I like the car however I dont really like the 617 for my personal driving habits and style. Great mill but on a 40 mile one way commute with a average speed of 70 they just aren't happy. A 87 sd, oh yeah but, I fall back to my 124 cars everytime. Just the right size and all the other advantages of the SD.




Joe

__________________
Project Smoker, '87 603 powered wagon
Hauler, 96 CTD can you say torque?
Toy 73 Cougar xr7 convertible
Acme Automotive Inc.
Raleigh NC
919-881-0364

Anywhere I can, used r/h bottems, new bottems whatever. It depends on what you have to spend. You can take a r/h bottem and install it in the left. They are around $75-100 used. Pick a parts might let you get 'em in the $25 zone.


Joe

__________________
Project Smoker, '87 603 powered wagon
Hauler, 96 CTD can you say torque?
Toy 73 Cougar xr7 convertible
Acme Automotive Inc.
Raleigh NC
919-881-0364

That SDL does love speeds of 70-80 mph going down the road that's for sure, or maybe I like the speed. It does hold it's on. I try not to push it to hard, simply because of its age. Diesel motors are very tough.

Tom,

I don't think the SDL would be getting "pushed too hard" even if you were going 90 mph for an extended period. The engine speed would be about 3900 rpm which is fine for continuous use with the 603.

Now, try that with a 617 and you are looking at 4200 rpm. Now that is pushing the five cylinder quite a bit. Personally, I would not take the SD up to that speed.

I drove the SDL to work today doing about 80mph and it didn't even seem to be working hard. Out on the open interstates this car rocks.

Please guys. I have trouble keeping those speeds under 100. ESPECIALLY down hills.

For the quietest diesel I've known so far, I'd say the 350 is the best. You cannot even hear the engine at 80 mph. You CAN hear the BFGoodrich Advantage Plus treads making contact with the pavement.

Watch those speedometers folks.

BTW, the 617 seems quite peppy at 70 - 80 mph. After 90 - 95, they start to "die out".

I agree with DSLBNZ, the 617 is fine at 70 mph. Joe P, I don't think you drove it enough @70 mph. My typical cruising speed on the highway is just under 80. I think that is a sweet spot.

__________________
'85 300SD (formerly california emissions)
'08 Chevy Tahoe
'93 Ducati 900 SS
'79 Kawasaki KZ 650
'86 Kawasaki KX 250
'88 Kawasaki KDX200
'71 Hodaka Ace 100
'72 Triumph T100R

I must respectfully disagree here.

Granted my 123 is an '85 so it has the "special" differential, but my biggest complaint about highway traveling is that I have difficulty keeping the car at 65mph. This isn't due to a lack of power; it's due to the fact that the car just keeps wanting to go faster and faster! I'll be driving, and look at the speedo and see that I've crept up to 75 or 80mph, then I have to let back on the throttle.

I'll admit to not having driven a 126 or any 603-powered car (the power sounds nice, but I like my cylinder heads being made out of cast iron, thank you very much ), but I can honestly say that my 123 is the most highway-happy car I've ever owned by a long shot, and one of the most highway-happy cars I've driven. It's as happy as my mom's '90's Pontiac Grand Prix was, and is bounds and leaps better than the '00 Honda my mom currently owns.

Just my $.02...good luck with whatever you decide

__________________
2001 VW Jetta TDI, 5 speed, daily driver
1991 Ford F-350, work in progress
1984 Ford F-250 4x4, 6.9l turbo diesel, 5 speed manual
Previous oilburners: 1980 IH Scout, 1984 E-350, 1985 M-B 300D, 1979 M-B 300SD, 1983 M-B 300D
Spark-free since 1999

Hey Tim,

I'm just curious as to the rpm's of the '85 300D at say 65 mph?

The SD runs at 3000 rpm with the standard 195-70-14's and it is happy up to about 70-72 mph or so. Above that you have to push it, especially when hitting upgrades.

I'm wondering if the gearing on the '85 is taller?

Now here we're talking about speeds, but which is more durable, the D, SD or the SDL? Which automobile has less problems? Which automobile has the most problems? Which is the real work horse? Which of these would you purchase? Interesting!

Brian, yes, the '85 has taller gearing. The '84 and earlier turbos have 3.07 rear end gears, but in '85 they switched (on both the 123 and 126) to 2.88 gears. I'm turning 3000 RPM at 70mph; 65 is a bit lower but I don't remember the exact number (I usually cruise right at 70, unless, as mentioned, the car starts creeping up in speed). According to the shift dots (I haven't actually done this), the car can get up almost to 75mph in 3rd gear! I got the car up to 80 or so when driving back from Texas (bought the car there; federal emissions is a good thing), and she had plenty more to go...I was just too chicken to risk getting the ticket.

Tom, I think that your question is subject to opinions. The 300SDL uses a 6 cylinder engine that has an aluminum head mated to a cast-iron block. This doesn't concern some people, but I refuse to take the risk of the head expanding at a different rate from the block and eventually warping the head and blowing the head gasket, particularly if the car's overheated. Other than that, I don't think there are any reliability issues with the 3.0l OM603, but I'm not sure either way; again, the head issue was enough to turn me off to the idea in the beginning (this is also why I have an M-B instead of a VW).

That aside, IMHO the 126 and the 123 are both excellent chassis, although the 126 is more technologically advanced...meaning it's both more comfortable and there are more parts to break. This is really a matter of personal preference. If you want a car that's rock-solid reliable but don't care for creature comforts, the real way to go is a 123 240D (or Euro 300D) with a 4 speed manual transmission, manual heater/ac (if equipped) controls, hand-crank windows, manual sunroof, etc.

I have to chuckle about the reliability of the 603 with the aluminum head and the 617 with the cast iron head. In theory I completely agree with the reliability of the 617. Just bulletproof with the cast iron block and cast iron head. I recently acquired the 603 in the SDL and it runs perfectly. So, just recently, which one begins to have head gasket problems? Unbelievable, but it is the 617! Pressurized cooling system and continuous loss of coolant and traces of antifreeze in an oil analysis. Not much more you can say

Maybe the 617 has decided to shove it up my *** as payback for purchasing the SDL?

No wonder the it creeps up to 75-80 mph! Those 2.88 gears are what I want in the SD! I've put 215-70-14's on it to effectively increase the speed by 3mph at a given rpm, but the 2.88's would really be the ticket

How many valve adjustments on a 617 would it take to equal the time or cost of replacing the 603 head once?

I have no experience with 603 motors, but I am on my second 617. My first one had to be rebuilt at 217k. Lost compression in a cylinder. My current diesel was rebuilt at 150k as it was run without oil- owner's fault of course. In that case the low oil indicator light in a later car would have prevented the catastrophe.

__________________
'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

Warden your right about opinons. The pasture always looks greener till you get on the other side. Then there all the same. Your probably right about the D's. The 300D that my father owned was great for just jumping around town and overall was good. I just never liked not be able to get the back wheels from leaving a black streak behind me. Course I was 20 at the time and who wouldn't. Now the SDL has some pep. The 123 chassis isn't your statesman car that the SDL is but it's a great car. We all go round and round on which is the better. It's good to get opinions and experiences. It may help someone in deciding on a particular type of chasis, with a diesel in mind. I drove an 87 300D, and I liked it really well. The SDL has more room and does get good fuel milege.