J.K.jr.bad.
Guest
If I'm right EGR lets gases recirculate only when engine runs idle or on low power. Recirculating gases lets them burn more then one time and in this way they gets cleaner.
kenny629
Guest
ill be taking my cat off and putting a blanking plate in the egr i think, see how that goes, and giving my inlet system a damn good clean as there could be loads of gunk in it now (its covered 75000k)
Mine has covered 120k and did the egr blaking mod 20k ago. Mapped 7k ago to 180 with the magnex and the green cotton filter and the engine is better than ever. Sod it if the cat is filling up with soot it seems most of it comes out the back anyway!
Glynn
it is only a small diameter pipe going into the egr. Is that that the one to block? if it is exhaust gas why doesnt it melt the pipe? sorry for being thick.
Surely that small amount of gas going through the exhaust extra when you block the egr off would not cause the cat to become blocked more quickly.
Surely that small amount of gas going through the exhaust extra when you block the egr off would not cause the cat to become blocked more quickly.
ucchocky: the small-diameter pipe going into the EGR valve is a vacuum pipe: the EGR valve is vacuum-actuated, and the vacuum is controlled by a separate valve on the engine bay bulkhead, the N18 valve, which is in turn controlled by the ECU. My guess is that it's cheaper and more reliable to use vacuum to control hot bits than it is to put in an electrical bit that can work at high temperatures. The wastegate/vane control on the turbo is also worked by vacuum, controlled by the N75 valve.
EGR recirculates exhaust gas to the inlet charge to reduce the oxygen content in conditions where the engine is working hard and combustion temperatures get high enough to burn nitrogen to NOx. The whole point of using exhaust gas is that it is an easy source of inert gas to dilute the oxygen - the engine designers fervently hope that there is no oxygen left at all, so it can't burn again. The aim is to meet the legal environmental requirement for low NOx emission. EGR actually increases particulate (i.e. soot) and CO emission while it is in operation - that's the reason you see a puff of smoke when you're accelerating to join the motorway, for instance. So the designers have to balance this against the reduction in NOx.
The only negative consequence of shutting off EGR is an increase in NOx emissions. CO and particulate emissions will improve, and your catalyst will have less work to do and will last longer.
NOx is demonised as a smog precursor, but having looked at the evidence (and there are a lot of environmentalists who share these doubts) I think that targetting NOx in isolation is pointless, as it is the interaction of NOx with other smog factors, e.g. unburned hydrocarbons and particulates that causes smog, and reducing one while increasing the other is no help at all.
My TDI 110 does not complain when I defeat the EGR by disconnecting the electrical connector from the N18 valve. I think later revisions of ECU perform a vacuum check to see if all the bits are working, but I could be wrong.
EGR recirculates exhaust gas to the inlet charge to reduce the oxygen content in conditions where the engine is working hard and combustion temperatures get high enough to burn nitrogen to NOx. The whole point of using exhaust gas is that it is an easy source of inert gas to dilute the oxygen - the engine designers fervently hope that there is no oxygen left at all, so it can't burn again. The aim is to meet the legal environmental requirement for low NOx emission. EGR actually increases particulate (i.e. soot) and CO emission while it is in operation - that's the reason you see a puff of smoke when you're accelerating to join the motorway, for instance. So the designers have to balance this against the reduction in NOx.
The only negative consequence of shutting off EGR is an increase in NOx emissions. CO and particulate emissions will improve, and your catalyst will have less work to do and will last longer.
NOx is demonised as a smog precursor, but having looked at the evidence (and there are a lot of environmentalists who share these doubts) I think that targetting NOx in isolation is pointless, as it is the interaction of NOx with other smog factors, e.g. unburned hydrocarbons and particulates that causes smog, and reducing one while increasing the other is no help at all.
My TDI 110 does not complain when I defeat the EGR by disconnecting the electrical connector from the N18 valve. I think later revisions of ECU perform a vacuum check to see if all the bits are working, but I could be wrong.
Muttley hit the nail on the head there! I have taken the vacuum pipe off the EGR and blocked it with an ally rod I turned up specilly! MPG is slightly better and the engine seems more responcive, but in cold weather the engine take a few more mile to warm up!
just a quickie,what do you do with the egr end?leave that open? i was just about to block off the pipe then though "what about the t'other end?)
when you've blocked the rubber vac' pipe to the top of the egr push the pipe back on the egr stub, nice and neatjust a quickie,what do you do with the egr end?leave that open? i was just about to block off the pipe then though "what about the t'other end?)
there seems some confusion with others, about the "blanking plate" it's only needed if you want to restrict the exhaust gas flow (has a hole in it) or to blank the gas flow or if you remove the flex pipe at the bottom of the egr you'll need 2 plates and gaskets
I was getting a slight hiccup from the engine around 2100-2000rpm while cruising, I have since blocked the top EGR pipe with a golf tee of all things and the hiccup has not occurred since. Also it does seem to be run smoother.
Now I dont know if I should now replaced the EGR to fix for good or change to the Allard replacement section (will this cause a check light?) - or maybe turn it down in vagcom ... what would you guys suggest?
Engine is a 150PD 2002 - ARL I think it is.
Now I dont know if I should now replaced the EGR to fix for good or change to the Allard replacement section (will this cause a check light?) - or maybe turn it down in vagcom ... what would you guys suggest?
Engine is a 150PD 2002 - ARL I think it is.
I used the Allard EGR replacement pipe, I had no problems, no lights nothing. Took about ten minutes to fit, comes with blanking plate, gasket everything you need.
However one thing to note is that as standard it has a boost gauge pipe, so you don't have a boost gauge ask for one to be made with the pipe or you'll have a problem.
However one thing to note is that as standard it has a boost gauge pipe, so you don't have a boost gauge ask for one to be made with the pipe or you'll have a problem.
I guess it's about the 100th time but it's worth to point out that the allard race pipe removes the anti shudder valve,,, if you can live with the shudder on turn-off it'll be ok, if you can't, don't use this mod.
On the PD engines, as I got it, this seems to be not an issue as devonutopia can confirm. On my 110, when I broke the ASV nipple the engine was shakin BADLY on turn off,,,
On the PD engines, as I got it, this seems to be not an issue as devonutopia can confirm. On my 110, when I broke the ASV nipple the engine was shakin BADLY on turn off,,,
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