Just wondering if anyone has some first hand experience with blanking the EGR in situ. Had a read on the interwebs and havent really been able to find a definitive answer. Im halfway through a plenum pull and was just wondering if it is possible to blank the EGR by removing the EGR vac line and plug to the solenoid and possible fitting some blanking plates between the EGR feed lines and the bottom of the plenum. Will this be ok, will the EGR valve be inoperative and will there be any fault codes shown on the dash? Thanks in advance.
EGR doesn't throw codes. If you have the blanking kit just cut all the EGR hard lines with a hacksaw. Remove the fittings from the plenum and passenger side exhaust manifold and blank those off with the items from the kit. Can be done in situ.
i have blanking plates for the plenum but not the plug for the passenger side exhaust manifold. Im also unable to get the feed pipe loose from the exhaust manifold, pretty much welded in there. Is it possible to bypass EGR with this pipe still in place? eg will the EGR valve remain closed with solenoid unplugged and vac line removed? then i could just cut and blank on manifold egr lines?
It shouldn't be welded, is it that rusty or literally has been welded in the past? I wouldn't be bypassing anything unless I can plug that hole up first so the EGR valve doesn't receive any gasses from the exhaust manifold.
for the hard line that goes into the exhaust manifold, do you have the blanking plug (available through concept z and others) What i have done in the past is cut the hard line as close to the fitting as you can, which allows you to get a socket onto it. a big breaker bar and a heap of extension bars will allow you to have a good bit of leverage to get it out. use penetrating oils if needed. once its out, either fit your new blanking plug, with some maniseal or other heat resistant selant, or if you have got the old fitting out in reasonable shape you can weld the hole up and use that as the blank. this seems like a prick of a job, but so long as you can get a good socket on the fitting, it will come out. if you got unlucky and it rounds off or just wont come out, i geuss a exhaust shop could weld the hole shut for you, but that shouldnt be needed.
I disabled my EGR by removing the vacuum feeds and solenoids. No error codes, car runs fine, EGR valve stays shut. The system is still physically in the car, it just doesn't do anything anymore.
if the only intention is to disable and not remove, this is probly a good option. it is nice to have the extra space at the back of the engine though for doing bellhousing bolts etc
that was the answer i was after thanks. wasnt able to remove the big feeder pipe as it will seized and nut was beginning to round off. removed plug and vac lines to egr valve and trimmed manifold feed egr lines for access. just to be sure nothing comes out blanked them of with dyna bolts and a lot of high temp RTV.
I've removed and refit my gearbox since and to be honest I didn't find the EGR stuff got in the way of removing the bellhousing bolts. I'll eventually remove the EGR hardware, but probably only when I'm doing a plenum pull and/or header swap.
It is all good as long as you blocked exhaust gas intake to the manifold. If you just pull the vacuum of the EGR you leave the option for gases to leak out trough EGR valve in to your intake manifold.
That'll only happen if your EGR valve is stuck open, which will be fairly obvious as the car will run like garbage. I haven't blocked off the EGR fittings on the plenum, and my car is fine. Without a vacuum feed, the EGR valve will stay shut.
It depends on amount of boost presure that is required to push egr's valve spring open and let some exhaust gases in to the manifold. I wouldn't exactly know the spring rating on the egr, but you don't want it to open on high boost... And then it tends to open. Thus why kit is made. But if you running stock boost you don't have much to worry about.
The kit with the plug for the exhaust manifold is only there so that you can plug the hole when the valve is removed. The valve itself is vacuum operated; it isn't pushed open via exhaust gasses (it can however leak or be stick in a partially opened state). It will never see boost.
Well not really.. I just happened to have my old EGR on the shelf and I went to check the spring loading on it and wow it is so week that you wouldn't believe. However if you have a look at the image below, it shows the back of the engine and pipe that are enters EGR from very bottom, straight of the manifold (this side is also pressurized or phenomenon called "back pressure" it usually accrues when turbo is making some positive pressure in to the inlet manifold or "boost pressure". The pressure ratio varies with choice of turbos that is in the setup but I'll state 2:1 here.) Two pipes on the side of the EGR go to the plenum. So yeah you can just unplug the vacuum but it won't hold much of your boost until it starts leaking!
I've pulled enough of these off to know where they hook up. Considering wastegate spring pressure etc I'd be surprised if there's enough pressure in the exhaust manifold to push the EGR open but that's just a guess I haven't measured. Yes have also read the Garret tech articles and familiar with boost pressure and turbo operation re backpressure etc...
I know that you know all this below, but I have to mention it for the guys that don't. Wastegate is controlling over-boost and opens to release "back pressure" in order slow down turbo spin. EGR is controlling amount of exhaust gas intake in to the manifold at "Idle" (when you have vacuum in the inlet) to operate the diaphragm and pull the EGR valve up. In order to minimize on emissions and smooth the engine run at IDLE. Totally useless if you asking me... In general those two systems don't really work together... So what is happening with EGR at high back pressure? (I'd say somewhere over 7psi boost pressure) Spring that pushing EGR valve down simply gets overpowered by back pressure and let go. Then you get exhaust gas inserted in to the inlet... And this is the time when you should have maximum possible amount of oxygen in your intake!
Dude how on earth would that happen. If there's enough pressure in the intake manifold to push the EGR valve open, then all its going to do is dump air into the exhaust. Not the other way around. You'll have a boost leak and a rich AFR but your engine won't blow up. But that's not going to happen, because on anything but a highly-modified turbo engine (we're talking Le Mans cars here) there's always more exhaust manifold pressure than there is intake boost pressure. Look at where the exhaust gas feed for the EGR valve is, and you'll see that exhaust pressure will keep that EGR valve shut. Simmo, you've got nothing to worry about. You don't have to bother with blanking off those EGR pipes - as Rob260 pointed out, the blanking plates only exist for those who've gone the extra mile with removing the EGR.
It can only happen on earth, perhaps on some other planet that has same/similar gases mixture in the form of our air. And inhibitor with turbo'd ICE I will have to correct you a little bit on your quote in RED text above. Any turbo engine will always have more exhaust manifold pressure than intake boost pressure! This is huge subject and I simply don't have time to explain it, as it will end up in 5 pages of txt that no one will ever read... But yeah ERG will start to creep out in to the intake, while boost pressure is lower than back pressure and burnt gas will flow in to the intake manifold. Engine won't blow up, but it will decrease the amount of O2 in the air mixture when burnt gas is substituted. So it defeats the purpose and it should be removed in full
