[W126 Coupe] OFF TOPIC - 126 CHASSIS DIESELS 300SD VS 350SD

[Mister McGoo]

Rich;

Assuming that you want to stick with the W126 chassis...

Your choices of diesels are:

300SD, 3.0 litre 5 cyl (617.951) 1981 - 1985
300SDL, 3.0 litre 6 cyl (603.961)  1986 & 1987
350SD, 3.5 litre 6 cyl (603.970)  1991
350SDL 3.5 litre 6 cyl (603.970)  1990 & 1991

All of the engines delivered to N. America are turbos.  (In fact, I believe 
that the W126 was not available in diesel version in Germany.  Strange??)

The 5 cyl 300 engine is the workhorse.  Tends to be dirty, oil leaks are 
common.  It will likely run as well on diesel, stove oil or heating oil.  I 
don't know anybody who has tried Macdonald's used deep-fry oil.  Yet.  (The 
non-turbo versions in the W123 would be an ideal candidate to try)

The 6 cyl 300 engine has noticeably more power and runs smoother.  I have 
heard critics say they tend to bend connecting rods but I don't personally 
know of one case.  My experience is with the simiilar engine (603.960) in a 
300D and a 300TD (both W124's).  The station wagon ('87) has abt 400,000Km, 
of which I have put well over 200,000. It just keeps running and running and 
running...

The only one experience I have with the 350 diesel, (which is the same basic 
engine as the 300), was in a W140, not the W126, and at 135,000Km (80,000mi) 
the engine had SERIOUS internal problems.  I have subsequently heard other 
bad experiences with that engine.  But I must emphasize experience with one 
car and a bunch of rumours needs some verification.  Maybe someone else has 
some servicing experience with the 350 diesel.  There are not many around.

Hope that is of some help.

-Bellamy


>From: "RICHARD JAFFE" <RSJAFFE at msn.com>
>Reply-To: Mercedes Coupes Mailing Lists <mbcoupes at mbcoupes.com>
>To: <MBCOUPES at MBCOUPES.COM>
>Subject: [W126 Coupe] OFF TOPIC - 126 CHASSIS DIESELS 300SD VS 350SD
>Date: Sat, 3 Sep 2005 00:15:11 -0400
>
>I'm thinking about getting a diesel as a daily driver. The issue is whether 
>to stick with the 3 ltr 5 cyl turbodiesel (these seem to be pretty bullet 
>proof) or go with the 3.5 ltr 6 cyl turbodiesel (1991 model year). One 
>website mentioned numerous problems with the 3.5 ltr motor that MB did not 
>acknowledge. Anyone have any experience with either of these vehicles?
>
>Rich Jaffe


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