Projekt langsam: Mercedes W126 300SD

I hope to chronicle my (hopefully successful) engine swap in this here thread. Not only will the swap be slow-going, but of course the car itself will be slow, too, hence its name. :D

For $1,000, I get the car, two engines (one bad,) and three transmissions (one bad.)

So, here is how I found it, as you may know:

It's been sitting in its current position since 2009. That's when the PO starting the engine removal process, and gave up when he was unable to remove it with the front wheels on chocks. So that's where it sat, untouched for the last 6 years. The brakes are currently frozen solid, and the interior has the faint smell of mouse, but it seems to be in good shape otherwise, which I'll admit sounds odd given its current state. I am concerned that he didn't label anything, so at this point I am definitely in the dark.

So yesterday I got it off of the chocks, which, I think should make getting the engine out possible. And that's when I found out the the engine hoist wouldn't lift the engine more than a few feet. Hmm. It holds the engine, so I am hoping that some hydraulic fluid should get it back in the game. Here's hoping.

You don't see very many black interiors from that generation of MBZ. It's very handsome. Subbed for turbodiesel content.

And it's out! A quart of hydraulic fluid, the removal of the tach sensor and the starter wires, and removal was mostly harmless. The damper for the steering took a hit, but all else seems OK.

Now I have some cleaning and maintenance to do...

Now is a good time to wash that engine bay.

What's the final drive in those? Would a higher (numerically) gear set make it more fun to live with around town? Even at the expense of highway top end?

(Not sure if that'd push it out of its torque curve or not)

The lack of electrical connectors left in the engine bay is quite beautiful.

Can you crank up the boost like diesel truck guys do? Make stupid torque figures? That would make the final drive ratio irrelevant. And be a lot of fun. Be the first time I have ever supported rolling coal.

In reply to Dusterbd13:

I think factory boost is 13.5 and cuts off at 15. You'd need to add fuel with the boost increase and then there are other considerations to take into account like EGT's.

(I read this, I'm not MB Diesel expert)

Dusterbd13 wrote: Can you crank up the boost like diesel truck guys do? Make stupid torque figures? That would make the final drive ratio irrelevant. And be a lot of fun. Be the first time I have ever supported rolling coal.

Nope, not easily. You have to send out the injection pump to be rebuilt with larger elements to be able to make any decent power. I think the rebuilds run around $1500 or so.

The final drive should be 3.07, which is perfect for my needs - mostly highway.

Cleaning is next, but I am not going to be able to get over there again until next weekend. Have to autocross the wagon on Sunday, which means shocks tomorrow.

And mazdeuce, you have no idea how thankful I am of that.

In reply to EvanB:

Yeah, it's not cheap from what I've seen. Seems like it might be a good business to get into!

Good ol' Langsam has not been forgotten, lest you think my lack of board activity directly correlates to his progress. Seals have been replaced, brakes have been replaced all around, and the engine is pretty much ready to be dropped in. I've also started tearing into the original engine, and, so far, everything on top looks OK. We'll see what it looks like when I take the head off. I hope to have the car up and running before Christmas. We'll see how that goes.

In to see how this goes, have always liked old MB's, but they are either ridiculously expensive to buy in good condition OR to neglected beyond my skill set and slightly less expensive in my area.

OK, so I lied. It did not get done before Christmas, nor my surgery. The weather was nice today, so I got a ride over to look over the car and to see if my mothball attack had staved off any mice invasions. It indeed had, with the unfortunate consequence of an old Mercedes smelling of mothballs. Gross. Bright side, it beats the aroma of mouse lemonade and chocolate sprinkles. Filled up the rear tires with air, and huzzah! The car rolls freely when I push it one-handed. Brake systems are holding fine. Here's a very dirty picture to motivate me.

I drove one of those for a few years, it was pretty reliable and not annoyingly slow unless you have to go up hills on the freeway. While you have the engine out it might be a good time to change the oil cooler lines if needed, they are not cheap but if one fails the engine will likely be scattered in pieces on the ground before you can shut it off if one fails at speed. Other than that, if the timing chain isn't too worn (you can tell by how much it has stretched), the engine should last a very long time. If they are well maintained they can go 800k miles before they lose too much compression to start easily or run well anymore.

Timing chain on the replacement engine is, with a cursory check, nice and taut. I have two sets of oil cooler lines, and you better believe that they will be gone over thoroughly. Once the engine is in, I'll be performing a lot of maintenance on it, including a purge and checking the valves, to name two.

Are you gonna run veggie oil or bio-diesel?

Best car I've ever road tripped in was a 300D, enjoy it!

In reply to DrBoost: No plans to at the moment. I won't rule it out, but from what I've read online, everyone seems to think these cars don't like it, or maybe they're doing it wrong. Regardless, I intend to just run diesel for now, get it back to Stage Zero as it were.

Update!

I finally feel pretty confident working on the car again, so yesterday's plan of attack was to swap wiring harnesses. Whomever owned the donor engine before the PO got it did some horrible, horrible things to the wiring. Not one to muck about with unpleasantries such as fires, I decided to swap the wiring over from the bad engine, whose wiring looked to have been unsullied.

Here they are side by side, the good harness is on the left, and the bad is on the right:

Swapping was pretty easy, but cylinder #3's glow plug lead twisted out of the glow plug, so now there's that. The end is near, and, fingers crossed, it should be running by summertime.

I probably just jinxed myself.

Great job, duderino. Plan a trip down to KY after its together and we'll look it over and drink copious amounts of good beer.

Oh, I am in!

Next on my agenda is tires, but finding anything remarkable in 14 inches is going to be difficult. Probably going to have to go with Michelins.

Engine is in!

Mostly, anyway. Hit a little snag when the PO couldn't find the motor mount bolts, so I am currently waiting for those to arrive.

I also discovered that the good engine came with a K&N air filter. Though I am not too sure what good that really did, I'll take it.

A+

And here is how it looks minus nearly a decade of dust. It won't be done before I go overseas, but at least it looks nice.