Looking at a ‘78 300D
 

Been wanting an older Mercedes diesel for a while, going to look at this particular car this weekend. Gentlemen says it runs fine, what do I need to look for?? If I get it, I’ll service it immediately, would it take 10-30 or 15W40 oil?? Preferred fuel filter?? Any tips are appreciated!!

Can you take along someone that knows these cars? Is rust an issue in your area? Odometers are not to be trusted.

You are interested in a very old car. It may be in fairly good overall condition or needs a lot of work.

If you do not do your own work. It is almost mandatory to have the car checked out by a professional. Service it immediately can mean much more than change the oil. Just to make it sound and safe to drive.

Many sellers will not tell the truth. It is up to the buyer to find it out hopefully before purchasing. Too many buyers wear rose colored glasses.

Rust is not a big issue here in the SE, and I’m fairly mechanically-inclined, I’m going to look it over and drive it, and make my mind up. Good price on the car too. Kinda “smell a rat”, but I’ll thoroughly examine the car

It's cheaper to buy a nice benz than to buy a cheaper one...
Body work is very expensive so it is best to avoid cars with issues in this area.

Other than that if you decide to buy:
- 15w40 diesel oil,
- Mann oil filter,
- new air filter,
- new ATF and filter + gasket,
- coolant replacement with Zerex,
- valve adjustment,
- check all vacuum lines,
- lubricate throttle linkage,
- adjust transmission and throttle linkage,
- disconnect fuel hoses and do diesel purge.

If your power steering is leaking, which is very likely, add Lucas PS Stop Leak and PS filter to the list.

That's for a good start :) then you can drive it and I'm sure you will notice what to do next.

When you finish doing all that, Change the brake fluid and replace the rubber brake lines. they are likely ready to fail or already there...

U sure you wanna get a pre 1980 non turbo? The market has almost completely dropped out for NA 300d's so reselling will be an issue but if that doesn't matter to you then go for it. There's also just a few other querks that were ironed out over the years. And just the face that it's not a turbo frustrates me, I have a NA model as well and honestly, I regret it.

But anyways as for your questions, the motor is "supposed to' take 15w-50 I believe I just try to get somewhere near that. Fuel filters, I like a anything with a German name, I like Mann filter the best. And might as well do the diesel purge while ur at it.

The biggest thing would be to update the glow plugs to pencil and rewire. This will be a must on your car.

South east you probably can live with the older style glow plugs. The natural aspired 300ds are in low demand. So the price you think is cheap may not mean much. I do not drive any of the 123 diesel cars up here in the winter in eastern Canada. So I have no issue with the older glow plug set up.

Most want the turbo versions starting in 1981 simply because they are more powerful and get better fuel millage. They also have a lower rear end ratio so highway rpms are less.

I own a 1977 version of the 300d as well as others. The best example of the ones I have oddly enough was the cheapest. It also is the one most likely to have the original millage on the odometer.

Agree on the drivability of the NA engines. I had a Euro 78 300D for years, even with a newly rebuilt engine, it was a slug. Best feature was its Euro headlights. When I sold it, replaced with an 81 300SD. 1st few times I drove the turbo engine car, realized I had gotten into a habit of just floorboarding throttle pedal when light turned green. If you do that, the NA engine cars drive almost normal in city driving. :)

Check the battery tray, hood hinge pockets, Jack points, spare tire well, floors, and rear window for areas of rust. I would recommend a diesel rated 20w-50 oil and Mann fuel & oil filters as well.

WELCOME NEWBIE !
 

These are good cars, as mentioned the NA ones are not quick but are fine for daily driver use .

I have the putt -putt 4 cylinder 240D sedan, it's pokey but I love the darn thing .

! BEWARE ! a cheap Mercedes will always be the single most expen$ive car you'll ever own .

If it takes more than two revolutions of the engine to start, don't pay over $900 for it .

If you like to tinker these are fantastic cars, otherwise, buy a newer Asian car .

The 77 300d I bought 2 years ago is my DD, and spends most of the time sitting at a train station. It's a great station car, great heat, starts really well with the block heater, otherwise 2 glow plug cycles and good to go. It's a slug but the body is in decent shape, I don't care that the AC compressor is lying in the barn, all the windows power up and down just fine.
I figure for the price I paid, it owes me nothing, and basic maintainable until some NLA part strikes me down. Certainly not worth spending any cosmetic coin on.

My 77 300d originally belonged to Ann Murray the singer. I should really try to sell it to possibly one of her fans before they all die out or I do.

Clear coat is shot though so needs a repaint. Basically still sound car though.

I found the 300na to be a fine driver with the automatic. They are more fun with a stick though.

a 240 stick is engaging to drive, with an auto the 240 is a slug.

My 77 does not have a clear coat, some compound and buff in spots says it's gonna shine up really nice...but do I want a shiney *hit brown car, or a flat weathered *urd?
I have yet to decide....

Where 77 300ds single stage paint? I have noticed the breakdown of the clear on that 77 seems different.

Could it have an original single stage paint that someone sprayed a clear coat on? At some time? I do not feel the car was actually ever repainted as such. I have never heard of that before but I suspect it might be possible.