how to bypass a mk7 egr valve?

[Rick the Spud]

A faulty EGR doesn't always put the EML on.

pull the EGR plug off...

[Mike]

A faulty EGR doesn't always put the EML on.

pull the EGR plug off...

Well done Rick, you win todays 'I've completely missed the point' award.

[winterheating]

there must be a way of blocking this thing off
with the mk6 i am lucky as it is just disconected and doesnt put the manegment light on

if you every have your pcm read for faults you will prob have an error with the MAf as the tdci as you know has no position sensor but the pcm can monitor the EG circuit by the Maf and some points uses the Map sensor.

[winterheating]

on the mk3 mondeos, the EGR at the front of the engine has a position sensor on, so needs to be connected still, but blanking the exhaust gas from entering eventually brings the light on, on the mondeo forum they all drill a 6mm hole in the blanking plate to keep the Pcm happy, but i think that defeats the object of blanking as it only take a bit of exhaust gases to recirculate to clog everything up, plus if the pcms happy then theres enough exhaust gases entering to do the job the egr is supposed to do.. total waste of time.

so the Pcm on mk7 transits must do the same, i take it the only difference with the mk7 EGR valve is the geared motor operates the EGR valve instead of previous type vacummn operated ones, the position sensor is the same, and because
the PCM knows when you blank the exhaust gas it must monitor flow by the Map sensor and Maf(do all mk7's have a Maf )
so i think easiest way to fool the system would by to re route intake and blank exhaust gases, and allow the EGR to pull in fresh air instead of exhaust gases

the exhaust manifold can be blanked were it normally feeds the EGR valve.
the pcm shouldnt know the amount of exhaust gas thats leaving the engine.
but it will know how much gas is recirculating as it will be deducted from the flow through the air meter, so having the normal exhaust connection of the EGR valve connected to routing pipework inbetween the normal air filter and the MAF , as its before the MAF it wouldnt see it.
so as EGR valve opens it would prob let boosted air back through EGR which would then go back before Maf again, which would also give extra boost to the air being drawn in by turbo compressor, so no boost should be lost at all, and Maf should be fooled.

the only thing then that may still upset the PCM is the Map sensor readings, i would of thought when EGR allows exhaust gas to recirculate then boost would be increased slightly

i might try this on my 130ps tdci mondeo when i get time, i have the EGR disconnected on that with the light on.

[Luke]

i think easiest way to fool the system would by to re route intake and blank exhaust gases, and allow the EGR to pull in fresh air instead of exhaust gases

thats an idea

[winterheating]

i think easiest way to fool the system would by to re route intake and blank exhaust gases, and allow the EGR to pull in fresh air instead of exhaust gases

thats an idea

i'll try it out on my mondeo one night..... unless someone wants to drop their mk7 off with me for a week....

[ake]

Where would you reroute the egr inlet to The air cleaner

[ThommoHawk]

Hmmm - very interested in this thread as i've recently seen an EGR Horror Story on my old Merc Vito -(spit spit, cough! - sorry for swearing!)

Anyway I pick up a 56 plate 300/130 next week so will definitely be taking a look at this issue sooner rather than later.

My background / daily work revolves around electronics so if I can come up with a solution, I'll be sure to post details here.

[winterheating]

Where would you reroute the egr inlet to The air cleaner

yeah basically as long as its before the Maf sensor.
then its just how much boost is lost causing turbo to work slightly harder, or the boost re entering the intake before turbo may just balance it out.

[winterheating]

actually thinking about it again, connecting the boosted air going back through the EGR valve to before the Maf will just look like air used so it would have to circulate after the Maf sensor but still into un boosted air supply, then that way its recirculating the same as exhaust gas into intake, but it would be fresh air into fresh air basically just bypassing engine.

[GBBiker]

Does anyone know what resistance range is thrown out by the EGR?

I'm thinking it may be possible to knock up a little black box of electronic goodies to fit onto the EGR multi-plug and fool the EM system by providing a variable reststance output. Then you can just take out gears and cogs to your heart's content

Shouldn't cost a lot to make.

Can anyone tell me how the resistance reading changes with engine condition (ie; temperature, revs, etc.)?


If I have that info, I can look into the possibility of building some little modules to do the job.

[STEVE P]

Put me down for one if you get them made.

Will all the engines need the same box of tricks?

Steve P

[winterheating]

Does anyone know what resistance range is thrown out by the EGR?

I'm thinking it may be possible to knock up a little black box of electronic goodies to fit onto the EGR multi-plug and fool the EM system by providing a variable reststance output. Then you can just take out gears and cogs to your heart's content

Shouldn't cost a lot to make.

Can anyone tell me how the resistance reading changes with engine condition (ie; temperature, revs, etc.)?


If I have that info, I can look into the possibility of building some little modules to do the job.

the pcm uses position sensor on EGR, you could keep that operating and blank exhausat gases off, but it still knows cos of the airflow readings, so fooling the position sensor would be totally pointless.

plus taking the cog out of the gears is surely exactly the same as fitting a blanking plate

[Rick the Spud]

A faulty EGR doesn't always put the EML on.

pull the EGR plug off...

Well done Rick, you win todays 'I've completely missed the point' award.

haha, yeah sorry.

just in a different frame of mind that day, i knew my egr was on the blink and ford wouldn't touch it until the light came on, so i unplugged it, and it did!

[winterheating]

success

i did a little bit of fiddling with egr piping and after a few miles light is gone
it worked just how i thought it would

this is on a mk3 mondeo, all we need now is someone to try it out on their mk7

pictures to follow.