badly from wear, tear, old age, and disuse (i have a replacement engine waiting to go in).

Quite a week, although the 280 ran MUCH better after I found that one of the injector seals had disintegrated, causing an enormous vacuum leak. Still runs rough, I think I've got an injector sticking open.

Nothing like fun, eh?

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Old cars are tons of fun! Every project turns into an adventure!

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Sounds like a Mercedes pull-a-part reincarnated.

Nice work!

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Paul
Benz-less
I need an SDL !