Well I have been reading the posts for quite a while now, and I think I have decided on an early eighties diesel. I have always admired mercedes, but know nothing about diesel engines. I looked at a 1984 300td yesterday which was junk. It needed way too much work than I am willing to put into it. Next week I am going to look at a 1981 300sd. 140k miles. Owner is 2nd owner who bought 3 years ago for 7k in his words to prepare for y2k. He had a line on some bio-diesel fuel from Maui, and was preparing for a lack of diesel fuel. He said he bought a couple of barrels of this stuff made from used cooking oil. He says the ac has just gone out, but other than that the car needs nothing. He is selling because he does not need the car anymore. He also has stated car gets 30 mpg. He is asking 2900/obo. What is the most important and costly things to look for? Did he damage the engine from using this fuel? How could I tell? My diy talents have thus far been limited to routine maintenece. brakes, filters, oil changes. Well, I will let you all know how the diesel market is over here in Hawaii, and thanks for all the information in the posts I have and will continue to read. Aloha

A/C just went out Sure was a neccessity for me when I've been in Hawaii. Can be a loose wire or $1000+. The 126 chassis 300SD A/C is an interesting German concoction of electrical and vacuum, and probably not the system to try your DIY skills on as an initial introduction to the car. Negotiate price based on this. It coud be only one bad vacuum actuator, but it's always the one that you have to (should) remove the dash to get to. Evaporator replacement? Don't even go there. They are GREAT cars, but try to get a handle on exactly what the A/C problem is before buying. Hint: all P.O.'s claim "it just needs a charge". Yeah...sure... then why do they never charge it so it works before trying to sell it?

Methanol residue(or some kind of residue?) in biodiesel can be a problem for hoses and IP seals, but I think that would have shown up by now (3yrs.?)

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)

Thanks for the reply. Yeah AC would be nice but wouldn't rule out the car because of it. Good way to get the price lower I guess. My main concern is rust from being here in Hawaii, but owner says no visible rust. I'll let you know how it goes next week. Have read most of the posts on these early to mid 80's diesels and they sound like good, big, dependable cars. I am 6 foot seven and need the room plus a new baby just arrived. Without the AC I'm thinking about 1500-2000 so we'll see what happens. Aloha

Sounds like you know your homework. Here's an asset: http://www.mbz.org/info/articles/buying/126/

__________________
The Golden Rule

1984 300SD (bought new, sold it in 1988, bought it back 13 yrs. later)