EGR Blanking - For & Against

Tesla

Tesla

Tesla

Soldato
Joined
19 Jan 2003
Posts
17,601
Location
Bristol, UK
If I understand correctly an EGR valve directs exhaust gasses back into the engine air intake in order to reduce internal engine temperatures?

Are there other benefits to this? Does this process effect emissions? Is it advisable to blank off the EGR?

The main reasoning behind this question is I need to take the UIM off of my Mondeo to allow easy access to fit new spark plugs and also replace a vacuum line which may be damaged.

As the UIM is coming off I may aswell take the LIM off too. Judging by threads on the Mondeo forum they are both likely to be full of carbon deposits and cleaning them out yields some reward. Is it the EGR that causes all this carbon build up?

I also want to test for a leaking injector and may get the injectors cleaned if everything is off anyway.

All quite cheap jobs so would seem sensible to do it all in one hit.
 
It's mainly for cold start and emissions reasons, if it's anything like mine you will have an air pump which forces air into the EGR system to help reduce startup emissions.

I've removed all my EGR system and fitted a blanking plate, it's had no effect on engine temps.
 
Why did you remove yours Mark? What are the benefits?

Would the emissions be out enough to fail an MOT without the EGR system?
 
EGR redirects exhaust gas to replace some of the mixture in the cylinder, this lowers the combustion temperature, and reduces the formation of N0x (which forms much quicker at very high temperatures)

Its all emissions related garbage, which usually leads to heavy intake and valve deposits. People remove it to prevent this build up (In some engines it can, for example, leave enough deposit to halve the size of some airways). It is also supposed to unlock a little more power, as you re-gain the lost space in the cylinder usually occupied by EGR gas, so you can fit in more explosive fuel/air mix.
 
for. egr causes big issues for one of my pd130s years ago.

i blanked mine back in 03-04, years before you could get kits, making a gasket (without a hole) using a beer can! car was vastly improved after. beforehand it was so screwed that it was leaving soot tracks
 
Tesla said:
Why did you remove yours Mark? What are the benefits?

Would the emissions be out enough to fail an MOT without the EGR system?
Click to expand...

I mainly removed mine because the secondary air pump was playing up and was making the engine sound like a tractor on startup, instead of replacing it i just ditched the whole system, in addition i wanted to avoid buildup of junk in the intake system.

MOT wise it should be ok, the EGR system is only active during startup and idle (irrc) since the valve is of manifold vacum based operation, under engine load (MOT test conditions) emissions should be exactly the same as before.
 
Thanks guys. I think I will blank it off but not remove the system.

I don't fancy spending hours cleaning the inlet manifolds to them then being full of soot again!
 
Nomisf said:
EGR redirects exhaust gas to replace some of the mixture in the cylinder, this lowers the combustion temperature, and reduces the formation of N0x (which forms much quicker at very high temperatures)

Its all emissions related garbage, which usually leads to heavy intake and valve deposits. People remove it to prevent this build up (In some engines it can, for example, leave enough deposit to halve the size of some airways). It is also supposed to unlock a little more power, as you re-gain the lost space in the cylinder usually occupied by EGR gas, so you can fit in more explosive fuel/air mix.
Click to expand...

That makes more sense.
 
Can you blank it off with a plate but still leave everything connected up?

Or will this confuse the ECU?
 
As said, depends on the car - my M47R engine doesn't miss it at all, yet some of the Peugeot engines I have worked on throw an EML when the solenoid is removed.
 
Yeps it's not exactly the same as the TDI EGR but it does a very similar job, its called a combi valve on mine but the principal is largely the same (emissions reduction).
 
Last edited:
From some brief reading I did the other day on the Mondeo I can block it off and not throw an error code. If I disconnect or do something to the vacuum then it does throw a code.

I will double check but I note a fair few people on the Mondeo forum have done it so there is likely a solution.
 
Firestar_3x said:
Yeps it's not exactly the same as the TDI EGR but it does a very similar job, its called a combi valve on mine but the principal is largely the same (emissions reduction).
Click to expand...

oooh thats what that does. i knew it functioned via the n112 valve for the secondary air intake. didnt know it did egr too

best have a look into that
 
Basically, I have unplugged mine and it's been fine, no error messages at all on my Fiesta ST so blanking it up won't be an issue. Was just wondering if there was a hidden bug if it was blanked off but still plugged in, like would the ECU see it, adjust a parameter of the engine and because of that, cause damage because the EGR was actually blanked off.

Either way, I can just leave it unplugged and have no issues, was just interested more than anything.
 
You must log in or register to reply here.
Back
Top Bottom