Club 80-90 Forums

hi whats peoples views on the aaz engine egr system . do you leave the system on or fit plates to cut egr out

I am going to leave it on my 1Y - people seem to have removed them from 1Ys as they don't use the 1y manifolds.

The advantage of EGR is that when working properly, it reduces NOx in the exhaust gases by cooling the burning process down a bit. The disadvantage is that it uses exhaust gases to dilute the charge, and those gases contain soot. The soot mixes with oil carry-over from the turbo to make tar, which coats the inlet throats and restricts the incoming air charge. This produces even more smoke, which makes even more tar. After 50000 miles or so you can expect the inlet manifold to be 25% restricted, and the vehicle smoking heavily, so you have to remove it to clean it out. It's a filthy job. You also need some kind of controller for the system.

My personal preference has always been to blank EGR off, reducing visible smoke and increasing power output at the expense of NOx emissions. Blanking off will increase exhaust gas temperatures too, so that would be something to watch on a turbo engine. It depends on where your priorities lie.

Here's what EGR does for your inlet ports................

Not pretty, is it?

hi thanks for the reply i have bought blanking plates for th egr but unsure where i block it of any ideas or pictures to show would be much appreciated

You should have some bits that look something like this..............



If you have two blanking plates, throw all the bits in the photo away and fit one blanking plate to the inlet manifold, and one to the exhaust manifold, where those bits would have gone.

If you just have one blanking plate, fit it as per the note in the photo, and leave the valve in place.

Make sure you clean all the black gunk out of the inlet manifold, and also fron the inlet ports on the head too. Clean the inlet ports by making sure the inlet valves are shut and scraping it all out with a piece of bent wire/paraffin/rags/anything you can get in there. This will improve performance no end. A horrible job, but worth it.

thanks of the egr i have a pipe which goes to the bottom of the turbo looks like a breather pipe or something do i just block this off

Just bin all the egr parts...vac pipe, valve, solenoid, the lot....it's rubbish and belongs in the scrap bin, then set to cleaning out the inlet manifold and de gunge the head......some AAZs don't have it anyway and if using a JX exhaust manifold you can't use it either....it's bad news, a factory hodge to get round an emission issue, but causes long term more emissions due to choking the engine.



Not a egr fan...can you tell?

Oh, and leave the small pipe to the turbo actuator open to atmosphere or it will affect the waste gate operation....

hi sorry to jump on some ones thread but im inthe process of fitting an aaz , what do i do about the large vac pipe from the block ?(its from a td golf )
block it off or leave it open ?

thanks in advance

I blocked it off on mine with the plate from the JX block. I have wondered, since, if it was the right thing to do - as obviously there is a breather there for a reason. I'm assuming it's there to relieve crankcase pressure/recirculate air ... but not sure.