Hey,

I recently drove a 1995 S350D and was amazed at how quiet the engine was at idle. I previously owned a 87 300 SDL and a 80 300D, which are rattle very loudly at idle.

What did MB do to quiet the 350 down? Can any of that be applied to an older diesel to make it quieter?

Thanks...


-m

__________________
Now:
2018 Tesla Model X
1999 S500 Grand Edition 164k
1992 300D 2.5 Turbo 287k
2005 E320 4MATIC wagon
1991 Alfa Romeo 164L 99k (sleeping for a while)

Then: 96 Lincoln TC, 93 Lincoln TC, 87 560 SEL, 87 300 SDL, 80 300D, 89 560 SEC

The newer diesels are getting more and more quiet. This is due to the basic engine design. There is nothing you can do to transfer this to your older diesels. I had a '96 E300d with the same basic engine, and I don't know how many people who rode with me were amazed to learn that it was a diesel.

For a die-hard diesel fan like myself this is a down side. What you call "noise" is music to my ears. I love the sound of a properly running 616 or 617 diesel.

Have a great day,

Oh, I'm totally with you on the noise part. I loved my 87 300 SDL, rattling and clanking like crazy. It really sounded like a woodchipper about to spew the engine out the grille.

The wife, natually, doesn't really enjoy the sound as much as I do. That's partially preventing us from getting another diesel at this point. The VW Passats (1996,1997 type vintage) are fairly quiet, but you can still tell it's a D.

Anyway, thanks.

-m

__________________
Now:
2018 Tesla Model X
1999 S500 Grand Edition 164k
1992 300D 2.5 Turbo 287k
2005 E320 4MATIC wagon
1991 Alfa Romeo 164L 99k (sleeping for a while)

Then: 96 Lincoln TC, 93 Lincoln TC, 87 560 SEL, 87 300 SDL, 80 300D, 89 560 SEC

A significant amount of the diesel noise (I prefer the term "purr") comes from the direct injection system. Newer diesel engines use a two-stage injection (a small primary pulse of fuel followed by the "real" pulse of fuel injection) to achieve a much quieter sound. Our New Beetle TDI was almost as quiet as a gasoline car when it was brand new, but after the engine got broken in it got a little noisier. It's still silent compared to the Mercedes 616 and 617 engines.

- Nathan
'83 240D "Steiner"
'00 New Beetle TDI

Thanks for the correction of terms. Purr is definitely the correct term.

Have a great day,

Yeah they purrr like cats at idle, but roar like lions when the turbo spools up.

__________________
1999 MB SL500 (110,000 mi)
2004 Volvo V70 2.5T (220,000 mi)
2014 Tesla Model S 85 (136,000 mi)
MBCA member

the 350SD, 350SDL, S350, S300 and 92+ 300SD where all LEMONS. This engine was known to have catastrophic failure before 100K miles like burning 1qt of oil every 100 miles, throwing rods, pistons out of round. A complete nightmare. Stay away from them at all costs. I hear if the engine has been rebuilt they are OK but I would not take my chances with it.

there is good reason to take heed on this ...there have been many failures of engines in this 3.5 litre diesel...mine failed at 103K.....but there are two curious aspects of this engine....some people have gone 200K plus with no problems(?)
and the replacement engine is not as quiet as the original was...but still much quieter than the older cars
The internal parts ,I have heard ,are much beffier than the originals were...but I still wonder why the new engine is louder?


Warren
1992 300SD 120K
Columbus Ohio
turner@greif.com