I've heard of people blocking off the EGR to get a performance gain. I can see why, theoretically, can't be good for performance having foul, hot gas spewing back into the intake. I tried disconnecting the EGR valve solenoid (the hoses, not hte valve itself) and I SWEAR it's quicker. Am I imagining things? can it cause any damage? it's a 5 cylinder 2.5 TDI.
yes there must be some gains, I've recently done mine on 130 pd daily. on a 240 mile run I do regularly i saved about 5 litters ( guessing of guage reading), while doing bit more than eco run It also moved bit better i think, but that could be me wanting to think its quicker!! I'm not familiar with your engine but its a case of loosening pipe that feed EGR valve, copying gasket on cooler side (inlet end) in aluminium or steel to make blanking plate, original gasket & silicone sealer sandwiched with original pipe job done
Easy-as to make on a 1.9 - click No damage as such but there was some mention of the tickover being rougher in an article I read. Frankly when I'm starting with a bag of diesel nails, that's splitting hairs tbh.
why bother blanking it off? I've just disabled the control solenoid so it's shut all the time. same thing no?
Some management systems measure the degree the valve is open, it constantly measures the amount the valve is open/closed so it can regulate the position more accurately, the later the vehicle the less chance you have of disabling the ERG valve without flagging up a fault code and the ECU altering the engine map, which drops the performance. Easiest way is to blank off the pipes, your 2.5 TDi is a simple design and disabled easily unless the valve sticks open slightly
oooorrrr turn it off with vag com.. what you REALLY need to do is put a catch can on the engine breather, as this will see better gains, and stop the intercooler being coated in oil, again reducing the efficency and power. as I under stand it the egr only works on idle and part throttle crusing, the idea being that a small percentage of the hot exhaust gasses go back in to the combustion chamber, thus already raising the temp of the gas in there before its com pressed, this allows a smaller amount of fuel to be injected and ignite easier. when you boot it the egr shuts to give a purer air supply. the recirc of the exhaust gasses also helps in cold weather to heat the engine a little quicker, and to make the idle smoother. if you de-gunk the egr valve and the inlet manifold (if needed) then fit a catch can to the engine breather, or vent to atmos , and clean out the intercooler and boost pipes to remove the oil, you will get bigger gains. and if theres no oil vapour the inlet cant gum up.
the egr is closed at full throttle. it only actuates at low revs, low rpm. if there was any boost, it would be acting like a wastegate blowing charge stragith out the exhaust. they get blanked because they can jam and when they do work propely they bring soot and crap
the EGR aldo helps to cool on lean burn part throttle. ie when crusing, yes it does reduce the theroetical power slightly but it also has benefits. and it reduces the NOX emissions. like I said above remove the oil from the inlet and you will get more benefits! oil reduces the rating of the fuel mix, and therefore lowers power per unit.
mine used to sometime stick open on my 2.5 , but if you have the login code you can disable it in vag-com
if you dont remove the oil from the inlet tract it will prob need cleaning a little sooner, but it still the best idea for everyday use.
To clean out my 1Z Passat, it took me a whole day - the inlet ports are out of the way, and it was all done with a mirror. The inlet itself was gunged up, but of course that can be done off car. I wouldn't want to create work, so it's staying blocked off for now. Well worth changing any new nuts to replace any rusted ones on the EGR feed pipe, where it attaches to the exhaust manifold. I had to Dremel one off, to avoid risking a snapped stud. It took ages, so when you get a new purchase, get in there quick to avoid seize-ups later.
Chris, fit a catch can to the oil breather and you will find there are sod all probs after that, plus give the car some stick once every few weeks to clear any soot out that may build up (but it should be sod all as 1 the egr works on part throttle....and at part throttle there is complete combustion due to an excess of air...and 2 with no oil valour theres nothing wet to make any soot or bunt crud stick)
I've seen the catch tank idea - there was an article in VW Driver, but I've put it down somewhere. Stick? It gets it all the time
yes it was the Mahn Filters provent in driver mag. designed for turbo diesel application i could do with one myself, or something similar
almost any measure of EGR will actually cool the peak temps in the combustion chamber. yes, the additional heat of the EGR gas will increase the net charge of air in the cylinder but as the EGR is an inert gas less fuel is needed and in-cylinder temps are cooler = lower exhaust gas temps. I don't know about the strategy/FIE or durability sign-off on your car Paul but blanking the EGR valve will have teh following generalised effects: - the performance increase you are subjectively feeling is that generally when you tip-in hard and the Tq request to the PCM is sufficient to close the EGR valve then there is a period as the valve is closing but the vanes (I assume VGT?) are closing to increase boost. Dpeending on the interaction between these two systems you can get a lag for 2 reasons - firstly the EGR system is a volume of air which has to be pressurised, secondly you can get a slug of EGR thrugh the valve before it closes - both of these depend upon the engine pressure ratio. - as you are no longer running EGR the in-cylinder and exhaust temps are goign to be higher within the part-load region where you used to run EGR. This could have a long term cycle fatigue effect on injectors, turbine (wheel and VGT rack) and anything else subjected to these higher temps downstream of the turbine. You could also run into higher temps at idle/low engine speeds and therefore require additional heat rejection from the rad etc. - although this probably won't be a problem unless you're planning on hot climate or high altitude/ or heavy towing work. All in all, yes it will have an effect, there's always some sort of trade off - in this situation it looks like a trade off for long term component durability - but thats' what we all do when we liek to mess with our engines anyway - it's a small but calculated risk tuning boxes and TDI remaps though, I wouldn't touch them with yours
guys, i am thinking of doing the catch tank thingy(what M7R was talkiing about), where do i start. i have already blanked of my egr valve but am worried about the oil going to the intercooler and want to stop tis happening. any pics out there to guide me? i have the aaz engine with added intercooler from a tdi but wanna change that to a sharan one as it will fit perectly into the mk3 front bumper if i remove the grills at the bottom!
