I'm the proud owner of an '86 SDL. Great car. I hear so many opinion about the cars. I know that the SDL is longer than the SD. I know that the SDL is a 6 cyl. and the SD's are 5 cyl. What is the pros and cons of each peformance wise and repair wise? What are the nags of the SDL and SD's? I've just found an '84 300 SD for sale with service records of over 10 years, about $15,000.00 worth. The guy is asking $4000.00. I've driven it and it runs great. the interior seats are all new. You look under the hood and all the parts that are attatched look new, hoses etc. Is this asking to much? Has about 256k. I'm keeping the 300 SDL, which is an awesome car. I'm trying to decide if i want to add the 300 SD to my collection. I just want to know more about it.

Tom,

That SD sounds like a steal to me.

But you are the potential buyer. What is it worth to you?

P E H

Tom,

In short:

The 300SDL is a great car, plenty of room, smooth quiet engine and plenty of power. Electricals are the same as other W126 cars so read reliable. The OM603 engine in the SDL is very robust, not quite so as the OM617 5-cylinder in the SD however. It pretty much all boils down to which car you like driving better. I will say that from experience, the 5-cylinder has less trouble with oil consumption and cylinder head problems because it is all cast iron, rather than aluminum and iron. That SD you speak of does indeed sound like a steal and at 256K has a lot more life left in it if kept maintained. Watch the tranny however, because they rarely last as long as the engines but that applies to other diesels as well. My '83 300SD rolled 263K the other day on the way back from Cleveland and still lights up in negative temperatures without being plugged in. Doesn't use any oil between 3K changes with Agip 10W-40 dino oil. This week she's receiving a transmission fluid and filter change (exactly at the 30K interval now).

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Regards,
Aaron

Hmm..

How about an SDL with an OM617..
It's not that much more heavy than an SD..

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One more Radar Lover gone...
1982 VW Caddy diesel 406K 1.9L AAZ
1994 E320 195K

tom,
I just got a 300 SDL, and I have a 78 300d. The motor on my 300d is the same as in an SD, except for the turbo. In regards to your question, the SDL motor is more complicated, both to work on, and from an engineering sense.
I think the motor guts are fairly similar, excepting that the SDL has another cylinder, but the injection pump on the SDL is more complicated, since it has an idle speed control which runs off vacuum and the tach somehow. I don't think the SD has anything like this - it is dumber, but that also means there is less to go wrong.
The biggest thing that I can see after 2 weeks with the SDL is that to do just about anything it looks like I am going to have to remove the intake manifold. I was going to change the glow plugs and search for the source of an oil leak near the IP this weekend, but called it off on account of the manifold being in the way. On the SD, the manifold comes in right by the exhaust, so you can goof around with glow plugs and such without getting so much stuff out of the way.
On the SD you will have to take the valve cover off occasionally, since there are not hydraulic lifters on the 617 engine - you are supposed to adjust the valves every 15,000 miles.

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andy t
'78 300d
'95 volvo 850, wagon
'86 300sdl - engine out, maybe I'll have it rolling by June

whole bunch o' bicycles

Tom,
Being an owner of each, both are great cars. The SD is a little more primitive. The 617 is probably the most robust, forgiving engine ever made. It is not the most efficient or cleanest. My SDL generally gets 3-4 MPG better than the SD with more power. You will have to deal with a little more noise (mostly at idle) and valve adjustments ever 15K. The air cleaner bracket is a little under designed. Road noise is a little more, but I think it has to do more with body insulation rather than engine noise. The W126.120 vice W126.125 has a little fewer refinements. But having said that, a well maintain SD with a good body, good interior, and a well maintain engine is a steal at that price (my daughter would have to approve of the color though!).

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D. Blake
86 300SDL 340K (for sale)
83 300SD 205K (gone)
06 Chevy K3500 LBZ CCLB 50K
94 Chevy K2500 6.5L TD 250K (gone)

Thanks, guys. Are the suspension systems simular on these two vehicles? What is the average cost of repairing suspensions, brakes, rotars and shocks on these two at a local MB shop?

Tom, based on personal experience if by 'MB shop" you mean a dealer I suggest you find a good independent repair guy that has a lot of diesel experience (like a fleet guy) and use the MB dealer only for making a punch list of things that need doing, or things the indy can't get squared away. Doing that has saved me a LOT of money! I drive about 25k per year for work (I'm a peddler), and expect to get another couple hundred thou at the very least from the current Benz this way.

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rdsw
Salem, NH
1984 300SD, 260k miles and counting

Well it makes me wonder whether i should sell the 300 SDL and buy the '84 300 SD. I've seen the service records of the SD for over the last 10 years, totalling $15k. These service records inlcude new brakes, motor mounts, new seats etc. This used auto dealer wants $4k for it and it's in great shape. The 300 SDL needs a new brake job, probably new rotars and suspension system. I need the climate control worked on and the springs in the seats are bad. It does run great though and the body is in great condition. Either way I guess you have to do maintenance on vehicles over 10 years old anyways.