Topic: Blocking off EGR Valve... (Read 4170 times)

24_Valve · « **on:** 28 August 2010, 17:42:04 »

I'm going to be sealing off my egr valve, some time soon... tin can etc.. question is whether this will increase CO, HC etc. Already trying to get my CO down for 2nd MOT retest and don't want to make it worse. Should I wait til after MOT?

24_Valve · « **Reply #1 on:** 28 August 2010, 23:53:06 »

anyone know

geoffr70 · « **Reply #2 on:** 28 August 2010, 23:56:56 »

I know nothing about this other than what i read in Haynes. It says egr is to reduce emissions, so if you block it off I'd have thought your emissions would go up.

24_Valve · « **Reply #3 on:** 29 August 2010, 00:10:17 »

thanks geoffr70 that what I'm guessing too

Was hoping that other OOF members who have already blanked their EGR might know what difference if any, that it's made to their CO reading? and curious as to whether they leave it blanked off for MOT or not?

aaronjb · « **Reply #4 on:** 29 August 2010, 00:22:03 »

EGR is there to reduce HC and NOx emissions during cruise states - it should be (assuming it's not broken in some way) closed during idle and high load (rapid acceleration) states.

I don't believe it would affect your MOT test emissions results; at idle the valve is closed so the natural idle test would certainly be unchanged, and I believe the fast idle test is most likely beneath the EGR opening threshold also and would also remain unchanged.

If, of course, the valve is sticking open or leaking exhaust gasses into the inlet manifold when it shouldn't be, then it most certainly could positively affect your emissions.

24_Valve · « **Reply #5 on:** 29 August 2010, 00:49:21 »

Quote

Posted by aaronjb Today at 00:22

If, of course, the valve is sticking open or leaking exhaust gasses into the inlet manifold when it shouldn't be, then it most certainly could positively affect your emissions.

Hmmm that could be a clue, I wouldn't be at all surprised if it were sticking open because it's about the only thing I've never cleaned or serviced :-/ do you mean "positively" in the mathematical sense i.e. raised CO ??

Kneepad · « **Reply #6 on:** 29 August 2010, 01:02:12 »

I suggest you wait until after the MOT. You'll just kick yourself silly if it fails on emmision.

aaronjb · « **Reply #7 on:** 29 August 2010, 13:16:40 »

Quote

Hmmm that could be a clue, I wouldn't be at all surprised if it were sticking open because it's about the only thing I've never cleaned or serviced :-/ do you mean "positively" in the mathematical sense i.e. raised CO ??

No I meant positively as in 'in a good way' .. so.. negatively in a mathematical sense

(less CO

)

ballcock50 · « **Reply #8 on:** 29 August 2010, 18:13:34 »

Hasn't effected my emissions at mot cost me 2p to do literally 2 x 1p pieces unbolted popped coins over holes and rebolted. Job done.

geoffr70 · « **Reply #9 on:** 31 August 2010, 00:33:46 »

Sorry to hijack another post and for being ignorant. What benefit is there in blocking off the EGR? Thanks

mark.adams · « **Reply #10 on:** 31 August 2010, 06:54:55 »

The benefit for a smaller engine is negated, apart from not feeding exhaust gases back in your inlet, for a bigger engine however, you could have a performance issue if you are burning previously burnt gases, easily blocked off with the metal from a cut open coke can, cut to the shape of the gasket.

DaveL · « **Reply #11 on:** 31 August 2010, 07:46:42 »

Quote

I'm going to be sealing off my egr valve, some time soon... tin can etc.. question is whether this will increase CO, HC etc. Already trying to get my CO down for 2nd MOT retest and don't want to make it worse. Should I wait til after MOT?

Have you tried one of the addatives into your petrol, to clean the gunk out of engine combustion? I have had good results with Cataclean and also a Forte product. My ECR was playing up and even cleaning did not cure it. Ended up buying a new ECR from Dealers. Still problems with emissions with mine till I went down the 'chemical' route. Also an Italian tune up did no harm.

HTH.
DaveL

2woody · « **Reply #12 on:** 31 August 2010, 10:30:03 »

you'll not notice if EGR is working or not. It doesn't feed back enough gas to affect the power or emissions.

the phrase "it's there for emissions reasons" refers to the type-approval emissions test, which is for manufacturers to do before the car goes on sale. This is a very tough test and takes four days to do, using machinery costing £10M +

in detail, the feeding back of a small amount of burned exhaust gas reduces the NoX content of the exhaust under certain conditions. NoX isn't even measured for MOT - the equipment is just too expensive.

actually, smaller engines need EGR the most. NoX is generated at higher combustion temperatures, when the engine is working hardest. The EU drive-cycle for the emissions test requires about 50BHP to run, and so a smaller engine wioll be working harder and therefore producting more NoX

aaronjb · « **Reply #13 on:** 31 August 2010, 11:09:30 »

Quote

you'll not notice if EGR is working or not. It doesn't feed back enough gas to affect the power or emissions.

You definitely notice it on the turbo diesel.. but I agree with you in general on a petrol car (it's just that on a turbo car you end up blowing boost down the exhaust pipe if it's stuck open, and you really tend to notice that from the massive lack of power and billowing black smoke .. ask me how I know

)

2woody · « **Reply #14 on:** 31 August 2010, 11:12:07 »

obviously, if it's stuck open on a turbo car, you'll notice :-?

cem_devecioglu · « **Reply #15 on:** 31 August 2010, 12:46:41 »

for the 2.5 v6, power slightly drops when the egr is open.. and consumption on the average will drop 0.5 litre/100 km if you block it (from the road computer- if its correct) ...

johny5 · « **Reply #16 on:** 31 August 2010, 14:52:02 »

Tried and tested on a 2.5 V6 vectra with no problems in running or mot.

