Howdy all,

New to Benzes and the forums, not new to diesels (VW TDI, Ford megatruck)...

I have recently acquired my step-grandmothers pristine dealer-maintained 91 350SDL (106k miles) from her estate. I have searched here and elsewhere on the web for information on preventative maintenance on these cars and what I have found is pretty slim. I'm sure there is good research and documentation on things that can be done to better your chances of living for a long time with this engine, its just hard to sort through all the alarmist "rod-bender" crap to find it.

So I'm looking for some help; I've seen posts from Larry Perkins and others that look to have promise. What sort of maintenance can I do right off the bat to up my chances? (locktite oil baffle bolts - is there a DIY doc on this anywhere? bypassing EGR, etc?)

What I'm not looking for is more "rod-bender!! RUN!!!" alarmist postings -- and I don't mean to offend anyone by saying that. Just seems to me that working to solve the problems is much more productive, and I already own the car and its running well.

Thanks in advance for any help/advice/etc.
Steve
Tampa, FL
91 MB 350SDL
00 VW Golf TDI
91 Range Rover

Maintain it, that's the best you can do. And yes, drop the EGR.

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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]

Throw away the EGR and drive it.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

Being a 350sdl owner I know all bout em...bring it over anytime round FEB. I'll do all maint. for free....ready for pickup round Nov.

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

For God's sake, dump the rod-bender as fast as you can....... They get run up in price routinely on EBay by people who don't know about the issue, so that's the best venue.

Ken300D

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1982 300D at 351K miles
1984 300SD at 217K miles
1987 300D at 370K miles

One oddity I read, all early 603s had much poorer head gaskets than the later ones. Just something to think about as a potential cause of their issues.

I'd keep the car and drive it until something potentially happens with the motor. '89+ have all the nice interior bits. If something happened, you could either rebuild the 3.5 or just toss in a 3.0 and motor on.

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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]

Preventitive maintence -> stop listening to people....

regular oil and filter changes using diesel rated oil preferably sythetic, (chose temperature range that fits your driving climate)

Change your fuel filters,

no valves to adjust on that engine,

Change tranny fluid and filter.

Basic car maintence stuff, keep it clean, underbody washed down, check suspension and alignment.

Those are nice cars, and the rod issue gives some warning before failure, which means you can shop for a new engine for a while.

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1984 Euro 300SDC, (4spd standard)
1986 Toyota Landcruiser Diesel HJ60 5spd X2

Gone but not forgotten (some sold, some stripped)
1983 300 SD, 1985 300 SD, 1983 240D, 1986 300 SDL, 1985 300 SDL, 1983 300 D, 1984 300 D, 1985 300SD, 1987 300 SDL, 1983 300 SD, 1985 300 TD Euro, 1983 380SEC, 1990 300 D, 1987 300D, 1982 300D, 1982 300D, 1994 E420, 1987 300 TD, 1987 300 D, 1984 300 D

There's only as much alarmism around here as there is denial

The only known way to solve the problem is to get redesigned rods in there either through a rebuild or a whole new block. That's an extreme measure for an engine that shows no symptoms... at least you didn't describe any. They don't all fail, just the ones owned by people who join this form

No one has found a way to maintain the car around the defective rods. No one has found the driving style that will prolong the inevitable Drive it like you would any other car. If someday you notice oil consumption you can't attribute to an external leak, you'll know its number is up. From the first time you have to add oil between changes (or the low oil light comes on), you'll have lots of time to enjoy it while deciding on a course of action.

I have a couple of bent rods out of such an engine. If you'd like to examine them to figure out the cause, you're welcome to them. Maybe you can find the elusive driving and maintenance regimen that would have kept them true.

