how does EGR system work?

Wookey · Unread post by **Wookey** » 27 Jan 2005, 02:28

OK - I've found a likely donor vehicle for turbo-connecting parts but it's an 806/synergie/ulysse, rather than the expert/dispatch/scudo I actually have. THings are nearly the same, but:
The exhaust manifold on these doesn't just go to the turbo - it has an extra spigot for what I believe is the EGR system:
expert/dispatch/scudo plain manifold:
http://www.elcats.ru/impeugeot/U64FQU17A55A.gif
806/synergie/ulysse manifold
http://www.elcats.ru/impeugeot/U60FQF17A55A.gif
This seems to show the system that connects to it:

What on earth is all this stuff? And what are the other bits it connects to (e.g. what does pipe 13 connect to, and what are the two greyed-out things the small pipes connect to? I don't recognise any of these, and suspect I don't have them.
What are the pros and cons of EGR?
So, my options are:
1) Use this manifold and make a seal to bung up the extra spigot. Not sure how easy this would be. Just welding it shut should do the trick?
2) Get all this EGR stuff. Might be good for my emissions? What other parts does it imply (e.g. do I need a cat?, different pipes?)
3) Go and find/buy the correct plain manifold (neatest, but I still have to find one or cough up to peugeot). 6 scrappies couldn't help today, and no responses from two internet parts searches.
Which would you do?
One more question - Does having a cat exhaust imply the need for the EGR system to protect the cat?

AndersDK · Unread post by **AndersDK** » 27 Jan 2005, 03:40

I recognise these bits from my BX19 diesel.
This EGR system (cant remember what the abbrev is for) was a legal demand on Swiss & Swedish BX diesels in the late '80's, and some of these BX diesels ended on the DK export market.
Basically the EGR system takes some of the exhaust and recirculate it into the inlet - to bring down the pollution.
Hose 13 interconnects inlet & exhaust manifolds via valve 10, which in turn is vacuum operated by the rest of the stuff - including a special ECU 16.
Defo no fun to retrofit. I'd certainly blank off the valve 10 hole on the manifold.
I'm not sure this EGR system is needed in the UK - at least on this yearmodel ?

beezer · Unread post by **beezer** » 27 Jan 2005, 05:46

EGR = Exhaust Gas Recirculation.

rossd · Unread post by **rossd** » 27 Jan 2005, 12:38

Just blank the hole on the inlet manifold with some steel plate and a couple of bolts, you will need a gasket to make it seal. Running without the EGR on the XUD will give you improved economy and slightly better performance (if you notice it). Its not actually a requirement as such in the UK.

bxbodger · Unread post by **bxbodger** » 27 Jan 2005, 12:40

<blockquote id="quote"><font size="1" face="Verdana, Arial, Helvetica" id="quote">quote:<hr height="1" noshade id="quote">This EGR system (cant remember what the abbrev is for) <hr height="1" noshade id="quote"></blockquote id="quote"></font id="quote"> - Exhaust Gas Recirculation system.
If you don't already have it fitted, you won't need it as the UK MOT emissions test is done by the age of the vehicle rather than the age of the engine thats fitted to it.

oilyspanner · Unread post by **oilyspanner** » 27 Jan 2005, 16:07

Blanking off the EGR system is a well known performance/economy mod on Transit vans too, you can definitely live without it.
Stewart

Kowalski · Unread post by **Kowalski** » 27 Jan 2005, 17:54

EGR isn't a requirement for the MOT on diesels, they only have to pass a smoke opacity test.

rg · Unread post by rg » 28 Jan 2005, 01:47

Isuzu issued a mod for the Trooper to isolate the EGR, as sticking EGR valves were more troublesome than they were beneficial. Symptoms were loss of turbo and smoke out the back. Horribile and scary.
rg

samcro · Unread post by **samcro** » 28 Jan 2005, 14:17

Have disabled the EGR on my 106 1.5D with no detrimental effect. (slight increase in performance but only minimal). You could safely blank it off and forget about it. The EGR valve will likely be operated by the brake servo vacuum.