What is this part? 82 300SD Engine
 

Juse below the air cleaner to the lower right and close to the valve cover. Am I also missing a vacuum hose on this part?

http://s12.postimg.org/4q1zbw51p/foto55.jpg

That is the EGR valve (exhaust gas recirculation valve). It basically recirculates exhaust into the intake for emissions purposes, and yes, it does need a vacuum line. Your car actually does not have the stock accelerator linkage -- the stock linkage would look like the one below, with the black box there being for the EGR.

I would leave it like it is. There is an almost universal consensus that the EGR is no good for a diesel because it recirculates all the soot from diesel combustion through the engine again.

EGR
 

It's the EGR valve and yes in theory it is supposed to have a vacuum connection. However, people sometimes *modify* the EGR to gain a bit of performance, so it may not be an issue.

Please take a photo or two of how the vacuum lines are hooked up on the driver's side of the engine compartment (to show how the various vacuum lines and connectors are set up). There should be one open vacuum bleed line, running from the side of the yellow plastic valve assembly on top of the injection pump. Other than that, there should be no open vacuum lines or connectors.

People imagine all sorts of evil behavior associated with the EGR and think they've made an "improvement" if they disconnect it. Unless you can retune the whole system there's not much to be gained by pulling the line off of it.

Dan

Yes, egr valve. I have mine disabled, hopefully.

You're missing the thermo switch too, a bolt has taken its place.

The part to the left and below the EGR is the ARV Valve on the Turbo. It has it`s Vac line removed too.

The EGR probably wasn`t working anyway. the hole under it in the intake Manifold was probably plugged tight with oil soot mixture that = Goo.
Every one I have removed in PNP and all were higher milage vehicles (200K or higher) and all were plugged up.

The inside of the manifold is probably thickly coated with the Goo.


Charlie

I disconnected mine about 9 years ago. :D

Removed it entirely and put in a block-off plate on another one....