As new as you can afford... full service record is best... bring a buddy who
knows alot about MB or take it to a MB tech to have it inspected...
And test drive it well... so you get an idea what is normal and what is not.
On Fri, 27 Aug 2004 16:31:42 -0500, "L A Davenport"
The 5cyl in mid 80's and older diesels has a cast iron block and
head, you can't kill them. The later 6 cyl's (3.0 L) had aluminum
heads, that could warp or crack if overheated. The 3.5L 6's had
trouble with the cylinders...not sure of it is the correct term,
warping, changing from round to oval shape.
I've owned a 77 240D, 80 300SD, 84 300SD and
(currently) an 87 300TD, so I've had experience with 4, 5 and 6-cylinder
diesels. All are excellent, but I feel the best engine overall is the
6-cylinder in the 86 and 87 models. It is the smoothest, most powerful
and gets fuel economy comparable or better than the older diesels. Yes,
if overheated the head can warp. Mine has over 220K and I've never had
the head replaced. I had a new radiator installed two years ago. If you're
careful and keep the cooling system in good condition head warpage should
not be a major issue.
I would definitely stay away from the 3.5 liter 6-cylinder diesel found in
early 90's cars. They had a disasterous record.
The only diesel i have owned is my current 86 300SDL with the inline
6, which gets 22city/25 highway, compared to (told from owners) the
same generation 300SD's with the inline 5 with gets 28city/32 highway.
They get almost 600 miles to a tank where i am on empty just over 400
and i have a bigger tank.
I was a hair off, but not much. Original EPA ratings were 26city, 30
highway (for a 300SD w126). Any idea why they stopped production of
the w126 diesel after 87 until the 350SD and SDL came out? If the body
style was still popular and diesels were still being used in other
models and again in these, why the gap?
The gap was likely the falloff in sales of diesels in general because of the
in fuel prices in the late 80's, not any inherent flaw in the diesel engine
Among the most talked-about and highly sought after diesels are the 86/87
and the 87 300 TD-T. Low mileage specimens in excellent condition are
sold on the used market.
Regarding fuel economy, I maintained my diesels in excellent condition, used
primarily Mobil 1 oil changed regularly, Red Line Diesel Fuel Catalyst and
regular valve adjustments. My 80 and 84 300SD's got about 25/25 in mixed
and 27/28 MPG highway. The 87 300TD gets 26/27 MPG in mixed driving and
28/30 highway. As I said, I liked all the diesels but given the choice would
the 87 6-cylinder as the best all-around engine. (Just make sure the trap
was replaced under the factory recall - and you get a new exhaust system in
The five cylinder diesel is really the old 4 cylinder 240D with an
additional cylinder grafted on. That was done in the mid 70s to achieve
about 77 HP. In 1978 the internals were strengthened and a turbocharger
added for the first 300SD Turbodiesel (110 - 120 HP). The engine's
technology is old and quite simple, a great engine for a DIY owner.
The engine's maintenance is oil & filter change at 5K miles, valve
adjustment at 15K miles and filters at 30K miles. The engine will be
good for 250K to 300K miles if it is so maintained. These old fives are
all cast iron and very durable machines. Their other advantage is that
lots of them were sold so finding a used engine isn't difficult.
The newer six is a more powerful engine (148 HP) that's also inherently
smoother, being a six rather than a five. It's aluminum head is not as
durable, its cooling system must be well maintained to avoid overheating
that causes cylinder head and or cylinderhead gasket problems.
The internal condition of any diesel will be revealed by a compression
test and I suggest you have one done before, not after, buying one. Its
$$ well spent to know that you have a good car or to avoid an expensive
lesson later on.
My girlfriend has been running her 1984 300d
on Biodiesel for six months. I just picked up a '79 300sd
that I will also be running on B100.
I changed the fuel filters after the first tank, and
that is about all I had to do for the change to
Smells better, runs smoother, smokes almost
not at all. I recommend it!
Plus it keeps the money you spend on fuel,
much closer to home, which I really like.
Are you saying that the same amount of money goes
overseas to buy part of the fertilizer?
Or is your argument a bit disingenuous?
I believe self reliance in energy is a vital component of
national security that is being completely ignored by the
vested interests in power. I feel the need to act as an
individual in a way to bring change in our energy policy
(at least my own personal policy) I am willing to pay more,
for fuel that is not drilled and shipped from places full of those
who would do us harm. If there is some amount of oil in the
fertilizer that is used to grow the soy, that is used to make
the Biodiesel, then it is not a perfect answer, but I think it
is *better* by large magnitudes.
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