Aussie GSi
Member
Registered: 5th Aug 02
Location: Sydney, Australia. Drives: Corsa B GSi 16v
User status: Offline
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Hey guys 
I've read that 'Molasis' is having a bit of trouble with his EGR valve too.
I'm currently on my 3rd EGR valve, and my car is still playing up. I've been told by Holden (GM Australia) that it may be something that I have to just live with. Meeeeeeep! Wrong pecker dik!
Every now and then, this happens:
*Driving along, normally. Not doing excessive speed or revving her high. Just calmly driving - highway or through residential streets - anytime. My ECU warning light comes on, and my revs go really eratic, decreasing rapidly, until the car stalls.
*Sometimes I can start the car again, and everything is fine
*Other times, she wont want to start. Or if she does start again, the problem is still there, revs drop, and engine stalls again. Have to keep trying to start her until she does run fine. Can be hard to start.
I've taken her to GM 3 times so far. 1 of those times, I couldn't drive her, and had to have her towed in (due to this problem). They plugged her in to the diagnostics machine (with the engine faulting), and she read *CODE 47* - EGR Valve and some other code for Crank angle sensor. Had both replaced.
The other 2 times (after the first above) I've taken her to GM, they plug her in, and apparently she reads nothing. Nothing in the ECU memory, no fault codes.
But the bloody problem is still happening!
Now, alot of people are talking about blocking off the ports to the EGR valve. It would be greatly appreciated if you guys can help us with this.
*What will be the difference in emissions?
*Why does this work?
*If I'm on my 3rd EGR valve, couldn't it be something else? I.e. Could the problem actually be in the ECU, not the EGR valve?
*Is there anything else that influences the EGR valve? (i.e. could be interfering with it, or could be stuffed, affecting the EGR)
*Is there anything else that could be going wrong with my engine?
*Does anyone know of any good Opel specialists that I could email to ask about this?
I know that you can not just rip out the EGR, as it has an output wire connected directly to the ECU.
Fellas and ladies, any help would be so greatly appreciated. As you can guess, I'm starting to get a tad annoyed with this bloody EGR thingy! (Just a tad)  Holden have got no bloody idea about my car. But, hey, why would they? They only SELL and SERVICE Opel cars, but why would they know anything about them?
Also, could someone please post another pic of the EGR or where it is in the engine bay. I couldn't view the pic in Molasis's thread.
Thanks again guys. Greatly appreciated.
C
[Edited on 20-05-2003 by Aussie GSi]
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GAZ914
Member
Registered: 28th Oct 02
Location: Sydney, Australia Drives:Corsa C SRi 1.8
User status: Offline
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There is a lot of speculation about EGR valves, why they are there and what will happen if they are removed.
The truth is that to get good efficiency (read fuel economy, power and low hydrocarbons and carbon monoxide), the engine should be using high compression and lean(ish) mixtures, making the combustion process happen at high temperature.
The downside is that once you do that, the oxides of nitrogen (NO) readings go off the scale 
To aleviate this problem, engineers found that by introducing some exhaust gas into the combustion chamber (via the inlet manifold) the combustion temperature was reduced and, hey presto, we meet emission targets
Now, how does this info help us?
First off by blocking the EGR valve, the NO emissions will be higher. As the exhaust gas does not really interfere with the combustion process, then there shouldn't be any real issues, or power increase/decrease.
Why does the EGR valve cause the engine to run bad?
Normally because it sticks OPEN. This lets exhaust in at idle, when we don't need or want it. The mixture goes lean and the engine runs crap
In the case of the GSi, it sounds like the ECU monitors the operation of the EGR vavle (ie if it opens and how much). So blocking the ports off will probably fix the engine running issue (assuming it id the EGR valve causing the problem).
What won't stop is the ECU light coming on. If the EGR valve is stuck, the ECU will not see it "move" and so the light will continue to come on
It MAY be possible to clean/modify it to make the ECU happy.
More than that I can't really say, as I haven't seen one of the GSi valves.
GAZ
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Wolf In Welsh Clothing
Member
Registered: 31st Mar 03
Location: North Wales...... Cooper S on order
User status: Offline
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Block ur EGR off as its cheaper than a 4th one!
Replace your coolant temp sensor if you aint already done it.
Had similar probs on mine when the egr wasn't connected!
On migweb loads of peeps have said that they alwys replace the coolant sensor as the ecu doesn't log it when its faulty.
Only £14 and 60secs with a 19mm spanner.
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