SD Problem Years? - PeachParts Mercedes-Benz Forum

cjbrown · #1 07-01-2010, 12:20 PM

I've been toying with the idea of a bigger more powerful diesel, maybe an S-class with a turbo diesel. I know there were some problem years early on after the mid-80's. Can someone tell my which years were the problem, and what it was?

I recall something of an injection pump or something like that, was a well known failure problem and at that time a very expensive part to replace. Was there an updated part for a permenant fix, or??

I knew at one time about this but it was so many years ago I've forgotten. Seems like it was the SDL's or something, late 80's to early 90's?

Also, any other years/models to watch out for. There are some nice cars out there with reasonable miles and good prices. I'm selling my Duramax so may want to put a nice car in the driveway. The little 240 is nice, but it's really too nice to be a daily driver. I just need to park it in the garage and let it age gracefully.

Thanks!!

vstech · #2 07-01-2010, 12:30 PM

up from a 240 but down from a duramax... SDL sounds good. perhaps an eclass 300D with the 603 in it...
up to 85, issues are equal to the 240, then the 86and up had cooling issues when not maintained... there are fuel leakage issues on them as well. nothing expensive IF maintained. the 350L motors are known for rod bending...
that's all I got.

cirrusman · #3 07-01-2010, 01:45 PM

The 81-85 SD is simpler to work on than the latter SDLs IMHO. I've got no IP problems so far. My '83 SD is a good climber despite what I've heard. I live in Utah and there's a lot of climbing to do here, which the SD tackles with no complaints whatsoever. I can climb up to the snow resorts in the summer at 60 MPH with the ALDA turned 1/2 turn CCW, and not too shabby either at stock setting, although it will take longer to get to that speed if I need to slow down for whatever reason. Check for rust, I've heard of people having problems under the battery tray (not me though). Also, the interior is not as tight as in the 200 series. Mine's all loose and I'm going to have to fix that sometime. The seats are electrical (aka heavier) and damage prone and I wouldn't mind swapping those for manual ones. (Unless I can swap them for an '84-85 set with nice memory settings).
The OM603s had an aluminum head that was prone to cracking if overheated. This engine was used in the 1986 and later w126s. The 3.5 L engine found in the 350 SDL had rod bending problems. This is why the five cylinder engine (OM 617) is the most desired. Found in any 81-85 SD.

noah brinkman · #4 07-02-2010, 10:39 AM

I will not be baiased here I have an 86 300 SDL ( my first benz and first diesel)
I am not a mechanic but working on my SDL is easy if 80-85 SD's are easier

it must be a cake walk I've done all my own work so far (and I've done alot of work)

how far is your daily commute (daily miles since you want it to be daily mobile)
I get 26-32mpg no matter how I drive
SD get about the same
300D I don't know but for a daily driver I would stay in the 300 group

85 and older adjust valves every 12K
603 need no adjustment

the interior is pretty much the same exterior styling is close
86-87 SDL looks alittle less dated if you change headlights and rims

SDL has about 28 more HP from the factory

I wouldn't buy a 350 SDL but thats me seems like after "THE WALL" came down
mercedes lost alittle soul I like rollin the classic iron

what ever you buy we can help you through any issues you have to keep it a daily driver
and as ROY said to me "we need to get this thing back on the road where it belongs and keep it there"

cjbrown · #5 07-02-2010, 12:23 PM

Thank you all for the reports.
I found pretty good info on the good and bad for the various years on wikipedia - a pretty good source of data on all mercedes models and their engines. Really handy for years/models/engines/production numbers, etc.

So the die-hard 617 motor is the 5 cylinder going way back, came in the 81-85 300SD. Understandably these are the true tanks that will run forever if taken care of. BTW, valve adjust is one of the easiest I've ever done on my 616. You just have to have the bent 14mm wrench set which I was able to buy used on ebay for $50.

All of their diesel models went to the updated 603 motor in 85 and that's where some of the problems started. 86-87 had the oxidizer trap that got replaced or removed under warranty. That was the culprit for blowing up turbos and etc. They also have an aluminum head that can crack if the motor overheats. Apparently this was more or less dealt with and reports are that these are also solid high-mile cars.

