Considering 617 vs 603 - Page 2 - PeachParts Mercedes-Benz Forum

TheDon · #16 10-28-2009, 02:30 PM

Quote:

Originally Posted by Fulcrum525

Unless you already have a 603 and you want and 1985 300CD to compliment it...then I can see a 617 coming into the picture

naaaah.. unless its a 300CD with a 603 in it

Jeremy5848 · #17 10-28-2009, 02:32 PM

I don't really see much difference in maintenance, engine-wise. The 617 requires an occasional valve adjustment but glow plugs require more work to change in the 603. Both require oil and filter changes and all of the other "usual suspects." The SDL will have more creature comforts, which are nice until they break.

For these two specific cars, I'd look closely at expensive things like the a/c and the sunroof. Air conditioning repairs can eat up a couple of thousand dollars very quickly, unless you have the skills and license to DIY. It's not a difficult license to obtain but not too many of us on the forum have one, I suspect.

If either the SD or the SDL has the same early pop-up sunroof as the 124 chassis (and I do not know if either does), reliability was not up to Mercedes usual standards (the later design in the W210 is much better) and repairs are very expensive. OTOH, you can survive w/o a sunroof. A/C may be another matter, depending on where you live.

These are both the 126 chassis, aren't they? There should be a lot of similarities making comparison easier. Budget at least $1000 for the a/c on the '84. It would be nice if you could arrange for an independent mechanic (meaning, someone working for you, not the seller) to do a pre-purchase inspection. Ask about paperwork showing evidence of past servicing. Any car this old has to have had something break and if there are records you have a better idea of how well the POs cared for the car.

Fulcrum525 · #18 10-28-2009, 02:36 PM

Quote:

Originally Posted by TheDon

naaaah.. unless its a 300CD with a 603 in it

Interesting...I wasn't aware that anyone had ever completed such a project. Is there anywhere you can buy a new 603 engine?

MercFan · #19 10-28-2009, 02:44 PM

Quote:

Originally Posted by Fulcrum525

Interesting...I wasn't aware that anyone had ever completed such a project. Is there anywhere you can buy a new 603 engine?

Sure - you can pick on up right here: http://www.mercedesengines.net/ - happy shopping...

TheDon · #20 10-28-2009, 02:47 PM

Quote:

Originally Posted by Fulcrum525

Interesting...I wasn't aware that anyone had ever completed such a project. Is there anywhere you can buy a new 603 engine?

ebay, the forum, etc.. just need to watch.

Jeremy5848 · #21 10-28-2009, 02:49 PM

Quote:

Originally Posted by MercFan

Sure - you can pick on up right here: http://www.mercedesengines.net/ - happy shopping...

A rebuilt -- not NEW -- OM603 from Metric Motors is $8,900. Interesting that they don't explicitly list the 300D Turbo (W124) but only the 300SDL. Granted the engine is virtually identical, wonder why they don't list both?

JEBalles · #22 10-28-2009, 03:07 PM

It really depends on what you're looking for. I'd go for the sdl cause I'd want something different than the 617/616 in my case. Just another project, more to learn about and all the advantages over the 617.

turbobenz · #23 10-28-2009, 03:10 PM

Quote:

Originally Posted by amosfella

I have heard that the 617 engines lose power a lot sooner in life than a 603. They wear the cylinder walls into an oval... The 603 doesn't have this problem, but might in the future have a head problem. If you don't let the 603 overheat, it will give you many years of problem free service....

Where'd you hear that? My 330K 617 has just as much power as my 120k one. Im driving it to texas today for the second time this year even.

The 617 is the better engine. Adequate power, incredibly simple and easy to work one, almost as efficient. The 603 has more small parts to break and annoy you, same with its newer body. also if the 603 ever overheats, its a paperweight.

Hatterasguy · #24 10-28-2009, 03:23 PM

Buy whichever is in better shape. At this point a W126 is a W126.

I prefer the updated W126's becuase you get better motors and brakes. The SDL is a faster more comfortable car. After having owned both I think the 603 is a better motor, but the 617 is pretty good to.

amosfella · #25 10-28-2009, 03:27 PM

Well, I thought I had read that on this forum. As well, a friend that has rebuilt a number of them told me that was a problem. He rebuilds the sd cars as a hobby on a fairly constant basis... He said at 300k it was a virtual guarantee that the engine would need to be bored and have sleeves put in...
As I said, I only heard...

Hatterasguy · #26 10-28-2009, 03:37 PM

Certianly oil pump drive chains, I have seen a number of those go bad on this forum around that mileage.

Most cars are pretty shot at 300k miles unless someone has done a ton of work to them. Its not just the motor.

Jeremy5848 · #27 10-28-2009, 03:50 PM

Quote:

Originally Posted by Hatterasguy

. . . Most cars are pretty shot at 300k miles unless someone has done a ton of work to them. Its not just the motor.

Absolutely correct. That's why it's nice to find a car with a whole bunch of service records, showing what has broken and been fixed. Otherwise you gotta assume it's already broken or will break soon.

Wodnek · #28 10-28-2009, 04:17 PM

The 603 is awesome. Just think of a full size boat getting almost 30 mpg on the highway. My 87 300D is quicker than my 380SL. The 603 is smooth, quiet on the highway, and pulls through the entire rpm range like a train.
The only time you know its a diesel is at idle.

+ no valve adjustments.
+ better fuel econmy
+ more power
+ smoother, quieter
+ simpler oil changes due to better oil filter setup.

- extra maintanance on cooling system
- glow plug job a little more involved

Some maintanance easier on 603, some 617.
trap ox should have been upgraded to a new catylist further downstream.

Both capable of going 350,000 miles