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Posted

This is the EGR valve from my motor (not mine exactly, but how mine looks):

 

largo_egrv.JPG

 

The backside of this photo is what connects to the intake, but I haven't had it off to see if there are 1 or 2 holes there. The side you can see, with the threaded hole is connected to a pipe of a similar width (solid metal pipe) which from memory runs back to the block or somewhere. Can anybody help me clarify what this hole (the one you can see) is for, and if capping it should be as simple as the video I posted above?

Posted

I think you need to follow the EGR system right around - it may just appear to be from the block, but may be attached to the manifold rather close to the engine, and out of sight. I'm just watching the video bud.

 

DT

 

 

*Edit:

the video is correct - the part of your EGR valve that isn't visible on that pic - the one with the two holes - create a solid gasket as shown in the vid and place between the EGR valve and intake pipe. :)

  • Thanks 1
Posted
I think you need to follow the EGR system right around - it may just appear to be from the block, but may be attached to the manifold rather close to the engine, and out of sight. I'm just watching the video bud.

 

DT

 

 

*Edit:

the video is correct - the part of your EGR valve that isn't visible on that pic - the one with the two holes - create a solid gasket as shown in the vid and place between the EGR valve and intake pipe. :)

 

Thanks for helping, but please stick with me while I try and get over my confusion. Can you help with:

 

1) the gold nubbin at the right of the pic has a rubbery small pipe attached to it - what is this?

2) The other side of my EGR (that you can't see in the pic), will that have 2 holes as in the video, or 1?

3) The large pipe hole you can see - what is this for?

 

I understand the theory behind the EGR valve, but applying it to my particular model is difficult as it seems different to other more common valves. Can you explain how it works in relation to my model shown above, as an example (but obviously this is not correct, just trying to show how I need to understand it):

 

1) The little fairies come from your exhaust through the large metal pipe and into the EGR valve through the front hole in the picture

2) Pixies in the valve decide when to open and close the valve

3) When open, the fairies flow through into the other side of the valve (which we can't see) and back into the intake

4) The rubber pipe is just there for show

5) Capping it will just constantly keep a few fairies in the pipe, but they will not be able to get further, nor will they leak out, not will it build up pressure and make the coke can go pop

 

This is the sort of thing that helps me understand, so if you could do that I would be most grateful.

Posted

And one last question (for now) - is the EGR valve similar in principle to a PCV valve?

 

EDIT: And another question. How do I make a coke can the right size to fit if I don't take my EGR valve off?

Posted

That little pipe I am sure is a connected to create a vacuum that operates the egs valve itself no vacuum = no egr operation.

 

Disconnect the little pipe and stick a screw in it just to stop and debris ingress and pop something over where it used to connect to the egr valve itself?

 

Ben

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Posted

1) The little fairies come from your exhaust through the large metal pipe and into the EGR valve through the front hole in the picture

2) Pixies in the valve decide when to open and close the valve

3) When open, the fairies flow through into the other side of the valve (which we can't see) and back into the intake

4) The rubber pipe is just there for show

5) Capping it will just constantly keep a few fairies in the pipe, but they will not be able to get further, nor will they leak out, not will it build up pressure and make the coke can go pop

.

 

Fantastic!

It's correct though - the rubber pipe is likely a breather pipe - purpose unknown mine doesn't have one, but another 300tdi down the road does.

The EGR just recycles exhaust gases on the basis that a certain amount of said gas will be unspent vaporous fuel - thus recycling this will result in lower emissions (in theory).

The difference in emissions in negligible at best, blanking this off results in a better low-end torque as the intake system is sealed and continuous - thus providing the turbo with a good flow of cool air.

 

or so the theory goes.

 

DT

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Posted
A piece cereal box cut into the right shape will be satisfactory :)

 

Not for an EGR valve, Exhaust Gas Temp reaches 200+ degrees, so burning cardboard is no problem.

I used 2mm mild steel - the alu from a coke can is rather thin and I can't imagine it lasting very long.

 

DT

  • Thanks 1
Posted

So on mine, rather than having 2 holes on the backside like in the vid, I have a hole on the front and only one on the back? I've seen one step-by-step saying simply cap the vacuum valve off and this will effectively do the same job?

 

Like this: http://www.rx7.org/Robinette/egr.htm

 

EDIT: Says cars after '94 will flash EML so best to do it with the alum method.

Posted
So on mine, rather than having 2 holes on the backside like in the vid, I have a hole on the front and only one on the back? I've seen one step-by-step saying simply cap the vacuum valve off and this will effectively do the same job?

 

Like this: Disable EGR

 

 

EDIT: Says cars after '94 will flash EML so best to do it with the alum method.

 

the number of holes is purely down to the manufacturer.

As long as you're putting a solid gasket over it, it doesn't really matter.

Have you checked the dreaded auction site? there may well be some blanking plates for sale - you could find out what material is preferred for the plate.

Capping the vacuum valve may to some extent do the trick, but a sealed blanking plate just ensures that it is properly and physically closed.

There are a million and one ways to do it - it's just a matter of what you have time to do.

 

DT

  • Thanks 1
Posted

Ok, going to go with the blanking method I think, but my car isn't exactly popular like an Astra so nothing on eBay - home made job it is.

 

Just hope I can get the valve off as the big hole in the pic you can see, that nut was stuck solid.

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Posted
They're not too difficult to fabricate. But due to the horrendous coking of the valve parts usually get stuck (fused almost) on a monumental scale :(
Posted
Any special advice for undoing the nut? Tried belting it with a hammer some. Need to try and find something to fit the spanner to give more leverage.
Posted
Any special advice for undoing the nut? Tried belting it with a hammer some. Need to try and find something to fit the spanner to give more leverage.

Patience, and/or brute force I'm afraid. spray with WD40 and tap gently with a hammer - this may loosen the muck a little - it's then applying just the right amount of pressure so as not to round it off, and keeping it applied until it starts to shift.

Took me 2 hours alone on mine..... one whole tin of WD and a pound weight hammer, just tapping away, but it went eventually. try tightening slightly (1/16th turn) before loosening.

 

DT

  • Thanks 1
Posted
They're not too difficult to fabricate. But due to the horrendous coking of the valve parts usually get stuck (fused almost) on a monumental scale :(

 

Tell me about it. Luckily Astra ones are held on with 2 big Torx bolts, so I broke out the wrench, bit and a breaker bar..heh. Once it was off, I put 12v to it, and it was indeed utterly jammed.

 

Brought it into DT here, clamped it in a vice, WD40, big hammer, heat treatment blowtorch until nice and pretty, more hammering, more 12v pulsing, rinse and repeat. Soon started moving again!

 

Went for MOT last time, the guy looked under the bonnet.."I see what you did there..good call!". Never caused me any issues.

 

Thinking on, I bought a cheapo 12v impact wrench (think wheelbolts) - it took standard sockets too - one of those is a lifesaver for stubborn bolts. Satisfying too, hearing the flywheel spin up, then "CLUNK!" and off goes the bolt.

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