Can you disable the EGR on a 1991 300D 2.5?
 

Can you disbable the EGR on a 1991 300D 2.5 or will it throw a trouble code??

I would simply remove the vacuum line from the egr valve and plug it. I seriously doubt it would throw a code on a car this early. maybe on the later card with OBD, but even if it does throw a code, who cares? just stare at the light... it becomes your freind in no time at all :cool:

Disconnect it
 

My mate disconnected his egr valve on is 93 300d It wouldn't start and the mechanic actually removed it!, it now runs smother, and appears quicker.
I was speaking to a MB tech last week about it and his comment, 'they cause more problems than they sort'

Desmondo,

Would the car not start in the first place, so the EGR was removed or was it disabled and then the car would not start so it was removed? Does a trouble light now come on to the dash??

Hi CJ

The car would start and after a while die, we had changed fuel and air filters drained the tank (thinking contaminated fuel) it then ran for a short while then died completely...! now 4am so gave up.....
one of the other mechanics took over later in the morning removed the tank and cleaned it! he had no success until he removed the egr valve (seeing the fact that the inlet manifold was restricted by about 50% with crud) It started instantly and is running like a dream with it off... and I mean off, removed , not just the vacuum connection!!
Hence my question the the MB tech. who said that it did no harm if you removed it

ps no warning light, in fact nothing that would make you think there was ever one on.

It is possible for the EGR valve to stick ON, in which case the car runs poorly, particularly at idle. I also had a vehicle in which the controller for the EGR valve failed, causing it to stay continuously on - until disabled.

:)

Ken300D

I have mine disable with a plate. It start up with no problem.

Over the weekend after finished with the glow plugs i cleaned up the crossover tube and the intake manifold. It was full of sticky soot. while the crossover tube was off I could see the smoke coming from the EGR at idle too. I don't know why it is activated at idle. so that's why i disabled it.

Here's a "before" photo of an '87 300D intake at the EGR mixing pipe:

And here's the pipe after I cleaned it up:

Yikes!!!!!

On these photo's of the clogged ERG pipe for that 1987 300D,
what did you expect to find? Ice Cream?

Um, that photo was of the intake charge pipe. The EGR pipe (between exhaust manifold and EGR valve) was about 50% choked off with thick, oily carbon residue. Very nasty. I didn't take a photo of that, but I should have.

:)

I want to stop my EGR from clogging up my intake. Should I make a metal plate and bolt to the EGR OR should I stick a BB in the vacuum line. I have heard responses from people doing both, but being computer controlled I do notwant the car to run bad or throw a code. The car that is in question is a 1991 300D 2.5
Thanks!!!

A "BB" in the line will effectively disable it, but that assumes that the internal spring is keeping the valve closed, and that the valve is seating properly. Most of the time this is sufficient. A more permanent, and foolproof, method is to use a metal plate - but that takes some fabrication and is harder to "un-do" in case of a smog inspection, etc. I'd start with the BB for now!

:)

GSXR-
What would you recomend that I make a plate out of, that will not require going to a machine shop?