By 90-91 they had fixed the prior issues and decided to bump the displacement and resultant power by adding another cylinder using the same bottom end as the 5 cylinder which didn't work out all that well. These were the 350SD and SDL models, only built for two years for a total of about 2000 +/- cars. Although MBZ never formally recalled them, they did replace a LOT of those motors under warranty. There must of have been an upgrade to the rods as the new motors were fine. I understand they all have problems with enough miles, city driving miles being the worst for them, but if you can verify a replacement motor in them they are really nice cars.

My driving is pretty reasonable annually. Between 2 drivers and four cars we put on about 15K miles. My office is 4 miles from home, and usually go home for lunch. So I put about 20 miles a day on, and drive the other cars or the motorhome on the weekend and for any trips. My truck has gotten about 4K miles year for the last 3 years, but we sold the boat so now it just sits. Wifey's bimmer convertible gets about 3K a year, but she's been out of work and mostly home. The new scion xb runabout (toad for the motorhome) gets about 8K a year and our new studen driver has been relagated to that one for now.

So a SD for me would see maybe four or five thousand miles a year max. I would like to have one because they are luxury, beautiful, and still econonical with their diesel engine. I would park the 240 in the garage and drive the 300. I am able to perform all maintenance and repairs regardless of what they are, even down to trans or engine r&r. I've done body work and paint as a hobby for almost 40 years, and fully capable of complete restoration work. I have a doctorate in 'fix-it'.

Here's an interesting ad listing. I think the car is a few thousand over-priced, but a nice example nonetheless. I've written them to ask what they have on the engine status. If it has a mercedes replacement motor in it I would love to own it. If not I would pass. I'll post the link here, it will work as long as the ad listing is active. It's a 91 350SD with 64K miles, asking $12,995:
http://www.autotrader.com/fyc/vdp.jsp?ct=u&car_id=281617475&dealer_id=57334618&car_year=1991&rdm=1278086790742&lastStartYear=1981&model=&num_records=25&systime=&make2=&highlightFirstMakeModel=&start_year=1990&keywordsfyc=&keywordsrep=&engine=&certified=&body_code=0&fuel=Diesel&awsp=false&search_type=both&distance=0&marketZipError=false&search_lang=en&sownerid=74651&showZipError=y&make=MB&keywords_display=&color=&page_location=findacar%3A%3Aispsearchform&min_price=&drive=&default_sort=priceDESC&seller_type=b&max_mileage=&style_flag=1&sort_type=priceDESC&address=92870&advanced=y&end_year=1992&doors=&transmission=&max_price=&cardist=981&standard=false&rdpage=thumb

I'll save the main two pics to my photobucket acount so it will stay here:

babymog · #6 07-02-2010, 12:37 PM

A few corrections Chris. Be careful, Wikkipedia is user-authored, some checks in place but not a perfect source.

The 6th cylinder was added in '86, and the 6-cylinder OM603/OM606 has a better reputation for bottom-end than the earlier 616/617. The "trouble starting" wasn't true at all, has the same HVAC system, same problems with rust and expensive suspension maintenance, and I've not yet had a problem with the aluminum head (knocking on wood) in any of my 603 cars, ... all you really lose going to the 60x engine is some noise, some pollutioin/smoke, and a set of valve adjust wrenches in exchange for more power and efficiency.

The 3.5L 350SDL/SD actually didn't gain power, about the same hp as the earlier ones, just at lower RPM. You lose operating rpm. Later in the 140 body the rpm went back up and it did increase hp.

Be careful to whom you listen about the 61x vs the 60x engines, very few have owned both, and it's uncommon for one who ones one to claim the other is better. Kind of a Chevy-Ford thing here. Personally, I much prefer the 60x engiines, and I'd love to have a nice '90/'91 SD/SDL with the more refined interior, nicer sound system, body cladding, etc. and drop a 603.961 in it.

tbomachines · #7 07-02-2010, 12:38 PM

I would stay away from the rodbender regardless of whether it has a replacement engine or not...I have heard that the replacement engines are not much better than the originals in some cases, pretty much hit or miss.

cjbrown · #8 07-02-2010, 02:17 PM

So the new motor for 86 were all 6cyl? The 60x-series diesels?

