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  #11  
Old 30th July 2018, 05:31 PM
ainarssems ainarssems is offline
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I think you are talking about anti shudder valve. It only has two positions open and closed, it does not participate in airflow regulation, just cuts air supply when you turn ignition off so that you have smoother engine stop as it does not have to compress air in cylinders. Added benefit is that it eliminates possible engine run away.
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  #12  
Old 30th July 2018, 06:43 PM
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Hey great info cheers,I wish I had VCDS to test it to be honest to test it, it could be my imagination but does seem to be a small improvement, however like you say it could be compensating for this restriction. I agree a full blank might be a good test even if it does put the EML light on the plates only 3 worth a stab, I know a more permanent solution would be mapping it out just thought I'd give it a go

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Originally Posted by ainarssems View Post
I am not sure these restrictor plates do much or anything at all on modern engines which determine how much EGR is open based on measured airflow. If something is blocking EGR flow and metered airflow is too high ECU will just open EGR valve more, if the air flow or EGR duty cycle is out of tolerance sit will throw error code. Have a look at measuring blocks in VCDS for specified and actual airflow and EGR duty cycle. If the specified and actual airflow ar close together you have not made much difference on amount of EGR entering engine, if the EGR duty cycle % is high it means ECU is opening EGR valve more to meet the specifications. It would have been great for comparison if you had a log before and after fitting plate.

Restrictor plates were working for older cars like 1.9TDI where EGR was only mapped in ECU as duty cycle and not as specified airflow on newer cars. Basically on old cars ECU just looked at the map and choose EGR duty cycle depending on rpm and injected fuel quantity and did not care about airflow, on newer cars it looks up required airflow depending on rpm and injected quantity and then adjusts EGR valve duty cycle to meet specified airflow value.

You can turn off or reduce EGR by remapping ECU and on some ECUs you can adjust it through adaptation with VCDS as well.
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Audi A8 D3 2006 3.0TDI Quattro Sport
Added: Bluespark CR 1, two new front tyres, 20mm hubcentric spacers on the rear, rear audi number plate surround with new plates, new Bosch Aero wipers, Standardigital TV, Bose sound system, heated seats, sports suspension, 20x9 9 spoke RS4 style rims, audi aluminium valve caps, bumper resprayed, mirrors sprayed, a wash every few weeks

Future mods: Turbo uprgade possibly and sort out those downturned exhausts only a mother could love 😂
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  #13  
Old 30th July 2018, 06:48 PM
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Hey mate, yes the manifold muck concerned me , its like feeding the engine its own poop, I am temped as well to clean the intake manifold but It looks very mess and the Mrs would go off it! I might ask local garage how much it would be to clean
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Originally Posted by snapdragon View Post
TBH, if less EGR gas is entering the intake than is specified (demanded) by the ECU, you will get an 001025 - EGR System P0401 - 002 - Insufficient Flow code. It is measured by the drop in the the airflow meter reading that happens when the EGR allows unmetered exhaust gas into the intake and corroborated by the O2 sensor in the pre-catalyst on 06-on models which looks for a small enrichment.
This is continually monitored by the ECU and the EGR valve position modulated to keep it within tolerance. I suspect the restriction is not adequate to reduce it enough to trigger.

You should get better economy if anything and cleaner intake, but it may be noisier coming off the overrun as the EGR's richer mixture makes for a quieter combustion.
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Audi A8 D3 2006 3.0TDI Quattro Sport
Added: Bluespark CR 1, two new front tyres, 20mm hubcentric spacers on the rear, rear audi number plate surround with new plates, new Bosch Aero wipers, Standardigital TV, Bose sound system, heated seats, sports suspension, 20x9 9 spoke RS4 style rims, audi aluminium valve caps, bumper resprayed, mirrors sprayed, a wash every few weeks

Future mods: Turbo uprgade possibly and sort out those downturned exhausts only a mother could love 😂
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  #14  
Old 1st August 2018, 09:00 PM
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Quote:
Originally Posted by ainarssems View Post
i think you are talking about anti shudder valve..
I am but it is variable and is also for EGR assistance as described in the SSP...
Click image for larger version

