1987 300SDL vs 1991 350SDL - PeachParts Mercedes-Benz Forum

Cr from Texas · #1 09-20-2008, 03:22 PM

I'll never sell my 83 300D turbo but I could use another diesel with more passenger room.

I've located these two locally and they both are pretty clean and rust free (Texas cars). From a search, I know the 1991 350SDL could be a rod bender. The 1987 300SDL supposedly has a rebuilt engine.

Any advice as to what to look for on these particular models to avoid known problems?

If I buy one and the engine fails, how hard would it be to drop in the 617 drive train from my 83 300D?

94mgm · #2 09-20-2008, 03:30 PM

1: Don't molest a 300D you bought new.

2: Don't buy a 350SDL.

3: Don't buy a Rebuilt 300SDL unless you know how it was done and who did it.

compu_85 · #3 09-20-2008, 03:36 PM

Quote:

Originally Posted by 94mgm

Don't buy a Rebuilt 350SDL unless you know how it was done and who did it.

Fixed your quote

With a good engine the 350 is a very very nice car. Lots of power off the line, plus you get the updated interior. But beware of getting a bad one... there is more then one bad one out there! The reason I bought mine is because it got a new engine in 2001, and I was able to call the shop that installed it and talk with the tech who did it, and found build dates of 1998 on the motor itself.

A properly rebuilt / "factory good" 350 with a nice updated interior and options not available on the 300s (like ASD, passenger airbag, 10 speaker stereo system...) is a great proposition IMHO.

-Jason

Cr from Texas · #4 09-20-2008, 03:45 PM

Quote:

Originally Posted by compu_85

Fixed your quote

-Jason

Jason the quote was correct.
One car is a 1991 350 SDL, the other is a 1987 300SDL.

I would consider molesting my original 83 300D because the body has issues. Not rust but I had hail damage repaired in the late 1980's on the hood and roof. That repair didn't last and is starting to peel revealing brown primer. Left side has a dent in both doors from a careless driver (no note left) trying to pull in or out next to mine in a parking lot. Anyway, mine is still drivable with no issues other than appearance. Body repair and total repaint is about the same cost as one of these SDL's. I'd also get some needed rear seat passenger room.

Hatterasguy · #5 09-20-2008, 03:50 PM

I wouldn't touch a rebuild engine unless you know the rebuilder. If they sent it to a Chevy shop the quality is crap.

The 350's are good cars, if its running fine and not burning oil I'd go for it. If blows deal with it than.

Cr from Texas · #6 09-20-2008, 03:59 PM

Quote:

Originally Posted by Hatterasguy

The 350's are good cars, if its running fine and not burning oil I'd go for it. If blows deal with it than.

I was leaning toward the newer 350 but isn't this the rod bender model? 1991 350SDL?
Are there engine or head casting numbers I should be looking for to either avoid or seal the deal?

TMAllison · #7 09-20-2008, 04:05 PM

Possibly with the exception of the tail end of 93 production, ALL 3.5's were benders. Some crate motors used as replacements got upgraded rods I believe.

Sixto (among others) would know much more.

ottomann · #8 09-20-2008, 06:50 PM

I would refrain from doing a motor swap in a 350SDL unless you have a donor car of the same basic body style. I was shocked at how many things from the donor were necessary.

sixto · #9 09-20-2008, 11:49 PM

603.96 in place of 603.97 is plug-n-play.

A 3.5 with original engine is a crapshoot, particularly one for sale

Evidence of a factory crate engine still under warranty would seal the deal for me. Otherwise it has to be priced such that $2000 for a 3.0 swap down the road makes financial sense.

Sixto
87 300D

redassag00 · #10 09-21-2008, 12:33 AM

^^^

My 300SDL have the engine replaced by a dealer, I have paperwork etc. Almost 10K!

amosfella · #11 09-21-2008, 01:50 AM

would not a 606 from a E300DT just plug and play as well??

sixto · #12 09-21-2008, 03:05 AM

It's basically the same block but the 606 turbo has an intercooler to contend with, radiator fittings in different locations, different oil cooler line attachments to the filter block, etc. Not to mention 96-up have throttle by wire. That means a lot of electronic bits to transfer or downgrade to 603 IP. Then swapping a pressure wastegate actuator...

Sixto
87 300D

amosfella · #13 09-21-2008, 04:00 AM

well, I did know about swapping out the IP from the 606. I was thinking about grabbing the guts from the 606 ip and putting them in the 603 IP. a wastegate actuator isn't a big deal. install a rad and intercooler from a 606, not a big deal as I see it. anything else off the top of your head??

Hit Man X · #14 09-21-2008, 04:21 AM

617 in a 603 car is silly. Reverse progression in technology. A properly running 603 is a great motor, better than the 617 in almost all respects.

I'd do the 350SDL, run it until it breaks. Drop in a 3L and off you go.

"rebuilt SDL" could be anything, nothing I'd be interested in.

Jeremy5848 · #15 09-21-2008, 12:27 PM

The '87 300SDL may be OK if the seller has the service records so that you can see who did the work and what was done. If the rebuilder is someone you can trust, the car may be OK although not as fancy as the later 1991 model that you are comparing. A car with no records or a rebuild by someone who doesn't know Mercedes should be waved off. Both cars should be considered only at a very low price to make up for the risk you are buying.