Originally Posted by Jeremy5848

Since I have one of each --

The W124 with the 603 turbo engine is a nice car, produced only as a 1987 model year, although actually sold from 1986 until they ran out of them in 1988. The alloy head can crack if the engine is significantly overheated (run out of coolant and "try to make it home"). Don't. The later versions of the head pretty much take care of that problem. All can be good engines that last a long time if you just keep the cooling system in good repair. The bad rep is probably not deserved. Many forum members have excellent examples.

The 1986 300SDL (W126) also used the 603 engine, same as the '87 300D (W124).

In the early-to-mid 90s the S-class (140) used a version of the 603 that was punched out to 3.5 liters. This is the engine known as "the rod bender." Although there are stronger rods available from the factory, the chances at this late date of getting a set installed for free are slim to nil. Most folks recommend avoiding this model unless you can get it dirt cheap. In that case, enjoy the otherwise fine car until the engine self-destructs and then either throw it away or transplant a 603 engine from an '86 or '87.

Later W124s (1990-93) are available with only one diesel engine, the 602, confusingly badged "300D 2.5," they have a 5-cylinder 2500cc turbocharged diesel. This engine does not have the head problems that early 603s had. Good performance and excellent fuel economy. Passenger air bag moves the glove box to the center console.

The 1995 E300D (W124) with the 606 NA engine is a "hybrid," newer engine in older chassis. The 606 is a six-cylinder naturally aspirated double-overhead camshaft engine. It loves to spin and makes a fair amount of power if you let it wind up. If you try to lug it around in higher gears like you can with a turbodiesel you will be disappointed. Only known significant problem is a tendency for glow plugs to stick and, when the owner/mechanic loses patience, the glow plug snaps off in the head. I have not had this problem.

The 1996 E300D (w210) is an entirely new chassis with the same 606NA engine. Mercedes designed the 210 to have a stiffer suspension than the 124. It's immediately noticeable and you will have to decide whether you like it. The 210 chassis can have rust problems, especially in the area of the front spring perches in areas that have salt on the roads in winter. The '96 retains the reliable 722.4 4-speed mechanical/vacuum automatic transmission that goes all the way back to the 1985 300D-T (W123) models. In 1997, the new electronic 5-speed transmission was introduced. Had a few teething problems.

For 1998 and 1999 the transmission problems were overcome plus the 606 engine was turbocharged. These later models are also more electronic and harder to self-diagnose without specialized equipment but are good performers with good fuel economy. Many satisfied owners.

Recommended: low miles, pre-inspection, complete service records from PO. Otherwise you're shooting craps.

Jeremy

Originally Posted by Oldwolf

I've had my 93 "300D 2.5 Turbo" for about 10 months now and have put about 15k miles on it.

I've only had to do routine maintenance on it so far but the learning curve was steep for me because I had owned domestic gassers for a long time.

I'm getting 30mpg this winter and about 33mpg (averages) due to the winter blend of diesel fuel (probably).

I'm happy with mine. It sure cruises nice on the highway, I use it as my daily drive and commute about 75 miles per day.

I was worried about winter engine starting but am finding it still starts after 2 or 3 rotations regardless of temperature.

These are pretty neat cars.