Good morning, I have recently found a w115 Mercedes-Benz 220D that used to belong to my grandfather, unfortunately when he died the car got stored in a garage and my whole family forgot about it. I am very inexperienced but I was thinking about fixing it since it doesn’t seem in bad shape. Have you got any suggestions on what I have to do? Keep in mind that I don’t know anything about anything so don’t be afraid to state the obvious. Thank you very much

Very cool my dude! I'm less familiar with Diesel engines so take this with a grain of salt. But here's the way I'd tackle this. There will be youtube videos for things like this. I believe that's the OM615 engine, so I'd run a search on getting one of those things started up.

A few questions. You say you don't know anything about anything, do you have tools? If not, you may want to consider if you want to learn to wrench, because tools are a really significant investment. So if you haven't wrenched before, you're going to want things like :

- Wrenches - I recommend a longer set and a stubby set, I like the ratcheting type of wrenches for the stubby sets. Harbor freight Icon stuff isnt cheap, but it's excellent. You want two sets because a lot of times you'll need one wrench set to hold and one wrench to turn.
- Sockets - if you're doing engine and suspension work, you'll want a 3/8" set and a 1/2" set. Trust me. Anything will do, you don't need to spend crazy money here
- You'll want breaker bars for each of those sizes. Go cheap on these. Harbor freight has them for i think under 10 or 20 bucks. If your wallet can handle it, get a battery powered impact wrench, it's a game changer.
- You'll at least want a floor jack and jack stands. A decent one runs around 100-200. I have the harbor freight daytona stuff, it works.
- Screwdrivers, and allen wrenches, torx bits. Spark plug socket, A headlamp.
- The last thing I'd say you need for a beginner set is a torque wrench. Depending on what you're doing, I'd recommend the HF digital one. But it's best not to go all the way cheap on these, expect to spend 100 bucks on these. I have two, one that goes from 10 lb ft to 150 lb ft in 3/8" and a 30 lb ft to 250 lb ft one in 1/2". They cost me around 200 apiece, but they're essential.

I'm sure I'm missing a ton of things but that's where I'd start. That said, if you have none of that and you need to get all of it, it'll cost you 500 - 1000 to get started.

Alternatively, find a good independent mechanic to get the car cleaned up and running, I expect the engine won't need a full rebuild, but it probably needs a lot of rubber and gasket replacement.

If you're dead set on DIY - the first thing I'd do with those old W115 is check the chassis for rust, look at the rockers, floorpans, trunk, the corners around the windows and windshield, and basically anywhere else, those things are prone to a little rust. But if the body is clean, its worth a restore. If rust is eating it up, unless you have a ton of body work time or budget I'd bail.

- After you check the body, start going over the engine, squirt some oil into the cylinders and find a video that tells you how to rotate the engine by hand to make sure it turns alright.
- Then get to work refreshing everything. I'd start by emptying all the old fuel from the fuel tank, replace the filters, fuel pump... maybe.
- The next thing I'd do is refresh the ignition system. I think on those engines it's glow plugs and etc, but you'll need to look it up.
- Oil, oil filter, fresh gas, fresh battery, fresh air filters.
- Coolant system flush, ATF fluid change

Then I'd start it up just to make sure it's running, and identify if it's got oil leaks and whatever, or if it's running rough.

Then starts the real work.

Hope this helps.

Sounds like a great project. Definitely worth doing just for the car itself and also because it's a family heirloom!

They're fairly easy to work on I find. Simply but well engineered. Also, please post some photos of it in it's slumber! I'm sure a lot of folks (me included of course) would love to see its revival

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1975 W115 300D