EGR to blank off or not?

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Mitsuru
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EGR to blank off or not?

#1 Post by Mitsuru » Sat May 05, 2012 8:33 pm

As I have been spending MY money to sort mothers car out I
haven't got any left to spend on mine!

So IF I blank off the EGR pipes and not use it, will this be
good or bad for the emissions for the MOT?

Or should I wait and get a custom made pipe set up made.
A set of blanking plates can be knocked up out of scrap metal.
I'm Diabetic,& disabled BUT!! NOT DEAD YET!!

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arceye
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Re: EGR to blank off or not?

#2 Post by arceye » Sat May 05, 2012 9:05 pm

Couldn't swear to it on your project but I've blanked them on diesels in the past as they can be troublesome at best.

My understanding was that their purpose was to lower NOx emmisions and also shrink the cylinder capacity slightly when cruising by adding the exhaust gas possibly making things a little more economical.

Nowt but trouble on things like Pajeros and the cause of black smoking and engine knocking when things gum up. On Pajeros a ball bearing in the vacuum pipe works just as well as a blanking plate though again I don't know how your set up works. I don't think NOx is even tested in the UK ( sure someone can clarify that) so you should be good to go, certainly never a problem on the diesels I've had.

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Mitsuru
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Re: EGR to blank off or not?

#3 Post by Mitsuru » Sun May 06, 2012 12:29 am

For pre 2002 cars fitted with cat (which Christine is)
The MOT emmisons test CAT test using default limits which are as follows
Minimum oil temp 60 C
Fast Idle: (2500 to 3000rpm)
CO <= 0.3%
HC <= 200ppm
Lambda 0.97 to 1.03
Idle: (450 to 1500rpm)
CO <= 0.5%

Those are what christine ill need to meet.
I'm Diabetic,& disabled BUT!! NOT DEAD YET!!

sierra3dr
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Re: EGR to blank off or not?

#4 Post by sierra3dr » Sun May 06, 2012 8:22 am

I thought the ecu wll detect it missing if blanked off?

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Luxobarge
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Re: EGR to blank off or not?

#5 Post by Luxobarge » Sun May 06, 2012 8:40 am

As Arceye suggests, the EGR is there to reduce NOx emissions. These are not tested, so it will pass MoT emissions test OK.

However, NOx is very toxic, and is produced due to the very high combustion temperatures in modern engines forcing the Nitrogen in the air to combine with oxygen to form NOx. Introducing a little exhaust gas into the induction cycle reduces these temperatures so that reaction doesn't happen - or is vastly reduced at any rate.

So the result of blanking off the plate will be much higher combustion chamber temperatures. This will a) stress the valves and seats much more, and b) cause pinking, which the ECU will deal with by retarding the ignition, so the engine will not be working at it's optimum designed parameters. You probably won't notice this until a valve burns out, a piston or spark plug melts or you get overheating problems. These problems are less prevalent in a diesel engine as the running temperatures are quite a bit lower to start with, the engine internals are tougher, and by definition they don't suffer from pinking, so removal is much more risky in a petrol engine like yours.

And yes, I may be mistaken but I believe you still need to leave the mechanism electrically connected otherwise the ECU will throw a code, which will put the EML on, which is an MoT fail (or will be soon - definately will be by the time you have your car on the road).

I'd leave it connected as the manufacturer intended if I were you, your call though.

HTH :D
Some people are like Slinkies - they serve no useful purpose, but they still bring a smile to your face when you push them downstairs.

jimmyybob
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Re: EGR to blank off or not?

#6 Post by jimmyybob » Sun May 06, 2012 8:36 pm

Some blacking plates have a small hole in them so the ecu is 'fooled' into thinking its still there.

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Mitsuru
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Re: EGR to blank off or not?

#7 Post by Mitsuru » Tue May 08, 2012 9:41 pm

I'd leave it connected as the manufacturer intended if I were you, your call though.
There isn't an egr pipe fitted as I would need to have one custom made.
As no money that means I will have to hold off on that till I have some
funds first.
I'm Diabetic,& disabled BUT!! NOT DEAD YET!!

wil
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Re: EGR to blank off or not?

#8 Post by wil » Sun Aug 30, 2015 8:51 pm

Three years ago my Pug 407 hdi 136bhp was going into limp mode on hills due to a faulty egr valve. I fitted a blanking plate bought on ebay fo about 3 quid and it has been fine since. :thumbs:

tractorman
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Re: EGR to blank off or not?

#9 Post by tractorman » Tue Sep 01, 2015 10:28 am

I'd go with Mr O'Barge's advice on this one - the car is designed to use EGR and, though some do modify them, there will come a time when they are tested - in much the same way as DPFs have to be fitted on diesels but NOX emissions from them are not --YET.

However, on the (diesel) Land Rover, someone had blanked the EGR-inlet hole rather than remove the EGR. I removed the EGR and plated over as there was nothing to control the EGR - the cables were connected, but they only went so far into the harness and nothing came out of it and the vacuum pipe was much the same - connected at the valve but free at the other end! However, the earlier Prima engine didn't have EGR (but had different injectors) and, obviously, is a diesel, so I don't expect too much trouble in future - especially as I won't exactly be racing down the motorways! TBH, if there had been some way of controlling the EGR on the Landy, I would prefer to have made the system work. That's because I like to reduce emissions etc where I can as it satisfies my interpretation of being green (no, I don't hug trees - I use a chainsaw instead as trees are a renewable energy resource!)

mr rusty
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Re: EGR to blank off or not?

#10 Post by mr rusty » Tue Sep 01, 2015 10:58 am

How does she drive it? I ask because I checked the egr on Mrs Rusty's diesel, it's done getting on for 200k now, but it turned out it was clean as a whistle. Most of her miles are motorway/fast A road however. I believe that when they do give trouble, it's nearly always on cars that are pootled around at low speed all the time, they coke up and stick open. They're only meant to open at very low engine speeds, and then close as revs rise and NOx falls. Obviously blanking them off sorts that issue but the odd thrashing would probably prevent it occurring in the first place.
1968 Triumph Vitesse Mk1 2 litre convertible, Junior Miss rusty has a 1989 998cc Mk2 Metro, Mrs Rusty has a modern common rail diesel thing.

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