1993 300 Sd
 

I've been looking at a 1993 300SD. Any opinions to this car? Any major problems with the engines? etc... Looking at one with 165k, great interior and exterior. :bulb:

The engine in this car has a terrible failure rate, somewhere between 40 and 50 percent it memory serves me. If the engine has been rebuilt with the newer head? it should be alright. Also check to make sure that the ac blows cold!! Ac evaporator is also a common problem on these cars and a very expensive one to repair. Options would include a power rear window shade and well that is all I can think of, because this car is on the short wheelbase.

I'd heard there were some engine problems. I think it's with the heads, the same as with the 1987 SDL's and the 1991 350's. Almost sounds like all the 603. engines have issues with the heads. I'm wondering which was the better year for the 603's. I imagine the newer model the better. I was particularly interested in the 90's SD.

Do a search on 'rod bender'

Tom,

The older 603's had issues with cracking of cylinder heads. These are in the '86-'87 SDL's.

The one you are looking at is a 3.5 litre engine and it suffers from bent connecting rods on occasion. The problem is that you do not realize that the rod has bent until the engine has ovalized the cylinder and is now drinking hugh amounts of oil. The cost to repair the problem is generally 2/3 the value of the vehicle.

Personally, I would avoid any SD or SDL from '90-'95 unless you are a gambling man and can afford a $7K loss. If a rod bends, you will be staring at approximately this number to correct the problem.

Thanks Brian, That's what I had heard about these models. I just needed someone to back it up. Would there be a different marking on the engine head as a replacement? Now, my 86' SDL seems fine and it's got the origional head on it. So far so good.

With regard to the heads on the earlier 3 litre engines, such as yours and mine, there is a casting number above the #2 injector. There are two digits, the second to the last group of two, that represent the casting number.

If you have the original head, yours is probably a "14". Mine is original and it is a "15". There are later versions of this number and the most recent, AFAIK is a "22".

Remember we are talking about head replacement on the earlier engines. The later 3.5 litre engines have no head problems.

If the engine has been updated I would buy it. I like the W140, just remember it is a W140.

They all seem to need evap cores at some point in their lives figure $3k.

The heads on the 350's are fine in fact if your 603 cracks its head one from a 350 would be just fine. But the rods can bend. I think you are taking a 50/50 shot when buying one.

Brian, I wanted to let you know I have the #14. It has 168k miles. Is there any warning signs on these particular heads? Mine is running fine and I change my oil every 3k miles without adding any oil.

Tom, there are no warning signs of impending doom. Just make sure that it does NOT overheat. If the temperature gauge climbs up over 110 C., get the vehicle on the side of the road immediately. Have it towed if necessary.

If the head does crack, you will notice pressure in the cooling system the following morning, after it cools off. However, this also can be a bad head gasket. In any case, the head must come off to determine the problem.