'85 CA car EGR question - PeachParts Mercedes-Benz Forum

Maroon 300D · #1 06-21-2006, 08:35 PM

The vac line to my EGR was hooked up, but it appears the valve is not working. It doesn't hold any vacuum when tested and I can't see anything moving in that little 'window' when I give it vac.

I've done some research but most of that pertains to the old vac system with the stuff on the valve cover.

My question: Can I just plug the line to the EGR and not have to worry about it? Or will leaving the EGR in place have some negative effect if I remove the vac line to it? I'm thinking it would be fine but I'm not totally clear on this.

Oh, and another question: Is there also a line to the EGR from some sort of temperature sensor?

As usual, any help will be greatly appreciated. Thanks!

rwthomas1 · #2 06-21-2006, 08:57 PM

If the EGR is truely inoperative then plugging the line with a BB will just give you peace of mind. The only possiblility, and its a small possibility, is the EGR is stuck partially open and constantly backfeeding exhaust into the intake. The easy way to fix this is to remove the EGR and make a thin plate out of aluminium using the EGR gasket as a template. This plate has no hole in it to allow gasses through and simply installs underneath the EGR valve to totally and completely block off the opening. Sneaky, cheap and effective.

You likely have an ARV valve on your turbo as well. This can be disabled easily as well and your highway throttle response will improve. Do a search on ARV. RT

Maroon 300D · #3 06-21-2006, 09:13 PM

Thanks! That's good info.

It took me a while to find this for some reason, but this thread seems pretty relevent to my questions, also.

EGR Disabling, Good Idea?

Guess I'd better get that busted valve out of there when I get a chance.

Brian Carlton · #4 06-21-2006, 09:30 PM

Quote:

Originally Posted by Maroon 300D

Thanks! That's good info.

It took me a while to find this for some reason, but this thread seems pretty relevent to my questions, also.

EGR Disabling, Good Idea?

Guess I'd better get that busted valve out of there when I get a chance.

EGR blocking plate kit

Maroon 300D · #5 06-21-2006, 09:35 PM

Yes I'd seen that, Brian, and I'm interested. When will they be produced again?

Maroon 300D · #6 06-22-2006, 12:02 AM

Well I've disconnected the vacuum line to the EGR and I also decided to play around with the nut that sits atop the EGR housing. I noticed that when I tightened the nut, the valve seemed to hold vacuum a little longer and when I loosened it, it didn't hold any at all. Even when it was tight the vac diminished very rapidly.

Unfortunately, I broke the screw while attempting to get the nut back on. But it doesn't seem to make any difference in terms of driving. I just drove about 6 miles and everything seemed normal.

From what I've read, I would be suffering from low power at low rpm's and I would probably be smoking if my EGR valve was stuck partially open. That's not happening.

Is there any way of knowing whether it's opened or closed without taking it apart? Getting all those bolts off seems kind of troublesome and time consuming if the valve is already closed anyway. If it's open I suppose I would have to do it (or would I?)...otherwise I would probably wait on it until I have more time or assistance.

Other questions I have include: how does this thing function, anyway? I suppose exhaust fumes don't recirculate to the engine if it's closed, but why is it better to have it stuck open than partially open?

Thanks.

Brian Carlton · #7 06-22-2006, 12:18 AM

Quote:

Originally Posted by Maroon 300D

Yes I'd seen that, Brian, and I'm interested. When will they be produced again?

I've got plenty of them.

Just shoot me an e-mail and I'll give you the payment details.

Jeremy5848 · #8 06-22-2006, 07:46 PM

After reading all of the EGR threads, I went out into the garage and looked at my 300D. I wanted to see if I could figure out (from the diagrams) which piece was where. When I got to the EGR valve, I pulled off the vacuum line so I could test the valve (it works, I learned) and what to my surprise did I find: some PO had stuck a BB in the line!

Somehow, I feel cheated.