I have read various threads about the troubles with the 350SD. While not as solid as the old 5 cylinder diesel, apparently the 6 cylinder model from '86 to '90 was still a pretty good engine, if well maintained. Is the engine in the '92 300SD improved over either of the other 6's?
Yes the 3.0L six is a fine engine, smooth and more powerful than the old five cylinder engine but not as tough as the old five. If you want a
300SDL buy an '86 or '87.The 3.5L six is an engine to be avoided, IMHO. It's prone to bending its connecting rods. When bent, the piston attached to a bent rod is no longer square to its cylinder so the cylinder walls get scored and the owner has an expensive mess to fix.
The 3.5L engines' durability varies greatly, there's no particular mileage to these failures so one just doesn't know. Replacement connecting rods have been modified and they seem to be OK.
These 3.5L 350SD and 300SD cars are often bought used by the unsuspecting and have caused much unhappiness.
Yes, check with Mercedes to see if the engine has been replaced or repaired & updated by them, also check to see if the Evap. core has been replaced...this $3000 repair (have to remove the entire dash assembly) that will ruin your day.
I agree with all that because i have encounter an MERC 300SD USA which have the most terrible idling/ vibration problems..
CSC
If the engine has been serviced and replaced with that common problem then I'd buy it without a doubt.
MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.