EGR valve

[danregs]

now... i've done a search on this and although its not easy to find, there are many, many posts about the EGR system hidden away in past threads.

the reason i'm searching is because i'm considering blocking off the pipe at the N18 but there does not seem to be any conclusion drawn as to whether this is a good idea (i.e. damage to engine or reduced mpg?) or even whether it would yield any noticeable results on my 1.6. (and if any of the other guys are interested then what about results on the 1.8T?)

cheers

 

[sssstew]

im not sure it would give many noticable results dan, ive backed it off fully with vag com and didnt notice anything. I cant see why it would damage your engine (apart from slightly longer warm up times). Some TDI peeps have bunged up the EGR vacuum pipe with a nail and it worked ok so by all means give it a bash.

 

[danregs]

im not sure it would give many noticable results dan, ive backed it off fully with vag com and didnt notice anything. I cant see why it would damage your engine (apart from slightly longer warm up times). Some TDI peeps have bunged up the EGR vacuum pipe with a nail and it worked ok so by all means give it a bash.

ok cheers for that buddy. i was well up for it until i read a post from a while ago on here saying that the EGR system is linked with cylinder cooling? not quite sure how that would be but gave me the goolies!

dont suppose you could post up or email me a pic of which vacuum line it is i need to bung up? i'll prob just stick a nail in it and do it up with a jubilee clip at first to see if i can notice any difference

thanks stew

 

[scrob]

EGR removal has definately been proven to yield gains on other marques, although I've never really heard of any Seat guys doing it. Could be worth investigating?

 

[danregs]

Could be worth investigating?

that what i was thinkin

 

[danregs]

ok i've done a bit of research on this now and it seems that its more likely that you will se noticeable mpg gains than bhp gains. however, some people do say that the top end of the rev range feels more responsive.

the facts of the situation as far as i can see:

1) the egr valve (N18) is never fully opened or fully closed; it only adjusts the extent to which the gases are recirculated.

2) the valve re-circulates LESS exhaust gases with increased vacuum supply. this means that the lighter you are with the throttle, the more exhaust gases are being recirculated (and vice-versa)

3) you can set the exhaust gas recirculation to a MINIMUM at all times by either using VAG-com or by supplying a permanent vacuum to the egr valve.

4) you can eliminate gas reciculation by blocking off the pipe coming away from the exhaust manifold. this can be done by placing a thin metal plate between the pipe flange and the gasket.

5) it will not damage your engine, but will make your car more likely to be emitting gases that are harmful to the environment


well, there you have it. this info is correct to the best of my knowledge, but if anyone has any ammendments to make then please let us know!

 

[t18con]

try vwvortex, there was a major discussion about this 2 days ago by some very knowledgeable people.

 

[danregs]

tried looking for it on vwvortex but theres nothing there

used google to search afterwards and looks like there was a thread but its been deleted?

 

[sssstew]

Dan.

all you posted before sounds spot on to me. Bar the increase in mpg.

 

[Simon L]

try vwvortex, there was a major discussion about this 2 days ago by some very knowledgeable people.

Care to share the link to the thread? I couldnt see it.

 

[Simon L]

Had a look for the thread on vortex with no luck.

So the EGR returns exhaust gas into the inlet pre-turbo?

Surely stopping this will allow new 'fresh' and 'cold' air into the turbo.

 

[t18con]

http://forums.vwvortex.com/zerothread?id=2300509

 

[max_torque]

blocking the EGR valve will harm your fuel economy (introducing exhaust gases (effectively inert due to oxygen already being used up) into the plenum displaces a proportion of the intake charge, so to get the same amount of oxygen into each cylinder you will need to open up the throttle, raising intake manifold pressure for any given load condition. This reduces the engines pumping losses and improves fuel economy) it could also increase your engines NOx emissions on starting (depends how much EGR it runs here and how good you cat is)

What it won't do is increase the engines power or torque, under wide open throttle conditions there is no inlet manifold vaccuum and the system will not be operational anyway.

No long term damage will be caused by blocking the system, although you might get a MIL light to tell you the EGR valve has insufficient flow or similar.

 

[danregs]

ok... see... this is why i wanted to bring it up on here for discussion, cos theres so many different opinions on the disabling of the egr system. after a LOT of research, it seems that the majority of people that seem to know what they are talking about are saying that disabling it is a good idea and it does give the benefits that i listed above (except better mpg, as i wasnt 100% on that one, and stew says its a no, so we'll trust him!).

but you see, i can't discredit the conflicting paragraph that max_torque has just posted because what he says does sound perfectly plausable and i have limited knowledge of the egr system (hence the ongoing research!). its all so confusing!!!!!!

 

[danregs]

oh and correct me if i am wrong, but that vwvortex post was not about the EGR system, it was about secondary air-pump removal???

 

[t18con]

i thought they were same thing, sorry

 

[danregs]

i thought they were same thing, sorry

no problem buddy

it was an interesting debate anyway! i learnt a few things from it

 

[max_torque]

i thought they were same thing, sorry

EGR = Exhaust Gas Recirculation, when you draw in inert (ie no oxygen) exhaust gas into the vacuum of the intake mainfold under part throttle conditions to increase fuel economy under light load cruising conditions and also to limit NOx pollutant formation during combustion

Secondary Air Injection (the air pump thingy!) = You blow fresh air directly into the exhaust manifold as close as you can get to the exhaust valves (either by external pipework on the exhaust manifold, or more often these days via internal passages in the cyclinder head) during a cold engine start (coolant less than approx 50 degC) This effectively oxidises the rich mixture required by the engine to run properly during cold crank and runing. Hence the catalyst is heated quicker, and operates closer to the ideal lambda 1 point so will be much more efficient at limiting cold start exhaust emissions

 

[danregs]

EGR = Exhaust Gas Recirculation, when you draw in inert (ie no oxygen) exhaust gas into the vacuum of the intake mainfold under part throttle conditions to increase fuel economy under light load cruising conditions and also to limit NOx pollutant formation during combustion

Secondary Air Injection (the air pump thingy!) = You blow fresh air directly into the exhaust manifold as close as you can get to the exhaust valves (either by external pipework on the exhaust manifold, or more often these days via internal passages in the cyclinder head) during a cold engine start (coolant less than approx 50 degC) This effectively oxidises the rich mixture required by the engine to run properly during cold crank and runing. Hence the catalyst is heated quicker, and operates closer to the ideal lambda 1 point so will be much more efficient at limiting cold start exhaust emissions

yes and although both these systems have perfectly legitimate operations to perform, many people have removed them and claim to have yielded good results