Does 1979 300SD Turbo Have a Rack Damper?? - PeachParts Mercedes-Benz Forum

Dionysius · #1 03-17-2009, 10:38 PM

I looked on back of IP but do not see a Rack Damper as described in this site.

Please tell me if it has one for that year.
If not then why not??
When were they introduced??

#2 03-18-2009, 12:03 AM

In W126 and turbo W123 models.

toomany MBZ · #3 03-18-2009, 03:34 AM

I believe all turbos of the era have one, please look again, and post pics if you can.
By your post you should know where it is, but if not, it's low on the back of the injection pump, just in front of the oil filter canister.

nhdoc · #4 03-18-2009, 07:11 AM

The '79 has the manual idle control knob on the dash...not sure but I don't think it had the rack damper.

rs899 · #5 03-18-2009, 07:20 AM

My '80 W116 300SD does not have a rack damper.

bgkast · #6 03-18-2009, 02:17 PM

My '80 300SD engine has one.

Dionysius · #7 03-18-2009, 02:54 PM

The last two responses conflict. Was a Rack Damper introduced in the 1980 Model year perhaps??

nhdoc · #8 03-18-2009, 03:05 PM

My understanding was that if the cars had the adjusting knob on the dash that they didn't have the rack damper...am I correct about that or not? My '79 had the knob, I know that.

Dionysius · #9 03-18-2009, 03:16 PM

Here is my confusion on your reply...NHDoc:

The Rack Damper is there to remove a resonance set up from fuel injection that makes a rough idle.

The knob is only setting the idle rpm. Just a throttle stop.

Two different functions. Non-overlapping.

Someone please jump in......

nhdoc · #10 03-18-2009, 03:27 PM

Quote:

Originally Posted by Dionysius

Here is my confusion on your reply...NHDoc:

The Rack Damper is there to remove a resonance set up from fuel injection that makes a rough idle.

The knob is only setting the idle rpm. Just a throttle stop.

Two different functions. Non-overlapping.

Someone please jump in......

I know that they perform separate functions but I thought (and I might be wrong) that the rack damper was also part of the idle control "upgrade" done when idle control went from a manual (knob on the dash) adjustment to automatic. This was around 1980 IIRC. So those engines with the auto idle control (no knob) would have the damper while those without the knob would. Like I said, I could be wrong about all of this as I have not owned enough of them to conclude this.

rs899 · #11 03-18-2009, 03:58 PM

My 1980 W116 (a California car) does not have either a rack damper or manual idle control, FWIW.