Sixto
93 300SD 3.0

dammit..I knew I shouldn't have joined this forum

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1982 300TD 210K miles ("The Replacement" aka "The Anvil") - SOLD
1979 300SD 245K miles (never ending project)
2007 Pinarello F3:13
1995 Ducati 916 (SOLD, sniff)
1999 Ducati 900SSie (SOLD)

have you gone to a mercedes dealer and asked them check to see if the engine could have been one that mercedes replaced, u know they did that on some one owner cars.
if you do decide to drive it out and not disassemble it, keep my number,i have 5 now and find it a real challenge.
larry perkins
lou ky

i saw your post earlier and made a short comment,now i have more spare time as the work day is close to ending.
you are looking for suggestions,so i asked myself,what would i do if i owned your car.
i would drain all the oil, remove the oil level sensor at the drivers side of the oil pan and go fishing with a magnet around the base of the oil pump. once the oil sensor is removed(5 minute job) you can use a magnet with a flexible shaft and pretty much get to all sides of the oil pump base. i sent brian carlton pictures of screws that rotated around the base and one that showed the hole that the washer made thru the pump screen and he posted them. if i found any loose parts then the pan would have to come off. if i didnt find any loose parts i would drive the car
to louisville and park it till i could remove the engine,address the baffel plates,replace the rods,rebuild the turbo, assemble the engine measuring every part,replace if out of spec and have a unit that would run 500k in my opinion.
now if you just drive it,at the least go fishing often(with the magnet) when the oil pump locks up it is a total desaster.
hope this helps
larry perkins

Keep air filter (15K), oil (5K) and fuel filters (15K) changed regularly and enjoy it. If it starts using oil or is using oil, try to rule out the turbo or valve seals. If not turbo or valve seals, get rid of it or pull the head and hope it is just a head gasket failure. If you catch the head gasket failure early enough you may avoid the bent rod issue. Just my opinion. As Larry said go to any Mercedes dealership and let them query for any warranty work.
JT

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JT
1991 350SD 216,000

Hmmm...

Nothing much you can do. Mines been through two engines (one built in 1991, the other 1995), and the third is a used 3.0 liter.

My father has been driving a black 350SDL (I drove it 2,000 miles before him) for 21,000 miles: Always burning about 200 - 250 miles to a qt CONSISTENTLY.

Just yesterday he took a trip to Concord, NH and it used 2 qts in 100 miles. It now has a slight miss at idle (very subdued, but its there). The engine fires very quickly at near 0 degree temperatures, idle is smooth (except for that very small miss), valve seals have been done (that was ruled out long ago).

I bet that thing is going south. There is nothing on it that hasn't already been checked (turbocharger, vacuum pump diaphragm, etc.) If a 350 is burning oil, no matter how much, its on borrowed time. In my experience, I wouldn't bother to purchase one, even with the "upgraded" engine design since that one failed on me as well (rounded out the cylinder...Cross hatchings missing in spots and ridge was gone in #1. Not to mention the piston shattered).

When they're running well, they're easily the quietest, most flexible and refined stock 60x engines ever built.

hey guys, think of this,the rod failure is for sure in my opinion,now the rod bending causes excessive wear to the cylinder walls, motor is basically a throw away engine,now you say swap a 603.960 in,well those engines all have heavy miles and need help,why not repair the 3.5 and wear it out?
also i am about 2 months away from finishing my project of converting the 3.5 to 87mm pistons and replaceable sleeves,so heck one of them has to go 750k,lol just bragging a bit.
larry perkins

Mine was in a wreck with a deer. smashed the front end and it wouldn't shut off. I see all the anti freeze draining out of the car and it just sits there purring along at 700 rpm, like nothing happened. I had to use the jack to open the hood enough to get to the shut off. It ran for about 5 minutes without AF.

Got it fixed, the engine no worse for wear, as it idles at 700 just purring along.
drove it 80 miles back home from the shop, no problems. Took a oil sample, no metals or conditions out of normal. Just like all the other oil samples I take at oil change time (three years worth). May run for another week, may run until I'm in the grave. who knows...

Just drive the heck out of it and ENJOY IT. Nobody knows what is going to happen in the future...

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71 220D 169K wrecked
83 240D 118K sweet 4 speed
91 350SDL (one of the 60% good engines) 156K
84 300d (loaner to my sister) 189K
79 300SD (partswagen)
86 420SEL partswagen
70 220d (partswagen)
68 280s GASSER!!! under construction now
85 300sd 310K miles winter beater car retired
93 300d 2.5 turbo 168K wife's car
83 280SL euro 5 speed 155K
69 250S newest project 54K