Engine Head serial number - useful?
 

Hi, I was wondering if knowing my engine's head serial number is useful for anything. I'm trying to figure out if my car's engine is original or maybe a factory replacement.

It's a 1992 300SD with a supposed 603.971 motor. I know those could have weak rods but my engine has 260k miles on it and going pretty strong (IMO).

The head serial number is 603 011 21 01. I don't have much history of the car. Can't find which dealer this was serviced in FL. It has records from an owner in MD - an extensive collection which I'm going to go through again.

Unless Im mistaken the models plagued with weak rods would be the 3.5L diesel in the 350SDL/SD. I have yet to read anything about the lower end of a 3.0 being a problem.

I don't think a 92 would have come with a #21 head from the factory. Look on your bellhousing on the passenger side, see if you see a tag like this one:

http://www.peachparts.com/shopforum/...1&d=1229285289

Casey, even though the car is badged as a 300SD it still has the 3.5l engine :)

-Jason

My '91 had no metal tag, just a paper one (illegible) on top of the bellhousing.

The chronology of the heads has been discussed, I was told that my '91 should have come with a 17 head originally. I don't know about the '92 but also have not heard of a 21 head, hopefully it is a turbo head.

Had your 91 gotten a new engine?

That's what I never figured out. Block is still sitting in the shop, no idea what to do with it.

The sticker is just like the VIN stickers on all of the body panels, I'm guessing that it is the original block and that's how it is identified, with a VIN sticker at the top of the bell-housing area.

Had a 22 head though, that's all that mattered to me.

engine #s
 

Casey the 603.971 is the 3.5L (maybe rod bender) the 603.960 is the 3.0L version. Cheers