86 300SDL Pros / Cons
 

I have read some threads before and am kicking around the idea of buying an 86 300SDL. I am going to look at the car either Thursday or Saturday and am not in a rush. I have a few questions:
1. How to tell if the issue with the head has been resolved / replaced

2. Any other major things on this car to look for. I believe the ad says 258,000 miles so I am guessing I should try to confirm a timing chain replacement ?
What else ?

As a couple we each put 60-80 miles a day on our cars. Now the 300SD is fine and I love the Suburban but the mileage has gotten to the point where we may just use it around town.
Thoughts ? I am also looking at a 97 E320D just for yucks ( 158,000 miles )
Thanks

1. Ask if head gasket has been replaced. Check head number. Check for oil in the antifreeze. Engine running smooth? If rough and burning engine oil,head gasket may be bad at oil passage near #1 cylinder.
Some head gaskets wear out and the #14 head remains good.
2. Vac pump should be the updated model, has screw heads on the front cover.
3. Updated radiator is a plus, necks break off the early ones.

1) How much money are you prepared to spend on maintenance (parts and labor) every year on this vehicle? Give me an average figure.

2) How much time (labor) are you willing to invest to repair it every year on this vehicle? Give me an average figure.

3) Consider the life of the engine to be 400K miles without major expense. Are you prepared to dispose of it for scrap value at this point?

At 200k my original timing chain was still within spec, and currently at 234k my #14 head and original headgasket are performing fine.

A 17/20/22 head and/or newer headgasket is a plus for sure but don't walk away from a good car just because of the #14. If its been cared for and you continue to care for it the head may never be an issue.

100% agree. I've owned several through 250k miles, all chains and heads have been flawless. Current one was pulled apart at 246k and still had all of the crosshatching in the bores, ... these engines are great if not abused.

concur
 

I have a 1987 300SDL with about 50K miles on a factory crate engine replacement with a #20 head. :D

Sometimes you find a good one.

If its been maintained, then the #14 head as said previously is a non-issue. For that matter, a #17 and higher head doesn't mean much if the car has been beaten up.

I have the original #14 head on my SDL - the short block is a MB crate with approx 150k miles, while the actual #14 head has almost 270k miles. The only reason the short block was replaced is when the P.O. cracked the pan at highway speed. The car is still a pleasure to drive, and we frequently take her on long road trips up/down the CA coast without any hesitation.

For piece of mind, you might consider getting a pre-purchase inspection though.

I have read so many horror stories about that car and have seen a nice one fail catastrophically that would not touch one myself at any price. There must have been good reason why the production run was so short. Why not get a 126 300SD instead? Cast iron heads don't care about miles.

So......what's the asking price and any specifics on the car?

Another SDL nay-sayer from someone who has never owned a 603? Always funny!

I've owned two of them and would be glad to own another. They're fabulous cars, wonderful highway cruisers....but they're not for everyone. Nothing wrong with an aluminum head as such....just don't overheat it.

Because a W124 300D with a 603 is... faster, smoother, more efficient, and handles better. Aluminum heads don't care about miles either if they are cared for.

There was a 300TD in the for sale section that at like 490k miles it blew the original head gasket under the original #14 head. And the first response was something to the effect of "typical 603" I about fell out of my chair.

All of this is helpful. The owner is asking $2,550. for it so I am going to see it this weekend if possible. I know it has been for sale for a few months so it may not be in great shape though. The owner has a few other Benz's in his driveway so that could be a good or bad sign. I will update if I get there this weekend. I just found out I am needed at work on Sunday so that leaves 1 day for all the things on my Honey-Do list.

Interestingly enough, every now and then I see this black '87 300sdl that pops up on Craigslist in Santa Ana. I believe it has somewhere around 440k miles or more. From the description, the 603 appears to be all original, and still drives well (and looks good in pics too). However, the asking price at $4k is steep for that mileage.

Not sure the condition of the body on yours but I bought my SDL for that price with 370K on it. One of the best decisions I've ever made. As long as you can be confident in the history of the head on the car (No overheating) a 14 head can be nothing to worry about. I can't wait to hit 500K on mine!