15th Feb 2005, 21:24
The W126 body, or the S-Class we are talking about is more or less an extension, if you will, of the '70's Mercedes. It has exactly the same underpinnings as the previous S-Class (W116).
As far as the cylinder heads go. They will only crack if the car was overheated. Even once. I have 286K miles on my 300SDL right now. Original head. So rest assured, all is well in good for the future of a watchful eye.
12th Apr 2005, 04:14
From what I've read and had explained to me by certified mechanics, the washing of these motors with these heads is a big no no if they are hot, (as in up to operating temp). My main authority, who has been to and thru all major auto plants in Europe, says that the Mercedes designers of these cast iron block/aluminum head combo went to extensive pains to eliminate the linear expansion difference of these two metals.
13th Oct 2005, 14:16
Okay, 2 years and 40k miles later, the glow has worn off the 300SDL a little, but not too much. A water pump, tie rod, and a few other things replaced, nothing major. Definite signs in trim, paint, leather say "I'm 18 years old". What a great car. However, my 115-chassis 240D has moved back to preferred status because of funky headlights, smoke-belching spunk, and 4-speed manual (I love you Sputnik -- keep up the good work).
4th Nov 2008, 14:24
I have a 1986 300SDL with 302,000 miles on it! I love this car. It still rides better and looks better than anything newer on the road. I have had to put some money into it by redoing the front suspension and center bearing, but for a car with that much mileage on the original engine who can gripe?
I had a 1981 300SD before this car and the difference between the models is amazing. The 300SD felt like an agricultural implement with the 5 cylinder engine. The 300SDL with the 6 cylinder gets better mpg, is faster and is a bigger car. It feels like a limo in the rear seats.