24_Valve · « **Reply #17 on:** 31 August 2010, 19:21:14 »

Based on all the feedback I'm going ahead with blanking the EGR, just can't see how re-burning exhaust gases can in any way benefit my CO reading... Just replaced the Air Filter & this seems pointless if filthy fumes are gioing to be mixed with nice clean air... I understand the reason it's there.. EU regs relating to NoX but not too worried about that

Update: new plugs, new air-filter, 475ml of Cataclean, reset ECU and one-shot of redex just for good measure.. all I need to do now is blast it down to the MOT station and hope for the best... if not, then back to the drawing board

star_whites · « **Reply #18 on:** 31 August 2010, 19:23:14 »

Will blocking this off stop the additional clicking noise that you get when it is blowing I.e. I have black carbon marks where it is bolted in place and can hear s clicking noise coming from it!

24_Valve · « **Reply #19 on:** 31 August 2010, 19:35:41 »

sorry i haven't got a clue :-/ but reckon that one of the other members can help

Kneepad · « **Reply #20 on:** 31 August 2010, 19:54:09 »

Quote

Will blocking this off stop the additional clicking noise that you get when it is blowing I.e. I have black carbon marks where it is bolted in place and can hear s clicking noise coming from it!

don't know if it will stop the clicking but the fact that it has black carbon marks in indicates that it's leaking. I would get it off and clean it. You'll be surprised how much crud there is in there.

aaronjb · « **Reply #21 on:** 31 August 2010, 20:54:29 »

Quote

sorry i haven't got a clue :-/ but reckon that one of the other members can help

That reminds me - you're not a million miles away from me, let me know if you want a hand with it.

Alldi · « **Reply #22 on:** 31 August 2010, 23:03:56 »

I blocked mine off and it has always gone through the MOT emmissions test no problem, it can't be that important as Vauxhall scrapped it for the 2.6 and 3.2 engines and in an article in Professional Motor Mechanic Oct 2002, they recommend it's blanked off. I just cut a gasket out of an old metal biscuit tin lid.

24_Valve · « **Reply #23 on:** 31 August 2010, 23:53:13 »

turns out there is a GM part number for the blanking plate to fit Astra MK4, Signum, Vectra C, Zafira (Z22SE engines) GM Part Number: 24575592 So does that mean you can "Officially" blank your egr for an MOT, I mean actually lose the egr all-together and blank it off! or is there some bone-head section in the MOT hand book to prevent such activities

johny5 · « **Reply #24 on:** 01 September 2010, 00:26:39 »

There are blanking kits around or you can make one up urself. The egr isnt a part of the test, just emissions.

one point worth mentioning though is if u do do it, keep the plug connected otherwise u will get the engine management light on.

24_Valve · « **Reply #25 on:** 01 September 2010, 00:30:18 »

thanks johny5

Kneepad · « **Reply #26 on:** 01 September 2010, 01:00:04 »

A hypothetical question. If one blanks off the EGR valve, then a modification has been made to the car.
Should the insurance company be notified

It could be a get out for them if you have a claim. :-/

24_Valve · « **Reply #27 on:** 01 September 2010, 01:45:58 »

Kneepad is that pic of you?? you look quite intimidating

I'll have watch what I say to you

anyway re: the insurance question I think it could be a grey area if you're using a GM part made for that vehicle? whereas coke can etc. would definately be used by insurers to try and wriggle out of paying up

Kneepad · « **Reply #28 on:** 01 September 2010, 01:58:22 »

Yup I'm afraid that's me. Nothing to be intimidated by. I'm just not photogenic.

I worry about insurance companies. They like to take the premiums but that's it.

I am in two minds about the mod. Today I took my egr valve off with the intentions of blanking it but I finished up giving it a good clean and putting it back on the way it was.

24_Valve · « **Reply #29 on:** 01 September 2010, 02:23:52 »

Spot on, they just want the premiums

will pm you with details for a laser cut blanking plate that can be used with EGR in situ... even the most experienced assessor wouldn't pick up on it... trust me I know one

Kneepad · « **Reply #30 on:** 01 September 2010, 09:20:16 »

Appreciate that.

24_Valve · « **Reply #31 on:** 02 September 2010, 00:24:47 »

your welcome, btw sent new pm

Broomies Mate · « **Reply #32 on:** 02 September 2010, 00:33:34 »

Why oh why would an insurance company be worried about blanking off an EGR valve?

Christ alive!

star_whites · « **Reply #33 on:** 02 September 2010, 12:31:17 »

Well I removed my EGR last night and fitted a blanking plate made out of a coke tim. Took all of 20 minutes and that was because I couldnt find the right size drill bit lol

Hopefully no more leak

Jimbob · « **Reply #34 on:** 02 September 2010, 12:36:35 »

coke tin etc will just prove it works....give it a month and it will have melted through.

Needs to be MUCH more substantial.

Kneepad · « **Reply #35 on:** 02 September 2010, 14:53:07 »

Quote

Why oh why would an insurance company be worried about blanking off an EGR valve?

Christ alive!

A hypothetical question. Was meant to be taken as such.

Many people do modifications without giving the insurance companies a thought.

aaronjb · « **Reply #36 on:** 02 September 2010, 16:17:20 »

Quote

A hypothetical question. Was meant to be taken as such.

Many people do modifications without giving the insurance companies a thought.

A valid point - I mean, in the 'real world' it's highly unlikely to be a problem.. but you're right, insurance companies do like to do everything possible to wriggle out of insurance claims!

johny5 · « **Reply #37 on:** 02 September 2010, 18:08:23 »

5p piece and exhaust sealant does the trick

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Author Topic: Blocking off EGR Valve... (Read 4170 times)

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