1976 240d w115 has been sitting and is locked.

[C4rest]

I haven’t had a chance to pull the engine yet and see what all the damage is. But if it turns out to be really bad i’ll definitely look into getting a used one. I honestly did not know that there were different versions of the car. I need to see which one I have. Can I tell based on the VIN or is there a plate somewhere on the engine?

[gmog220d]

Assuming the car was originally a 240D, the first six digits of the VIN will be "115.117". The original engine would be OM616.916. You can see that number (as 616.916 followed by the serial) on the block, top rear LH corner just under the bottom edge of the cylinder head.

[Frank Reiner]

Originally Posted by indybenz

The main thing I'm NOT selling is the pedal box.

Should someone want a 123 pedal set w/new clutch master cylinder,--$90 shipped, lower 48.

[C4rest]

I just went out today to pull the engine. I decided to try and turn it over 1 more time. The thing literally just spun right over. The acetone and ATF must have worked! What should I do now? I’m going to oil and clean the cylinders and if I can figure out how, I’ll post pictures of it.

[Sugar Bear]

What to do next depends on the cylinder wall condition, pictures are needed. Great news that it freed up. Clean the walls really well, rotate the engine one turn and reclean the walls. Repeat this until the walls stay clean between each rotation. If the walls look good put a liquid in the cylinders and see how well they seal/hold the liquid over night compared to each other.

Keep the walls lightly oiled while doing this. ATF would work for this.

Good luck!!!

[Todd Miller]

LOL.......that's awesome man!

At this point, you'll want to assess the condition of the two rusted cylinders. Photos will help us, help you.

Be aware that even if the cylinders are okay "as-is," OR are good enough that they'd clean up nicely with a flex hone as I spoke about previously, that is no indication that the rings are ok.

The rings could be rusted solid to the pistons. Or sections of them could be rusted solid, while other sections are loose and able to flex outward to seal against the cylinder wall. AND....the oil control rings could be in the same seized or partially seized condition. Rings that won't flex outward and seal, won't create compression, and an oil control ring in this condition, will allow engine oil to get by, and you'll have an engine that smokes and burns oil.

Something to consider is that you could continue to let it sit with the 50/50 mix in it and hope that the rings would free up and start to play nicely. The other thing that can happen, is that the rings will free up once the engine is running, and you start putting some miles on it. It's all a gamble, but I've seen it happen.

If it were mine, I'd most likely bolt the head back on, with a new head gasket, put the whole thing back together, and see if it runs. If it does, I'd start driving it. If it didn't start, I'd feel stupid, but hey, I understood the risk.

The wise choice would be to remove the engine block, remove the upper pan, and remove all 4 pistons. Remove and replace the rings and clean the ring lands, flex hone the cylinders, and put it all back together.

Whatever path you take, remember that you've disturbed the timing chain and drive gear for the injection pump. The engine will need to be re-timed, so that the crank is at TDC for #1, the pump drive is at TDC, and the cam is at TDC for #1. Otherwise it'll never start in a million years.

[C4rest]

I think I’m going to just see if it runs. If it doesn’t then i’ll pull the engine haha. The two outer pistons cylinders have always looked good. They were all most at the bottom of the cylinders. I did see that the top of those cylinders had a blackish ring near the top of the cylinders which looks like soot. The two middle ones were luckily stuck to near the top. There is definitely some rust. I’m going today to clean them. Oh and the two outer ones held liquid for around a day or so. Right now I had diesel in the two middle ones to see if they leaked much. I’ve had that on there with the pistons at the bottom and it has gone down an 1/8 of an inch over 2 days. I assume that these ones are probably seized? I’ll take the diesel out today and put the 50/50 mix in it and then clean it.

[C4rest]

I’ll try to post photos today. I’ve take. a lot over the course of this to remember where stuff goes.

[Todd Miller]

I would say the rings for piston 2 and piston 3 are seized in the ring lands, either completely (all the way around), or partially. But you never know what the magic of the diesel fuel and then the 50/50 mix will do for them.

