|
|
|
|
|
|
|
#1
03-19-2010, 11:21 AM
|
|||
|
|||
|
How to tell a 300 from a 350
I'm buying a new turbo (rebuilt) and after getting the number off my turbo I searched it and it's the turbo Mercedes used on the 350 motor, not on a 300 like my car. I'm pretty sure this is just someone put this turbo on at some point in the cars life, but I have my concerns that someone may have swapped a rod bender into my car, not just the turbo.
Are there any definitive ways to tell the 300 motor from the 350 from the outside?
__________________
Serenity-86' 300SDL 482,000 miles (on a "14" head!  )
|
|
#2
03-19-2010, 02:31 PM
|
||||
|
||||
|
Here's a link to the thread where I asked the same question less than a week ago. Nothing definitive has come up yet.
Differentiation 603.961 vs 603.971
__________________
 ~Michael S.~ Past cars: 1986 300SDL 1987 300SDL 1982 240D 1982 300SD Current: 1987 300SDL
|
|
#3
03-19-2010, 03:38 PM
|
||||
|
||||
|
Quote:
A 350 would have the later head, so a 14 head would make the motor likely a 300. MB often updates parts with later numbers. Some W126 stuff has W140 part numbers. Jim
__________________
14 E250 BlueTEC black. 45k miles 95 E320 Cabriolet Emerald green 66k miles 94 E320 Cabriolet Emerald green 152k miles 85 300TD 4 spd man, euro bumpers and lights, 15" Pentas dark blue 274k miles
|
|
#4
03-19-2010, 04:04 PM
|
||||
|
||||
|
I don't think 350s came with a #16 head either, so any low number head would dq your engine from being a 3.5l. Getting the 350's turbo is a nice bonus, it spools up a lot quicker then the one meant for the 300.
-Jason
__________________
1991 350SDL. 230,000 miles (new motor @ 150,000). Blown head gasket  Tesla Model 3. 205,000 miles. Been to 48 states! Past: A fleet of VW TDIs.... including a V10,a Dieselgate Passat, and 2 ECOdiesels. 2014 Cadillac ELR 2013 Fiat 500E.
|
|
#5
03-19-2010, 10:56 PM
|
||||
|
||||
|
What's the max. no-load RPM of the engine? If it revs to 5200, it's a 3.0L IP.
__________________
 Gone to the dark side - Jeff
|
|
#6
03-20-2010, 12:50 PM
|
|||
|
|||
|
Look at this thread:
'84 380SL OEM Wheels I was looking at an SDL (but didn't buy it) a couple of years ago and did a lot of searching. I made the following notes: avoid engines 603.970 and 603.971. 603.961 is a good long block but may have a bad head. Maybe BC will confirm or correct my understanding.
__________________
Charles 1983 300D, bought new, 215k+ miles, donated to Purple Hearts veterans charity but I have parts for sale: http://www.peachparts.com/shopforum/mercedes-benz-cars-sale/296386-fs-1-owner-83-mb-300d-turbo-rebuild-parts.html
|
|
#7
03-20-2010, 01:22 PM
|
||||
|
||||
|
Quote:
603.96x is a 3.0l engine with a perfect bottom end and a head that is prone to crack when overheated, more easily than other more durable ones. The head can be replaced with a newer-than-14 casting number when it does go, and the higher castings are considered "reliable" by comparison. 603.97x is a 3.5l engine with the same head (except the updated castings) as the 3.0l, but a different bottom end, some fraction of which (I've heard guesses from 1 in 4 to 1 in 2) will at some point prior to 150-200k miles bend a connecting rod, start consuming oil excessively, and require rebuilding or replacing.
__________________
~Michael S.~ Past cars: 1986 300SDL 1987 300SDL 1982 240D 1982 300SD Current: 1987 300SDL
|
 |
| Bookmarks |
|
|
Hybrid Mode
