S320 CDI disconnect EGR vacuum?
- Thread starter Timbob
- Start date
wireman
Senior Member
- Joined
- Sep 20, 2005
- Messages
- 2,632
- Reaction score
- 3
- Location
- lancashire
- Your Mercedes
- nice 201 2.5D 1993 & very nice 129 SL500 1994
I would not recomend it, the system is intended to have it and unpredictable behavior may be the long term result, however pulling the pipe at the valve actuator and plugging it will suffice to disable the EGR valve.
The valve helps keep your emmisions down and economy up, it also is used to purge the cat in your exhaust system. It has no effect on performance (it only operates with light throttle settings) why do you want to remove it?
The valve helps keep your emmisions down and economy up, it also is used to purge the cat in your exhaust system. It has no effect on performance (it only operates with light throttle settings) why do you want to remove it?
television
Always remembered RIP
- Joined
- Mar 14, 2005
- Messages
- 164,073
- Reaction score
- 379
- Age
- 89
- Location
- Daventry
- Your Mercedes
- 2002 SL500, 216 CL500, all fully loaded
Many people take it off and blank it,,you do not need it, better to take the EGR valve out and blank that as it may be stuck partly open
- Thread Starter
- Thread starter
- #4
black smoke at WOT at 1000 - 1500 rpm with little acceleration.
Where is valve actuator sited? Do you have a photo?
I can disconnect at valve actuator and see if it makes a difference before considering long term options
thanks
Tim
Where is valve actuator sited? Do you have a photo?
I can disconnect at valve actuator and see if it makes a difference before considering long term options
thanks
Tim
stumo
Senior Member
- Joined
- Sep 4, 2008
- Messages
- 431
- Reaction score
- 66
- Location
- VIC, Australia
- Your Mercedes
- ML270CDI x3 2002,03,04 | Sprinter 316CDI 2003 LWB
Yes I was also thinking about blocking mine. The old way to do it was to shove a ball bearing up the vacuum pipe, that way it is invisible.
Having said that, I also read that these days part of the emissions compliance is that the ECU in the car must periodically test that the EGR system is working, and must throw a CEL if it is found to be not working. It can do this for example by fully openeing the EGR valve, then checking that MAF decreases at the same time.
It is important to note (as television eluded to above) EGR on a diesel engine is kind of a bodge to reduce NOx emissions. It does nothing good for your diesel engine and will reduce fuel economy over time because the inlet tracts etc become clogged and the engine prematurely wears due to ingestion of particulates. The only "good" thing it does is slightly lower combustion temps, but that is just a way of reducing NOx, not really any better for the engine.
EGR on a petrol engine is an entirely different story. Aside from emissions, it also serves to dlute the freash air charge, so that the engine can run lean without actually running lean. Which is good for fuel economy.
So in summary
EGR+Diesel=bad
EGR+Petrol=good
Having said that, I also read that these days part of the emissions compliance is that the ECU in the car must periodically test that the EGR system is working, and must throw a CEL if it is found to be not working. It can do this for example by fully openeing the EGR valve, then checking that MAF decreases at the same time.
It is important to note (as television eluded to above) EGR on a diesel engine is kind of a bodge to reduce NOx emissions. It does nothing good for your diesel engine and will reduce fuel economy over time because the inlet tracts etc become clogged and the engine prematurely wears due to ingestion of particulates. The only "good" thing it does is slightly lower combustion temps, but that is just a way of reducing NOx, not really any better for the engine.
EGR on a petrol engine is an entirely different story. Aside from emissions, it also serves to dlute the freash air charge, so that the engine can run lean without actually running lean. Which is good for fuel economy.
So in summary
EGR+Diesel=bad
EGR+Petrol=good
Last edited:
stumo
Senior Member
- Joined
- Sep 4, 2008
- Messages
- 431
- Reaction score
- 66
- Location
- VIC, Australia
- Your Mercedes
- ML270CDI x3 2002,03,04 | Sprinter 316CDI 2003 LWB
Disconecting it probably wont help you there since it should be fully closed under WOT anyway. You might have to take a look at the actual valve to make sure it is closing, since they can fail stuck open.
stumo
Senior Member
- Joined
- Sep 4, 2008
- Messages
- 431
- Reaction score
- 66
- Location
- VIC, Australia
- Your Mercedes
- ML270CDI x3 2002,03,04 | Sprinter 316CDI 2003 LWB
I just replied to your other thread on where the EGR valve itself is...
http://forums.mercedesclub.org.uk/showthread.php?t=42118
It will be a prick to get at it though, good luck. Once you see it you should be able to trace what drives it, though it looks to me like it has an electrical actuator at the valve itself? That would indeed be odd. Of course this is assuming I have found the right diagram for your car!
s class 320 cdi
suspected egr problems etc.limp mode etc.P1470 code in ecu memery.spent a lot of time and money to get to the botom of this.did with great sucsess.if you need any tips
then pls e mail me!!!!!!!!!
neilhyre@hotmail.com
Dont get suck in to espensive (so call dianogist work when they are guessing!)
suspected egr problems etc.limp mode etc.P1470 code in ecu memery.spent a lot of time and money to get to the botom of this.did with great sucsess.if you need any tips
then pls e mail me!!!!!!!!!
neilhyre@hotmail.com
Dont get suck in to espensive (so call dianogist work when they are guessing!)