I had a 4 cylinder gas car, a 1962 190 with 4 speed on the tree. It had been left in a carport, 1/4mi from the ocean. The body was solid rust and the engine was completely seized. I was able to free that engine and get it to run. I then removed it and put it in a much nicer car, a '66 230. (that took some creative mods because the 230 had been a 6 cylinder car). The more I drove that car, the better the engine ran. I drove it as my daily, all over town, picking up my daughter from school, everything, because the constant change in load and rpm on the engine, would hopefully free up those rings and also re-seat them. There's no way that engine should have even run. After a few week, that car ran so perfect that you'd think I'd rebuilt the engine. I sold it a few months later, to a family at my daughter's school, and it's still on the road, 15+ years later!

I mentioned this before, but if you have really good compression in cylinders 1 and 4, and some compression in 2 and 3, you may find that the engine will light fuel on it's own, and as soon as it starts running and piston velocities come up, that cylinders 2 and 3 will start making enough compression to light fuel. So it might start a little rough, and smoke white for a minute, but then it'll clear up and you'll hear the other 2 cylinder join in. At that point, let it sit and run with the throttle propped open to something like 1,500-2,000rpm. Let it come up to operating temp and get the air out of the cooling system (that's an important thing, so leave the radiator cap off, heater valves wide open, and keep topping it up), and then just let it sit and run like that for a half hour.

[Sugar Bear]

Don't leave it unattended and running with the RPM's increased. An older diesel, especially one with a ring problem is a candidate to become a "runaway." Be prepared to shut it down immediately if it starts to increase RPM's on its own.

Good luck!!!

[C4rest]

I’ve heard of runaways diesels. I’ll be careful. I just drained all the diesel out of the cylinders and put the 50/50 mix back in. I have to admit as of now the cylinder walls are not shiny, I can see soot and on the walls from where the pistons were. But i’ll let it soak and clean them. Do you think I could use Skotch-brite on the cylinders or is that a bad idea? I use it on small engines a lot. I’m not very computer smart so my dads going to help me post photos later today.

[Sugar Bear]

Yes to a medium grade Scotch Brite. Put the piston low in the bore, place painters tape in a way that prevents debris from falling alongside the piston. Scuff on a 45 degree angle and then on an opposite 45 degree angle to mimic a cross hatch or X shaped pattern.

I'd also rock the pistons side-to-side with the ATF acetone mix in place to work it into the rings/piston grooves. The goal is to only remove the glaze on the cylinder wall to help the rings scuff and reseat. Stop as soon as the surface dulls.

I'd leave the two good cylinders alone.

Good luck!!!

[Todd Miller]

^^This is great advice^^

I personally don't protect the area around the pistons. Instead what I do is bring the pistons to the top, and then back down again, and any debris is left sitting up high on the cylinder walls, and can be wiped away. I follow that with spraying down the cylinder walls with carb cleaner, and then blasting them out with compressed air, by sticking the nozzle of the air gun into the cylinder, and putting a rag over the top (So I don't frag myself in the face). I keep bringing the pistons up and back down, until it's clean looking, and then I give them a spray of TriFlow to prevent flash rust.

Regarding run-away diesels, and I've had my share of them in customer cars. They can be shut down immediately by blasting down the air intake with a fire extinguisher. So keep the air intake ducting off your intake manifold, and a fire extinguisher handy. If she begins to race, you can stuff a rag and your hand over the intake opening. If that doesn't shut the engine down, give it a hit with the extinguisher.

[C4rest]

Here are some pictures of what the engine looked like after I pulled the head. Right now I have the 50/50 mix in the cylinders and i’m keeping it topped off until I drain and clean them!


https://share.getcloudapp.com/Qwu82bzG
https://share.getcloudapp.com/rRugW0KP
https://share.getcloudapp.com/JrupnqY1
https://share.getcloudapp.com/yAuJ0ZRy
https://share.getcloudapp.com/NQuW7Km4
https://share.getcloudapp.com/z8uG14Wd

[Tony H]

Years ago I bought a stationary generator that had been outside unused for at least 10 years. It was locked and, in my ignorance, I kept bumping it with the starter until it turned over. I used it for years with no issues. That's probably the exception though.