Just the 350SDL for 91-92 were the rod benders?

BTW, I got a reply on the ad car, it sold yesterday. I wonder what they got for it.

I love any older car with mileage like that. My 240 is just sweet, unmolested, really nice. I know, cars can still get trashed by 100K. IMHO, over that mileage requires someone that actually cared for and took care of their car if they're nice.

Skid Row Joe · #9 07-02-2010, 02:23 PM

Quote:

Originally Posted by cjbrown

So the new motor for 86 were all 6cyl? The 60x-series diesels?

Just the 350SDL for 91-92 were the rod benders?

BTW, I got a reply on the ad car, it sold yesterday. I wonder what they got for it.

I love any older car with mileage like that. My 240 is just sweet, unmolested, really nice. I know, cars can still get trashed by 100K. IMHO, over that mileage requires someone that actually cared for and took care of their car if they're nice.

How much $$$ is your budget for this new acquisition?

What do you want, $$$ for your Duramax?

cjbrown · #10 07-02-2010, 02:34 PM

Quote:

Originally Posted by Skid Row Joe

How much $$$ is your budget for this new acquisition?

What do you want, $$$ for your Duramax?

I haven't set a budget. I'm one of those that decides what I want, or finds what I want, then figure out how to pay for it.

I would love to find a low to mid mileage one (90K to 120K) in the five thousand range that maybe needed some TLC. Put a grand or two in it and have a really nice driver. Don't know if that's realistic or not. I sure don't want to buy one and then be faced with a ten grand engine replacement.

Here's my ad on the dmax, currently it's $22,500:
http://orangecounty.craigslist.org/cto/1818361351.html

Got a trade?????

Skid Row Joe · #11 07-02-2010, 03:38 PM

Quote:

Originally Posted by cjbrown

I haven't set a budget. I'm one of those that decides what I want, or finds what I want, then figure out how to pay for it.

I would love to find a low to mid mileage one (90K to 120K) in the five thousand range that maybe needed some TLC. Put a grand or two in it and have a really nice driver. Don't know if that's realistic or not. I sure don't want to buy one and then be faced with a ten grand engine replacement.

Here's my ad on the dmax, currently it's $22,500:
http://orangecounty.craigslist.org/cto/1818361351.html

Got a trade?????

In that case buy a 2008 E320 Bluetec. -They're "big and powerful,".......@ 400 ft. lbs. of torque & 269 HP, that should get your attention when driving one. That's what I'm shopping to upgrade to.

My sig. car is for sale elsewhere on the Net. I "don't have a budget" either......I just pay cash.

compu_85 · #12 07-02-2010, 03:56 PM

Quote:

Originally Posted by cjbrown

I've written them to ask what they have on the engine status. If it has a mercedes replacement motor in it I would love to own it. If not I would pass. I'll post the link here, it will work as long as the ad listing is active. It's a 91 350SD with 64K miles, asking $12,995

If the engine is new and the suspension is new I'd consider that price. If not then no way. Remember age degrades rubber, so even with that few miles it probably needs bushings and other parts replaced due to age. That car does have the auto locking differential, which is nice.

If the engine is original I would not buy it either.

-Jason

Hit Man X · #13 07-02-2010, 06:04 PM

Quote:

Originally Posted by babymog

Be careful to whom you listen about the 61x vs the 60x engines, very few have owned both, and it's uncommon for one who ones one to claim the other is better. Kind of a Chevy-Ford thing here. Personally, I much prefer the 60x engiines, and I'd love to have a nice '90/'91 SD/SDL with the more refined interior, nicer sound system, body cladding, etc. and drop a 603.961 in it.

Exactly, you have to own both before you can dismiss one or the other.

A properly running 617 is quite smooth and linear as is the 603. New injectors made a world of difference in my SD to smooth out power delivery and response. I am still shocked at the gains they provided. My SDL seems to have a broader powerband

Another big plus for the 603 is the better A/C compressor too.

You really cannot go wrong with either.