MB diesel newbie needs some purchase help
 

How's it going all. I'm a newbie to Mercedes, but not to diesels. I currently own a '91 f350 7.3 IDI. There's a '90 300D w/ 2.5 turbo for sale near me and I'm interested in it. It has 215K on it, and the body is pretty good. I've taken it for a ride, and it rides nice, but at idle it vibrates like hell. It idles at 600 rpm, and it's real rough. But once it's up to 1000 rpm it smooths out nice. The guy is asking 3500 for it, which I think is a little high. Is the vibrating and rough idle ared flag, or something common, or easy fix. One more thing--how expensive is it for parts for these? I appreciate the help. Thanks.

Vibration in a 300D
 

I am thinking that the problem is most likely due to a collapsed engine mount.
The one most apt to collapse is the one on the driver's side, in the area under the small plastic (primary) fuel filter. They collapse because fuel gets on them and disintegrates the rubber.

This will also cause the fan to whack part of the fan shroud, most likely.

thanks for the reply--how are the 1990 model engines? From what I've been reading, '90 wasn't one of the better years. I'm thinking maybe I should let this one pass. What are some of the better year diesels?

IMHO... 77-85 W123 ;)

240D's are uber slow... but well worth the wait... I love every waking minute of it.
a 4 speed it a blast.... until the slave cylinder went...
$242.93 later its a blast again!


sorry
im excited.
i just got it back today :P

i don't know where you're from
but i just got back from Tampa.
there are two of them in the mid $2K range that looked pretty decent. and i just stumbled on them. craigslist has tons scattered over the south...
check em out.


Matt

'90 was a fine year. The 602 engine never had much for problems, the early turbos were in '87, had some head and head-gasket troubles, but none mentioned in the FSM for the '90-up 602.

There can be some low-boost related issues from sensors and vacuum lines in the '90-'93 300D 2.5Turbo, but otherwise excellent.

Look for the buyer's guide for the 124 chassis, there are A/C & Heat issues to be careful of, and suspension slop can "nickle and dime" you pretty bad.

I'm just afraid of getting involved with another money pit. I've been reading on the signs of potential problems, and this car has a few of them. Maybe if he wants to let it go for 2k or less I'll get it. That low rpm vibration and roughness is definitly a putoff.

The 1990 300D engine is actually one of MB's better efforts... the one to stay away from is the 1990 350 engine. The 3.5 liter has perhaps the worst reputation out of all MB diesels in the last 30 years, arguably, but the 5 cylinder in a 300D from that period should be every bit as reliable as a 300SDL from 86-87.

I don't know of any particular problems with the 1990 model 2.5 engine. It has LOTS more power and better fuel economy than the 1985. I have one of each.
The vibration is probably the engine mount, but whatever it is, it is not typical of any MB engine in good shape. This may or may not be a good car for you. It is 18 years old, after all.

The 1985 is easier to work on, but the 2.5 turbo does not require valve adjustment every 10K miles or so. My 1990 leaks oil more than the 1985, but that is atypical as well.


Good luck in any case.

thanks for all the info--I'll have to check it out a little better. We'll see...