I think you mean big brother, the 606 turbo is an even better engine. but as you said the GP's are troublesome.

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Current:
05 E320 CDI
07 GL320 CDI
08 Sprinter
05 Dodge Cummins
01 Dodge Cummins

Previous
2004 E55 AMG
2002 C32 AMG (#2)
1995 E300
1978 300D
1987 300D
2002 C32 AMG(blown motor :[
1981 300SD
1983 300SD
1987 300SDL
2002 Jetta TDI
1996 S420
1995 S500
1993 190E 2.6
1992 190E 2.3
1985 190E 2.3 5-Speed

Drive both, then decide.

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I'm not a doctor, but I'll have a look.

'85 300SD 245k
'87 300SDL 251k
'90 300SEL 326k

Six others from BMW, GM, and Ford.

Liberty will not descend to a people; a people must raise themselves to liberty.[/IMG]

I have one of each, as my signature shows. The W123/617 seems to me to be somewhat simpler to maintain, both under the hood and in the cabin, especially if you want to do as much as possible yourself. The W124/603's power, quietness, and smoothness appeals to my wife. We haven't driven the 603 enough to evaluate its fuel efficiency but it is supposed to be 10-20% better than the 617, especially our CA version 617 with the trap cat.

There are more W123 cars with the 617 engine than W124s with the 603. Some 300SDs also used the 617 so parts should be easier to get at your local pick-and-pull. The W124/603 is a more modern car -- it is the first Mercedes of the "new style" that continues today. The W123/617 is the last of the old style that goes back to the 1960s, I suppose. In some ways the two cars are very similar, especially as regards interior and controls. Everything is in pretty much the same place.

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"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

I can have both cars... but who needs both. I'm selling one for sure. I see things at a glance looking into the hood of the 603 on the 87 300d that don't look too appealing.
1. the front of the engine is very close to the radiator. I fixed the vac pump on my 617 and there was not much room to get it out but I would say there was enough. With the 87 300d I think it'd be painstaking to change even a belt, much less any 'front of engine accessory'. Not a good design in my thoughts.

2. the IP's fuel delivery valves have that stupid 32 tooth socket that you have to spend at least $40 (w/shipping) to get. I own the socket from when I owned an 89 190d 2.5 (never buy again). Nothing wrong with it but why??? Whats wrong with a standard hex like the 617 has on it's delivery valves. It's just another dumb un-needed proprietary tool. I'd trust the hex for better grab with a wrench any day. Just no point to it.

3. The intake manifold is in the way of a bunch of stuff. The 617 put the intake in a non-obtrusive area.


All that in my opinion makes the 617 a better design. There are drawbacks to it but from a design standpoint it's very thought out in terms of placement of parts. To me it looks like the 603 is sort of just thrown together.

By the way... the one I'm buying has no glow light so I'm assuming it's got GP issues. What issues are common. I saw someone noted Glow Plug issues on this engine? This will be my first time working on the car.

__________________
-E300d '99 350k
-Suburban '93 220k
-TDI Jetta '03 350k
Sold
-F250 '96 7.3
-Dodge Ram 12V
-E320 '95 200k
-E320 Wagon 1994 155k
-300d Turbo '87 187k miles
-E320 1994 200k
-300d Turbo '84 245k (sold to Dan62)
-300d Turbo '84 180k
-300sd '80 300k
-7.3 Powerstroke Diesel 15P Van 500k+ miles
-190d '89 Non Turbo 2.5 5cyl 240k (my first MB)
Tom's Imports of Columbia MO Ruined the IP in changing leaky delivery valve O-Rings - Refused to stand behind his work. Mid-MO MB drivers-AVOID Tom's.

I would probably consider a 603 ..... if it was installed in a W123.

It's really a matter of personal preference and you have to decide based on the entire car, not just the engine. Personally, I find the W124 "less than attractive" so I have little interest in owning one. The overall cost of maintenance/repair is probably similar over the long haul. I estimate that I can maintain my W123s for about $.10 per mile over the long term, I would assume a W124 is similar.

There is the advantage, a decent used 603 is a $2k engine. They made less of them so parts cost a bit more, things like the radiator for example. Its cheaper to get a 617 powered parts car, because they made a lot of them.

I don't think the 617 is any more durable than the 603, on the contrary I think everything being equal the 603 will run for longer. 603's don't seem to chug blow by from the oil caps like 617's do, MB improved the bottom ends it seems.

The turbo charged, intercooled 606 pwn's all these engines so it wins!

__________________
1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

It may make the 617 better in terms of design, but only if you're looking at it from a "makes it easier to work on" perspective. The 603 is quieter, more fuel efficient and more powerful. Those were probably the #1 concerns on MB when they designed that engine, not if it's easy to work on in 20 years.

__________________
-justin

1987 300TD, 1987 300TD
2008 R32, 2000 Passat Wagon

Do you want/like to adjust valves or just change oil and filters?

