Haven't heard much about the 1991 350 SD's. Anyone care to share their experiences, good or bad? Whats the differences to the 300 SD?

Very cool, and a rare car, basicly it's a short 350SDL. Depending on which 300SD your talking about, the 1992+ were W140's and a completly different car. The 1981-85 300SD is also a W126 but I think the 350SD would compare more to your SDL. Just watch out for the 350 engine, other than that they seem to be pretty reliable.
Do a search.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Thanks Hatters. The 603 engine is in the 350SD correct? So far, knock on aluminum, I haven't had any problems with mine. If i'm not mistaken MB corrected the head problem right? By putting a different head in a re-call? How would you know if your engine head had been changed out?

With the 350's it's not the head you have to worry about, they fixed that problem. It's having the connecting rods bend and ruin the block, a new engine runs $12K. Miles are good, if you are looking for one, try to find one with over 200k, hopefully it will have one of the good engines. Do a search there is a lot of info about these engines.

Cool cars though, I have only seen one once, I think there were only 2,500 or so sent to the US.

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2016 Corvette Stingray 2LT
1969 280SE
2023 Ram 1500
2007 Tiara 3200

The confusing part is that both the 3.0 and the 3.5 are OM603.xxx engines. You have to know the rest of the numbers, which I don't have off hand. The 86 and 87 3.0 is the head cracker, and the 3.5 is the rod bender.

Just so you don't think I'm knocking these engines, mine is the glow plug sticker. Make sure you do plenty of research before jumping into a 350. Much has been written about them here and is available by hitting the search button at the top right of the page.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

603.96x = 3.0 = head cracks potential, new head solves problem

603.97x = 3.5 = bent rods potential, new block solves problem

603.xxx = fast, smooth, quiet

Sixto
95 S420
87 300SDL

Not picking nits here. I just thought the fix was beefed up con-rods, not replacing the block?

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past MB rides:
'68 220D
'68 220D(another one)
'67 230
'84 SD
Current rides:
'06 Lexus RX330
'93 Ford F-250
'96 Corvette
'99 Polaris 700 RMK sled
2011 Polaris Assault
'86 Yamaha TT350(good 'ol thumper)

I think he meant "new short block." There were scads of updated parts, and when a 3.5 failed under warranty MB replaced the whole engine. It wouldn't be sufficient to just replace the rods because, by the time you find out that they're bent, the cylinders are ovaled.

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Rick Miley
2014 Tesla Model S
2018 Tesla Model 3
2017 Nissan LEAF
Former MB: 99 E300, 86 190E 2.3, 87 300E, 80 240D, 82 204D Euro
Chain Elongation References

go gas: no head cracking, no oval cylinders, just $$ for gas. But considering that a 350SDL sells for ~3k more than a gas powered car, the economy advantage is nullified.

Great time to pick up a gas hog on the cheap right now.

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'90 300SE 298k
-300K and it gets put into retirement.
'80 300D 255k Purchased new by family in 1980.

Had a:
1973 220 (gas)
1980 300SD
1992 400E

I've heard that the 380's weren't that bad on gas. I still seem to see quite a few of them around. I also occasionally see some 300SE's but I don't know much about them other than they're 6 cyls. I'm sure they're not as quick as a 380.

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DJ


84 300D Turbodiesel 190K with 4 speed manual sold in 03/2012

I rode in a 350SD not long ago, 250K or so on it, no engine work done.

It was neat that it was a newer w126, no faded gauge needles, and no for many of the other things age brings the w126.
But otherwise, I'd rather have an SD with the OM617.
The owner was of the same opinion.

Nice car though..

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

Gotcha

__________________
past MB rides:
'68 220D
'68 220D(another one)
'67 230
'84 SD
Current rides:
'06 Lexus RX330
'93 Ford F-250
'96 Corvette
'99 Polaris 700 RMK sled
2011 Polaris Assault
'86 Yamaha TT350(good 'ol thumper)

You said that better than I could have said it. What I meant to say, though, is that if you find a car with records to show that the short block, long block or entire engine has been replaced, it should last a long time.

Same with the 3.0s. I haven't read of replacement heads cracking even if there is a long string of replacement head part numbers.

Sixto
95 S420
87 300SDL

Driving a 350SD is like driving a gas car. You hit the pedal, and it scoots off immediately.

On the highway, you can barely make out the engine above the sound of the tires.

It is a grunter of an engine, so peak power is reached at quite a bit lower rpm than the screamer 3.0 liter version.

It is all the more easy to fall asleep behind the wheel on 400+ mile trips.

Don't get me wrong, the 300 is nice. But it is also loud. I don't mean at idle, I mean at 80 mph in 4th gear. The ONLY time the 300SDL gets quiet is AFTER 100 mph. Why did Mercedes design this US diesel to quiet down after 100 mph? We don't exactly have loads of Autobahn highways.

There is a spot that gets noticeably louder in the 350. It occurs at 85 - 90 mph, then it gets quiet. Even at 115 mph, it is still hard to hear the blasted thing!:p

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1987 300SDL (324000)

1986 Porsche 951 (944 Turbo) (166000)

1978 Porsche 924 (99000)

1996 Nissan Pathfinder R50 (201000)

Guys,

I've wanted a 126 350 ever since I drove one a few years back...smooth, quiet and very powerful. However, I digress...

Was it ever determined why some 350s were bending rods?

The rods are massive, you'd think it'd take a tremendous force to bend
them...I can't believe that could happen from normal operation alone(?). I keep
thinking that coolant must have been seeping into the cylinders from faulty head
gaskets or something...I could possibly see that doing it, over time.

What do ya'all think?