Looking for a diesel sedan - PeachParts Mercedes-Benz Forum

74baja · #1 01-04-2009, 08:24 PM

Hi all,
We recently started looking for an older mercedes diesel sedan, mostly for the reliability and fuel economy. I am wondering which engines/models are the best for reliability and fuel economy. I think I heard that the 5 cylinders were the best, but I don't really know about he 6 cylinders. I have seen some 300d s , some with 5 and some with 6. What are the year ranges for each model and engine? I am looking for a pretty big sedan.
Thanks,
Jack

daw_two · #2 01-04-2009, 08:34 PM

Jack,

Welcome to the Forum and glad you found us. This website should help:
http://home.hiwaay.net/~gbf/mbmodels.html

Most of the guys in the diesel discussion forum have either a w123, w124, w126, or 2 of them, or all of them.

Visit often, try the search function (Google here), read a lot, and ask questions.

Enjoy the adventure!!

74baja · #3 01-04-2009, 08:41 PM

so, if I was looking for a turbodiesel 5 cylinder sedan, the only years would be 82-85 and 90-93? But I'm still not sure if the 5 cylinder really is better than the 6 cylinder

eagle-co94 · #4 01-04-2009, 09:18 PM

If you click on User CP above and then click on Edit your details on the left you can enter where you are from. That'll help local people that may be able to help you see where you're from.

I think you should take a close look at some models and talk to their owners to get a good idea of what you're looking at. If there's a get together happening near you that would be best as you could see lots of different models with different options all at once.

Ether · #5 01-04-2009, 09:18 PM

The 617 3.0 liter 5 cylinder turbo diesel was also available from 78 to 80 in the W116 300SD. This is a larger car than the W123 and just a tad smaller than the W126. A 5 cylinder was also in the 90-93 W124 300D as a 2.5 liter.

The 116's are known to have rust issues but if you can find a nice southern example that's been properly maintained they are a joy to drive.

The later 6 cylinder diesel engines are more powerful and smoother running but I'm not sure if they match the 617's legendary reliability.

mobetta · #6 01-04-2009, 09:30 PM

if you want big, you want a 126, ( 300sd, 300sdl)not a 123(300d).
both series, in the early 80s, shared in the legendary 617 5 cylinder engine that you are prolly referring to.

Oracle12345 · #7 01-04-2009, 10:00 PM

I found my 77 in local craigslist ad and Im not disappointed at all. really good body for a north eastern car. Spent a lot of time in florida

quickster · #8 01-05-2009, 07:32 AM

where in Jersey are you? I saw a '90 300D on Craiglist not long ago, in Montclair I think. You won't be disappointed with the 124.

#9 01-05-2009, 07:34 AM

You really can't go wrong with the 3.0L inline 5, a few things find one with a good service history or be prepared to spend a few weeks doing deferred maintinence. And good luck.

LUVMBDiesels · #10 01-05-2009, 12:05 PM

I have had both a 1981 300SD (W126 with the five cylinder engine) and a 1986 300SDL (W126 with the longer wheelbase and the six cylinder engine) I have to admit that while I liked my 300SD I love the SDL. The six cylinder OM603 engine is much smoother and more powerful than the five cylinder OM617 engine. The SDL is a bigger car with more room in the back seat area (think baby limo), yet returns better fuel economy. Other differences are that the SDL has a driver's side air bag and antilock brakes. I would not go back to the older car.

Look on Craigslist for the best deals. Also look in this forum as members sell cars all the time. What you want is the best car you can afford.

Watch out for rust where the plastic cladding meets the body on the W126 cars. They like to rust on the door panels and especially the rear quarter panels. Check out the climate controls and the windows as these can be problem areas.

All these things are pretty easy to fix but try to get the best one you can as there is nothing as expensive as a cheap Mercedes!

I had originally picked the 300SD as I had heard bad things about the later engine. The cast iron OM617 is pretty much a solid piece of equipment, but there is more maintenance involved doing things like valve adjustments. The aluminum head OM603 has a tendency to crack if overheated so when you take a test drive in a later car check the temperature gauge. It should not go higher than 90 degrees. You can also search this site for tips on how to see if the head is cracked.

Either engine can go 500000 miles so don't be alarmed at higher mileages. My SDL just turned 300,000 and has had no engine related issues.

Whatever you pick welcome to the lifestyle! Be sure to join the Mercedes Benz Club of America (MBCA.org) and attend local chapter meetings. There you will meet people who can answer your questions and give great advice.

GroßeH · #11 03-02-2009, 06:30 PM

Bump for more responses! I like what i'm reading regarding what you all are driving and what you think.

diametricalbenz · #12 03-02-2009, 09:58 PM

If fuel economy is one of your criteria, throw away EVERYTHING you know on EBAY and CRAIGSLIST. None get 40mpg unless you drive 35mph or specifically have a 190D 2.2 4cyl.

Unless you find a 240D (4 speed manual) or a 190D 2.2 or one of the post 1990 2.5L cars you can't obtain more than 30mpg which pretty much any current domestic or foreign car of the same size or often larger can exceed with more amenities.

Sloppyjoec · #13 03-02-2009, 09:58 PM

I have a 75 240d with a n/a (no turbo) Four cylinder engine, it can go on surface streets no problem and on the expressway about 65-70 ish, i have a <25 mile trip to work and so it is no problem, but an hour long trip would get old every day my car is about as fast as a school bus. Also i am from mid michigan and in the winter, starting the thinig in the cold mornings is... diffucult.

Also fuel ecomedety, abou 23 mpg, hard to nail down exactly odometer is not corect.

strelnik · #14 03-02-2009, 10:29 PM

Quote:

Originally Posted by Sloppyjoec

I have a 75 240d with a n/a (no turbo) Four cylinder engine, it can go on surface streets no problem and on the expressway about 65-70 ish, i have a <25 mile trip to work and so it is no problem, but an hour long trip would get old every day my car is about as fast as a school bus. Also i am from mid michigan and in the winter, starting the thinig in the cold mornings is... diffucult.

Also fuel economy, about 23 mpg, hard to nail down exactly odometer is not corect.

I am surprised at your low mpg on a 123 240D. Mine's higher with an AT. and it starts with two glow plug cycles at 5 below with no diesel block pre-heat tho I do use one sometimes when a cord is available.

But I just bought a W115 with 615 engine (220D) and a manual. Partly to play with partly to clean up and drive.

daw_two · #15 03-02-2009, 10:42 PM

Quote:

Originally Posted by diametricalbenz

If fuel economy is one of your criteria, throw away EVERYTHING you know on EBAY and CRAIGSLIST. None get 40mpg unless you drive 35mph or specifically have a 190D 2.2 4cyl.

Unless you find a 240D (4 speed manual) or a 190D 2.2 or one of the post 1990 2.5L cars you can't obtain more than 30mpg which pretty much any current domestic or foreign car of the same size or often larger can exceed with more amenities.

Did you say you were looking for a 240D, 4 speed manual?