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82 300D....went to MB heaven
90 350 SDL....excercising con rods

Sure, that's why it's called a hobby.

With a mechanical pump, and in a W126 for me.

The 603 takes a little more time to work on certain areas, and is REALLY crammed tight inside the W124. Buckets of blood when doing glow plugs without removal of the intake manifold.

I've owned many 617's in very nice running condition. Inside the cabin of a W126, the engines should be barely audible. There should be NO vibrations. The thrust off the line is quite strong and doesn't trail off until after 4200 rpm or so (like the 350 engine). They should hit 4600 in all gears.

They sound more tractor'ish than a 603/606 (which are very similar in acoustics to the M103/104). But they're a Hell of an engine, and I wouldn't hesitate to own one again. Even with 30K mile valve clearance adjustments.

I don't have a preference. Perhaps the 617 is better suited to all around driving where the 603 is generally more of an interstate cruiser. I personally like the note of the 603 at 5K rpm + better than the 617's (I'm gonna toss parts through the hood).

Personally I like driving the 124, it has a tight modern feel with the lowest chassis resonance in the industry.

The 603 powered 124 is a one-year car, but the 124 was made for many years as was the 603, both have parts available new and used.

Go for the car you prefer to drive/own, most people here side with the car more than the engine. In the 124 you have a choice of three diesels in the US, if the 124 turns you on and the 603 doesn't, get a 606 or 602 powered 124.

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Gone to the dark side

- Jeff

I've got both, a 82 and 87 300TD. It will be hard to decide which one to sell. I love the tone of the exhaust of the 87, it reminds me a little of the 1985 BMW 535i that we owned. The 87 makes me want to try other Mercedes diesels. The thing I like about the 87 is its still mechanically injected. The other cool thing I believe is that if its taken care of I don't think it will depeciate in value much in the long term. The previous owner of my 87 said he would buy a brand new 87 300TD if he could.

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Currently driving a very clean 1985 300SD from the West Coast.

Ya, a 617 will always have more torque than a 603 of equal condition. Very simple, 1 less cylinder with equal displacement means larger pistons, which means more surface area per piston, which means more torque. Simple.........

Performance wise, the Finns will tell ya 603, 606 if you've got the cash.

BUT, a 617 can really contend as far as that's concerned too, just ask Forced Induction or (now not a member, he's on another MB forum) Brandon, they're getting lots of power out of 617's and haven't even put larger barrels in their IP's yet..........

As far as Chassis, I love the 126 Short Wheelbase, but wouldn't mind a 603 powered SDL as a family travel car.... Likewise, I'd like a 116 for the styling, a 123 for the cuteness, and a 124 powered by a 606 for my muscle car.........

Doesn't hurt to dream hey?

But, to pick ONE car, a 617 powered 126 SWB.

And, Hattie, I must disagree; the 617 is much more durable than the 603. Most of the "worn out" blowby infested 617's haven't been treated to a regular oil change in the last 10 years, for the same reason that they're cheaply available. Because 603 powered cars cost more on average, they will tend to get better care. Heck, I bet there are 617's running around on cheap Walmart Fram filters with penzoil 10w30 in em for 4k at a stretch!!!

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-Matt

EPA Section 609 Certified MVAC Technician
-----------------
Oil Burner Kartel Member #10

Ahh the smell of Diesel Fuel, it's like coffee in the morning!

My Car:

1982 300SD Turbo Diesel (231,500 miles!) RIP

1984 300SD Turbo Diesel Custom (235,500 mi on driveline.) - On Road!!

www.icsrepair.com

On that note, I still have not heard of an OM60x engine that has worn out from normal use, to this day. Of 603's I know of a few with 400K + miles, and one I've seen with over 500K miles. You see 'em on ebay once every month or two.

I'd think they're at least equal in that regard. I agree that most 603 engines got better care (free trap oxidizer replacement and the fixing of any engine damage caused backed with an indefinite warranty period, for example). while the 606 engines were abused with oil change intervals spread out much too far by the factory (lots of blowby from most 606 turbodiesels in the States averaging approximately 100K miles or so).

At least the 617 has the iron head.

My 617 has had Rotella 15w40 in it for probably the last 20 years, and I know the PO doesn't skimp on oil changes. But at 225k miles its just about shot. On the other hand I have seen some abused 603's that have little blow by or still have suction if you stick your hand over the openning. I have yet to come across a 603/606 that chugs like a lot of 616/7's do. I suspect MB improved the bottom ends a lot.

Now the 606 man those things just rack up the miles. There is no reason they won't last 500k+ miles if you drive a lot and maintain them. I have seen some tight 300k+ mile 606's, real tight amazing really. Also consider that most have had a steady diet of Mobil 1 since new.

Really the car will rot out or will be shot before the engine gives up if you take care of it.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200