1982 300D, what's this part? - PeachParts Mercedes-Benz Forum

300DPETE · #1 11-02-2005, 12:31 AM

1982 300D

Hi, everyone

What is the part with the two vacuum lines coming out of it in the picture below? It's to the right of the temperature swith.

I'm suspicious of it causing my vacuum leak. I thought I had a leak in my door/trunk/reservoir system, but that checked out okay. The vacuum pump tests out okay, as does the brake booster, as does the vacuum shutoff valve, as does the EGR valve. Not many parts left to check, and the rubber connections on this piece pictured have many tiny cracks on the surface.

Thanks,
Pete.

pawoSD · #2 11-02-2005, 12:42 AM

It is a temperature activated vacuum valve designed to open and close the vacuum to the EGR valve depending on engine temperature.

300DPETE · #3 11-02-2005, 12:44 AM

Cool, thanks!

Anybody ever have it end up beeing the source of a vacuum leak?

Thanks,

Pete.

#4 11-02-2005, 01:42 AM

My vacuum line somehow got a BB lodged in the tube.

I still can't figure out how to get it out of there...

Wes Bender · #5 11-02-2005, 09:45 AM

That "bb in the tube" thing has reached epidemic proportions. I've got one too.

tangofox007 · #6 11-02-2005, 11:28 AM

Quote:

Originally Posted by 300DPETE

1982 300D

Hi, everyone

What is the part with the two vacuum lines coming out of it in the picture below? It's to the right of the temperature swith.

I'm suspicious of it causing my vacuum leak.

If you have a vacuum leak associated with the EGR system, the most likely culprits are the valves under the black cover on the top of the valve cover. You might try disconnecting and plugging the vacuum line that supplies vacuum to those valves. (For troubleshooting purposes only, off course, as this will disable the EGR valve.)
A lot of folks block the vacuum line at the EGR valve, but this leaves the control valves in the loop to cause problems when they leak. So if you want to disable your EGR valve for those off-road excursions, plugging the vacuum line upstream of the 3/2 way valves might make more sense, at least on this model.

pawoSD · #7 11-02-2005, 12:25 PM

Quote:

Originally Posted by Wes Bender

That "bb in the tube" thing has reached epidemic proportions. I've got one too.

My entire vac tube from the airbox on the valve cover to that temp valve thing is gone, and a golf tee is stuck into the hole in the airbox.

The tab is broken off on the temp valve anyways, can't even connect a line to it anymore. There is still one from it to the EGR tho, not like it does anything.

In michigan you can drive anything you want, as unsafe as you want, and as polluting/dirty as you want. No smog or safety checks here!

300DPETE · #8 11-02-2005, 01:19 PM

I tested the EGR valve itself separately and it did hold vacuum (no, I don't want to disable it). So, I'm assuming I need to do something wtih this EGR/temperature controller valve. If I'm lucky, it's just the old rubber connections.

Pete.

#9 11-02-2005, 03:56 PM

Quote:

Originally Posted by 300DPETE

I tested the EGR valve itself separately and it did hold vacuum (no, I don't want to disable it). So, I'm assuming I need to do something wtih this EGR/temperature controller valve. If I'm lucky, it's just the old rubber connections.

Pete.

Curious as to why you don't wish to disable (I mean test the inoperability) the EGR?

300DPETE · #10 11-02-2005, 04:09 PM

I don't mind the loss of power. I'm trying to reduce emissions as much as possible (I did a VO conversion on it with a Frybrid kit, pictures within the month).

Besides, it's not like it drives like a dog. It runs quite nicely.

Pete.

d.delano · #11 11-02-2005, 06:48 PM

Quote:

Originally Posted by Wes Bender

That "bb in the tube" thing has reached epidemic proportions. I've got one too.

A wayward hooligan stole my EGR.

sailor15015 · #12 11-02-2005, 07:45 PM

Quote:

Originally Posted by d.delano

A wayward hooligan stole my EGR.

That must be the same hooligan who snuck under my hood last night and put a cap on the line going to my EGR. Some people.

#13 11-03-2005, 02:10 AM

Quote:

Originally Posted by 300DPETE

I don't mind the loss of power. I'm trying to reduce emissions as much as possible (I did a VO conversion on it with a Frybrid kit, pictures within the month).

Besides, it's not like it drives like a dog. It runs quite nicely.

Pete.

Its not so much the loss of power as it is black gunky goo (others will disagree but whatever) that gets basically dumped right into cylinder 1.

I'd try it disabled and not...and see what you like best. You might actually be suprised...(on an old car)

300DPETE · #14 11-03-2005, 11:55 AM

I did notice a bit of black goo on the tip of my #1 glowplug when I took it out the other day.

What exactly does the EGR do anyways. Reduce CO emissions? Is it something else?

Thanks,

Pete.

#15 11-03-2005, 12:35 PM

Quote:

Originally Posted by 300DPETE

I did notice a bit of black goo on the tip of my #1 glowplug when I took it out the other day.

What exactly does the EGR do anyways. Reduce CO emissions? Is it something else?

Thanks,

Pete.

In theroy (and probably when the car was newer) it injected some burnt gases to cool the fuel burn and thus reduce NOx emissions. (the only one that diesels still have compared to gassers).

Now when the car is older, all this sooty black goo has entered the intake and has made a huge mess. Not to mention the fact that number 1 cylinder is getting a healthy dose of carbon goo (and I would imagine that it promotes a larger amount of wear and tear)

The EGR wouldn't be such a bad idea if it didn't heavily contaminate the intake...unfortunately thats the basis upon its operation. You can view many other threads regarding pros/cons if you do some searches...I just gave you the skinney

I disabled and removed mine (along with many others) becuase after I saw that goo that nearly plugged a 1/2 inch hole....I didn't like the fact that my engine was running on sludge...