thinking about drinking the cool aid - PeachParts Mercedes-Benz Forum

DavidF · #1 06-08-2013, 06:45 AM

I'm seriously pondering joining the diesel club. I have a 1963 220s and really enjoy working on it. Everything about diesel appeals to me. But how realistic is it, especially if I intend to start on the very low end.

I'm looking at a 1985 300TDT with 186k miles for $1,200. What should I look for when I inspect this car? What are the common failures that a shade tree (literally my garage) mechanic can fix? What are the signs that the problem is too big?

Thanks for sharing your considerable experience.
David

vtmbz · #2 06-08-2013, 07:14 AM

Rust is always the deal breaker in Vermont. You have to spend money to keep a 27 year old car in good working condition, and if the body is bad, its money down the drain.

Skippy · #3 06-08-2013, 07:17 AM

The '85 model will have the pencil style glow plugs. My '83 with the same system has started down to 14 degrees or so almost as if it were 80 degrees out. It's a Texas car and doesn't even have a block heater. I used to have a '77 with the much less effective loop style plugs. It was tricky, but not impossible, to start once it got into the 20's if not plugged in. That one was an Iowa car and if plugged in a couple hours before starting would start easily in the coldest weather I tried it, also the teens.

If they use a lot of salt in your area, rust will likely be a problem. I would also tend to stay away from any car that has been run on straight or waste vegetable oil. Veggie conversions aren't inherently bad if done right, but most of the people who do them manage to muck it up in one way or another. Odometer failure is endemic in these cars. All mileage claims are suspect unless backed up by some sort of documentation. That said, condition trumps mileage every time.

When you go to evaluate the car, specify that you want to start it from cold. If it has trouble, most likely it's a glow plug failure, which is usually a relatively easy fix, but it should help you bargain for a lower price. If the car starts easily, runs well with decent power, drives well, and the transmission functions well, it probably doesn't have any problem other than maybe rust that you can't handle.

Since you're looking at a wagon, there is also the self leveling suspension. I haven't worked on one. I understand they can be slightly complicated, but not insurmountably so.

daw_two · #4 06-08-2013, 08:01 AM

Quote:

Originally Posted by DavidF

I'm looking at a 1985 300TDT with 186k miles for $1,200. What should I look for when I inspect this car? What are the common failures that a shade tree (literally my garage) mechanic can fix? What are the signs that the problem is too big?

Thanks for sharing your considerable experience.
David

Hi David --- good name.

Is it a 4 door sedan or a wagon? You said 300TDT, but what is really on the trunk badge? Rust, Rust, and Rust is probably your worse enemy up there. Look under the floor mats. Look in the trunk. Look up under the car; check the hood hinge pockets. If you really want a rust free care, look for one from the South. Oh, yeah, I just happen to have one sitting on a trailer with a ceased engine.

If you go to inspect the car, and the seller will let you take pics, post some up and we can give you a better opinion of the car.

vtmbz · #5 06-08-2013, 10:53 AM

The car is advertised as needing floor pans if its the same one I saw. Be diligent in searching for other holes. ONe rust hole is lonely. THe undercoating does a very good job of hiding rust through.

DavidF · #6 06-08-2013, 01:00 PM

Might well be the same one, a blue wagon in Montpelier. I kind of like body work and floor pans are pretty straight forward, I would think. Is it body rust that is a warning or frame rust?

Alastair · #7 06-08-2013, 01:48 PM

Mercedes of that age hide rust incredibly well.....

IF the floorpans are rotted out--you can be sure there'll be much more rust in more stress-loaded areas.

Places to check would be the inner rear wheel-arches, forward of the wheel--where they attach to the sill under the doors and around the rear sub-frame--there's a double-skin there forming a box-rail This is all Structural areas supporting rear spring-perch and subframe Lot of work to repair properly.

Area immediately rear of the front wheels can rot by the jacking-points--worth having a good grope around those places...

Another very prone point would be areas in engine-bay where the bonnet hinge mech sits and immediately under this area up to the bulkead.

Check same on both sides--Battery-tray and especially Under it. Horrible to repair properly if really bad.
Wings and doors easy to replace--The main structure 'tub' of the car isnt so easy to repair right.

There was a thread somewhere in the Bodywork section showing some hideous rusting, and the places the rust happens--worth searching that out and making a few notes on what to check on a car viewing!

Jeremy5848 · #8 06-08-2013, 02:23 PM

1985 was the last year the W123 was imported into the USA. Thus, it has all of the changes/improvements/upgrades made during the life of the model. There are a few things that are unique to this year/model; this is not necessarily a problem (it wasn't for me when I owned one) but you do need to be aware, especially when junkyard parts hunting. Try to avoid the California version with the trap catalyst (you probably don't see them often in VT but you might be tempted to buy a rust-free example and have it shipped to you).

Jeremy

Equestrian · #9 06-08-2013, 09:15 PM

I had an 83 30D with a 617 turbo. Great car but it was a Michigan transplant so total rust bucket check everywhere its bad on northern cars. Join the diesel dark side you won't want to go back i drove mine abusively ie: teenager in a rental car throttle at idle or floor and still returned at least 24 mpg. Completely shot with rust and beat to hell and it still sold for $700. I kinda miss working on that old tractor dirt simple mechanically speaking.

Skippy · #10 06-09-2013, 06:03 AM

Needs floorpans? That would be a parts car in my part of the country.