Buyer's guide? - PeachParts Mercedes-Benz Forum

meek · #1 10-22-2011, 05:40 PM

In the market for a couple of W123 diesels. Thinking a TD and a CD. What am I to look out for? What are easy fixes vs $$$$$ fixes? Thanks.

FWIW usually I am a "Search King", just don't have the time right now. Thanks again for your understanding.

junqueyardjim · #2 10-22-2011, 07:21 PM

The biggest problem is finding a rust free car. The rust worm loves the W123 in any color or form and will totally devour it. The older W123's, unless it has the simple heater controls of the 240D, have a very complicated and hard to maintain heater/AC control system. AC can cost you big bucks, and R134 is really not a good switchover freon. It is hard to do or find, but there are a few premium cars running with R12. The wagons are great if you want a wagon, but again the rear hydraulic suspension has given many owners fits. The OM 617 is a real horse, but can die in a minute if the chain lets go, or the vacuum pump poops, or flywheel damper comes loose and eats the front of the crank. They are really great cars, but like everything else, they have their soft spots. So try to find a car without rust, (no rust repaired), pull the carpets and padding out of the car and check the floors. They rust from the outside from salt and rust from the inside from AC water or leaking sunroofs. Try to get the car on a lift and critically look at the underside. Push on suspect spots with your hand or the back of a hammer head. Don't beat on it if you don't own it, but check it out. Take it for a couple mile run and park it and see how much oil it is leaking - not all oil leaks are big dollar items, but they all are big pain in the butt items. Try to find a car that has some records, who has an owner who will really tell you about the car. If he says he gets a steady 32mpg from a 300D with or without the turbo, run because he is lying to you. Mostly, the turbo engine is loved by all of us who have them. They are strong, easy to live with and pretty good on fuel. Largely the guys on the forum do not burn WVO, lots of controversy there. The coupe, hardtop, is the darling of the group, but it has a high number of body parts which are not shared with the other cars and usually commands a premium price. Exceptional good looks are always in demand. The 240D four cylinder is the same car, can be found with the four speed manual and is a delight but has only 85 hp. Mostly, the 300D's are automatic, kind of sludgey but pretty serviceable - but they are getting old. There are a few 4 speed and 5 speed manual around, but scarce as hen's teeth. I have one, as do a number of members by making one using the four speed parts in total out of a junkyard 240D. It is a lot of work, but very straight forward and makes for a delightful car.

Skippy · #3 10-22-2011, 08:45 PM

There are parts of the country where rust isn't an issue. The OP may be in one of those.

The front ends generally need a rebuild somewhere between 250,000 and 300,000 miles. If it's already been done expect to pay more.

If a car has ever been run on vegetable oil, assume it was done wrong and figure on at least an injector pump and set of injectors. Improper veg has been known to total engines, but this is less common.

The 240D actually had 62 hp in the early models and 67 in the later ones. Still, with a manual transmission they are pretty fun to drive.

I have one of the manual conversions mentioned above. It's a 300D (with turbo) with the four speed manual out of my old 240D. It's pretty enjoyable to drive and much better than it was with the slushbucket.

People have had relatively good luck buying non-runners for pennies. Common problems that make one of these cars not run are a malfunctioning glow plug system, plugged fuel filters, and valves so far out of adjustment as to bleed off compression and prevent starting. All of these are relatively easy fixes, but some people don't know that.