Member Since: 12 Feb 2021
Location: Stroud
Posts: 196
EGR valves 5%
Hi all, was running some live values on GAP today. EGR command and EGR actual position for both sides.
I am not seeing any fault codes it was more out of interest, both EGRs were replaced by the previous owners garage a few months ago. The actuals seems to get down to 5% when accelerating but no lower for either side, they seem to be performing normally otherwise.
So with both commands at 0% on acceleration both egrs are reading 5%. Otherwise they seem to track the commanded positions pretty well.
Normal or something that needs looking at. ?
17th Jan 2022 11:42 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4873
They're fine Chris, when they have a problem they'll let you know.
And they will have a problem.....eventually yµ (idµ - eAµ) ψ=mψ
18th Jan 2022 12:22 am
Chris1573
Member Since: 12 Feb 2021
Location: Stroud
Posts: 196
Thanks Prof. I am thinking of blanking them anyway, am I right in thinking I just need to do the bottom two plates if I am leaving the pipes connected to the throttle body. Along with butterfly removal.
18th Jan 2022 12:37 am
aja4x4
Member Since: 14 Apr 2019
Location: Westbury
Posts: 2462
No you need to blank the throttle body as well and remove tne butterfly valveAndrew
D3 2.7tdv6 2005
D4 3.0 SDV6 Commercial died and gone to LR heaven
D5 3.0 SDV6 HSE
18th Jan 2022 7:19 am
Chris1573
Member Since: 12 Feb 2021
Location: Stroud
Posts: 196
Ok, AJA, So let me understand.
If you put the plates in between the pipe and the Valve the pipes are blocked off, so if the pipes are still fitted to the throttle body why would this be an issue? No air can be drawn through the EGR pipes if they are blocked off where they join the egr valve.
18th Jan 2022 7:37 am
Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10485
Chris1573 wrote:
Thanks Prof. I am thinking of blanking them anyway, am I right in thinking I just need to do the bottom two plates if I am leaving the pipes connected to the throttle body. Along with butterfly removal.
Correct
18th Jan 2022 7:43 am
Chris1573
Member Since: 12 Feb 2021
Location: Stroud
Posts: 196
Thanks Pete, So next question, if my egr valves are currently working and I blank them off, but leave them connected then as long as they continue to function even if blanked off then there should be no remap needed as they will not throw up any codes?
I guess this leads to the next question, what does blanking off healthy EGR valves do to them, whilst no exhaust gas will be flowing out of them into the throttle body i guess the exhaust gases and gubbins will still build up inside the valves as they are still connected at the exhaust side so over time they will potentially start to get gummed up and then you will get the codes that require a remap to turn off the EML…?
I am wondering whether blanking them actually leads to them failing more quickly as the build up of carbon will happen more quickly if there is no gas flowing through…
Yours is a MY2008 , going by your profile you will need a software patch as well as blanking them off.
Flack
18th Jan 2022 9:37 am
aja4x4
Member Since: 14 Apr 2019
Location: Westbury
Posts: 2462
It's best practise to block both ends, I know it's a bit overkill but if you get an air leak in the egr pipes it will cause a number of fault codes not related to the egr valvesAndrew
D3 2.7tdv6 2005
D4 3.0 SDV6 Commercial died and gone to LR heaven
D5 3.0 SDV6 HSE
18th Jan 2022 11:29 am
Chris1573
Member Since: 12 Feb 2021
Location: Stroud
Posts: 196
Flack wrote:
Yours is a MY2008 , going by your profile you will need a software patch as well as blanking them off.
Flack
Hi Flack, so what does the patch actually do then ? (sorry I'm an inquisitive chap)
18th Jan 2022 11:51 am
Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10485
ECU's magically detect if the EGR's have been blanked or not. And give code P0401 (or some combination of that number) and puts the light on
Detected by change of air flow through the air meter or some other way
18th Jan 2022 1:28 pm
Chris1573
Member Since: 12 Feb 2021
Location: Stroud
Posts: 196
Thanks All
18th Jan 2022 1:37 pm
PROFSR G
Member Since: 06 Mar 2017
Location: Lost
Posts: 4873
Chris1573 wrote:
Thanks Prof. I am thinking of blanking them anyway, am I right in thinking I just need to do the bottom two plates if I am leaving the pipes connected to the throttle body. Along with butterfly removal.
Ideally you need to blank the TB ends as well to prevent any unmetered air flow and remove the butterfly. The valves are monitored by the PCM in a very similar way to command and actuation you see in your GAP tool. An oscillating solenoid motor within the EGR operates a valve which looks similar to an Archimedes screw. The bidirectional nature of the solenoid motor allows the PCM to rotate the valve in either direction thus opening or closing the screw as required. Exhaust gunk and moisture clog up the valve which eventually the solenoid is unable to overcome, or the moisture content fouls the electrical side causing the valves to fail.
A potentiometer style switch is attached to the rear of the motor shaft which provides the PWM feedback to the PCM, as well as actuation commands. You will need a software patch as already stated because your car is an EU4 emissions protocol, which differs from the earlier EU3. The patch is available from Pete Bell at BAS Remaps and is downloaded to your IID via GAP Diagnostics. (Pete & GAP will set this up for you)
If you fit the TB blanks you can leave the long EGR pipes in place, they won't quite reach the TB but the EGR ends will then look OEM and undisturbed!
If you are uploading the file to the car make sure all consumers are turned off, the battery is fully charged, and you have a charger connected whilst the procedure is taking place. yµ (idµ - eAµ) ψ=mψ
18th Jan 2022 3:42 pm
Register
Member Since: 29 Nov 2021
Location: SW London
Posts: 261
Just done mine.
Here's the photos which may help those better informed to explain.
PeteEverything's a hammer.
18th Jan 2022 4:54 pm
Pete K
Member Since: 15 Jan 2016
Location: GL
Posts: 10485
PROFSR G wrote:
The patch is available from Pete Bell at BAS Remaps and is downloaded to your IID via GAP Diagnostics. (Pete & GAP will set this up for you)
If you are uploading the file to the car make sure all consumers are turned off, the battery is fully charged, and you have a charger connected whilst the procedure is taking place.
Of course this costs money.... At least £200 the last time I looked
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