I was told the only thing I need to do to swap a 3L for a 3.5L is change the motor mounts. Is this correct?

In what car?

__________________
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.

a 3L six from a 1987 300 sdl into a 91 350 sdl

Been there, done that. Iirc you will need to use oil pan from
350sdl too. Don't remember reason though.

__________________
Jim

The 3.5L engine's oil pan doesn't have the little side access cover.

Be sure to nab the AC compressor, bracket, and alternator off of the 3.5 as they are different. You could also move over the 3.5's water pump pulley as it's smaller (to spin the fan faster).

-J

__________________
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.

Ditto on Compu85. Done this exact swap many times. The oil pan from the 87 with the side sump cover fits fine on the 91. If the AC system is sealed and working on the 91, just tie the compressor aside, and move the bracket over and leave the system sealed. One is a 10P15C, and one is a 10P17C, dont recall which is which. You can tie the PS aside as well and leave it sealed.

__________________
1987 300SDL #1, 1987 300SDL #2, 1980 240D, 1982 300SD, 1994 S350, 1990 350SDL, 1991 350SD, 1985 300D, 2005 E320CDI

Gone, but not forgotten: 1981 300SD, 1982 300SD, 1987 300SDL, 1983 300TD, 1980 300CD, 1981 300SD #2, 1987 300D, 1987 300TDT, 1980 300D

And I used the same mounts as well with no issues.

__________________
1987 300SDL #1, 1987 300SDL #2, 1980 240D, 1982 300SD, 1994 S350, 1990 350SDL, 1991 350SD, 1985 300D, 2005 E320CDI

Gone, but not forgotten: 1981 300SD, 1982 300SD, 1987 300SDL, 1983 300TD, 1980 300CD, 1981 300SD #2, 1987 300D, 1987 300TDT, 1980 300D

The 350 has the larger 10P17C compressor (and a parallel flow condenser!).

-J

__________________
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.

Hmm, I didn't realize they used a PF condenser. Maybe that's where my blockage is, haha.

__________________
1987 300SDL #1, 1987 300SDL #2, 1980 240D, 1982 300SD, 1994 S350, 1990 350SDL, 1991 350SD, 1985 300D, 2005 E320CDI

Gone, but not forgotten: 1981 300SD, 1982 300SD, 1987 300SDL, 1983 300TD, 1980 300CD, 1981 300SD #2, 1987 300D, 1987 300TDT, 1980 300D

Thanks much for all the input. I will be interested to see the difference in the two engines. I own a 90 350 SDL with 265k on it and running strong. This 91 was an unintended purchase. I saw it a a used car dealer and stopped to see what it was. Interior was even better than mine but needs paint job. 17"AMG wheels with good Michelin tires. I stuck my finger in the water reservoir and came up with a finger full of oil. Ended up paying $1500 for it as a parts car. My only quandary is what to do with two of these.

It's a slippery slope... One day you wake up, and you have 19 MB diesels... I'm STILL selling off cars. It's great fun buying them, not so fun selling them. But, I will say, you have the perfectly outfitted shop to do that type of work. First class! I'd love to turn a wrench or two in there.

__________________
1987 300SDL #1, 1987 300SDL #2, 1980 240D, 1982 300SD, 1994 S350, 1990 350SDL, 1991 350SD, 1985 300D, 2005 E320CDI

Gone, but not forgotten: 1981 300SD, 1982 300SD, 1987 300SDL, 1983 300TD, 1980 300CD, 1981 300SD #2, 1987 300D, 1987 300TDT, 1980 300D

Going in for a total hip replacement 8/5 which will slow me down for a while. If your ever in this area again give me a call Al

Oil in the cooling system is not the end of the world. Since this is a project car, replace the head gasket and see if oil consumption and exhaust smoke is tolerable. Mabye it can remain a 3.5.

Are there markings to suggest the block has been replaced such as a head casting later than -17-? Note the tag on the passenger side bell housing flange for a dealer replacement .970 -



Sixto
87 300D

Hi all,

Just finished a swap from an OM603.97 ( rod bender) back to a OM603.96. Only replaced the block. Head, IP, is from the original .97. Hving timing issues. Can I use the pump from the original car or I need to find an old Injection pump as well ? Any help would be greatly appreciated.

Thank you all !

Mine had oil in the coolant. Probably the best hg failure you can have, fwiw.

__________________
Current Diesels:
1981 240D (73K)
1982 300CD (169k)
1985 190D (169k)
1991 350SD (113k)
1991 350SD (206k)
1991 300D (228k)
1993 300SD (291k)
1993 300D 2.5T (338k)
1996 Dodge Ram CTD (442k)
1996 Dodge Ram CTD (265k)

Past Diesels:
1983 300D (228K)
1985 300D (233K)