Finally, after nearly four months, the '81 wagon is back on the road. I was held up for nearly six weeks when we had 24 inches of rain that kept me from getting to the parts car. The machine shop then had the head for a month.

At 320k miles, the engine lost compression in cylinder #3 . Leak-down confirmed a bottom end problem, probably broken rings. Or at least two lenghtly MMO soaks did not improve anything. Nothing was evident upon removing the head, although I got some rain on the block and water pooled in every cylinder except #3 . Kind of looked like the piston to cylinder clearance was bigger, but I didn't measure it or pull the piston.

Really, kind of a surprise for a "million mile engine". I have records from the beginning of faithful oil changes every 5-6k miles.

At any rate, I had to re-use the original wagon head as the parts car was a sedan. The machinist looked it over for cracks and trueness and checked the valves and seats. The guides were worn and a couple of seats were beat-up. He didn't have the tools to replace the guides, so under the circumstances (replacement block @260k and of unsure condition) I had him touch up the bad seats, install new stem seals, and call it good.

The car now runs very well, with very good power and acceleration. I had a bad leak at the modulator which I was able to fix by replacing the newer style with the original, older-style which was on the parts-car tranny. While the original tranny worked OK, it was leaking at the front seal and I knew from receipts that the parts car tranny only had 100k miles on a complete rebuild.

Some random observations:
1) I read that an MB engine can be removed with a 6 foot sling, and since I was taking it out with a skid-loader, that's what I did. With the sling just forward of the mount arms, you get the extreme angle needed to clear the chassis. You need to pull a jack forward under the trans to keep it from scraping. I misjudged and bent the steering damper, but I had an extra.

On one engine I had the head off and on the other the head on. Manifolds off. When I pulled the head, I made the mistake of allowing the head to twist and it caught the chain tensioner rail and bent it. I also neglected to undo the bracket that holds the turbo oil line to the head and bent this also. Not too big of a problem as I used the parts car turbo line and had a new rail available.

2) I neglected to follow the advice to use the injector hard lines to orient the IP when I swapped the original IP onto the parts car engine. I swapped them because the parts car had sat for five years and I didn't know what condition it was in. Since I had the oil filter canister off to change the gasket, I didn't want to have to swap IPs with the engine in the car.

So after drip timing the IP and tightening the nuts, I realized I was off a spline or two when I went to install the hard lines. A real PIA to rebend each line to fit the new position of the IP. The lines had to move almost 3/4 inch.

3) There were subtle differences between the '81 and '83 engines. The '81 passenger side engine shock was the type that slides into place where the '83 had the contained bolt-on type. The trans cooler line mounts were different at the back of the engine. The newer engine had an opening in the alternator adjusting plate for insertion of the spacer tube. And the injection pump on the '83 had a plate on the side behind the lift pump where the '81 had a bolt.

Things that I would have done differently if I was the original MB engineer:

That stupid oil pressure line that has to come off the instrument cluster and through the firewall to remove an engine.

Those nasty aluminum oil cooler fittings. They are good for two tightenings and two tightenings only. I cut the lines off the parts car cooler with a cut-off wheel to not have to turn them off.

The fan bolts. I mean, really--we all want to live in a better world.

All-in all, a satisfying project. Time will tell how much life I'll get with the 320k head on the 260k block.

__________________
1981 300TD 310k miles
1970 280sel 172k miles
1966 230 Fintail 162k miles

"Where are we going? And why am I in this hand basket?"

Definitely need a load leveler particularly if you are doing the engine removal alone

I've always looked at the lifting eyes on the OM617 and thought to myself "now that's not how Isambard Kingdom Brunel would have done it" - they look far too flimsy to me (thought they've not failed yet!)

__________________
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!