Name:	Screenshot 2018-08-01 at 22.13.20.png
Views:	43
Size:	990.4 KB
ID:	19873
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  #15  
Old 2nd August 2018, 05:41 AM
ainarssems ainarssems is offline
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Ahh.. must be an update on newer cars, looks like it's electric driven. Older engines just had vacuum operated on/off valve.
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  #16  
Old 2nd August 2018, 09:15 PM
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Don't suppose if you know if removing the upper intake manifold it just slips out after unbolting? Was thinking of giving it a good cleaning, I hope its that easy, I really do
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I am but it is variable and is also for EGR assistance as described in the SSP...
Attachment 19873
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Jonny P
Audi A8 D3 2006 3.0TDI Quattro Sport
Added: Bluespark CR 1, two new front tyres, 20mm hubcentric spacers on the rear, rear audi number plate surround with new plates, new Bosch Aero wipers, Standardigital TV, Bose sound system, heated seats, sports suspension, 20x9 9 spoke RS4 style rims, audi aluminium valve caps, bumper resprayed, mirrors sprayed, a wash every few weeks

Future mods: Turbo uprgade possibly and sort out those downturned exhausts only a mother could love 😂
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  #17  
Old 6th August 2018, 10:09 AM
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Originally Posted by jonnypym123 View Post
Don't suppose if you know if removing the upper intake manifold it just slips out after unbolting? Was thinking of giving it a good cleaning, I hope its that easy, I really do
I have had it off a couple of times using the audi service manual instructions which were sufficient. Worst thing is removing fuel pipes and all the vacuum pipes and wires. My vacuum pipes broke when unclipping- they had turned to liquorice and new ones were 70-80! Take some photos showing the routing and clip positions as what is above and below each other and where pipes cross etc...
Some of the screws are long, some short, so mark with a paint pen or some other way of remembering. The lower intakes were the really sooty ones, as well as the ports in the head, some were about 75% blocked. I used the pressure washer on the removed plastic parts and sticky stuff remover and a roll of paper towel on the heads, a lot of carbon fell in but I was careful not too much liquid went in. Used original gaskets the first time they were in good shape, and new ones the second time.

Didn't notice any difference whatsover in mpg or performance afterwards
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  #18  
Old 6th August 2018, 04:35 PM
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Cheers, snapdragon great advice I will definately take some photos/markings wouldn't have thought of doing that I'm not that clever usually , that what I was worried about removing the fuel pipes, vacuum pipes and wires it looked scary. I was thinking about over cleaner and pressure washing the upper manifold and leaving to dry. Lower I wasn't sure how to deal with but the paper towels might be an option. No noticeable performance increase damn! It's making me think is it worth doing haha
Quote:
Originally Posted by snapdragon View Post
I have had it off a couple of times using the audi service manual instructions which were sufficient. Worst thing is removing fuel pipes and all the vacuum pipes and wires. My vacuum pipes broke when unclipping- they had turned to liquorice and new ones were 70-80! Take some photos showing the routing and clip positions as what is above and below each other and where pipes cross etc...
Some of the screws are long, some short, so mark with a paint pen or some other way of remembering. The lower intakes were the really sooty ones, as well as the ports in the head, some were about 75% blocked. I used the pressure washer on the removed plastic parts and sticky stuff remover and a roll of paper towel on the heads, a lot of carbon fell in but I was careful not too much liquid went in. Used original gaskets the first time they were in good shape, and new ones the second time.

Didn't notice any difference whatsover in mpg or performance afterwards
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Jonny P
Audi A8 D3 2006 3.0TDI Quattro Sport
Added: Bluespark CR 1, two new front tyres, 20mm hubcentric spacers on the rear, rear audi number plate surround with new plates, new Bosch Aero wipers, Standardigital TV, Bose sound system, heated seats, sports suspension, 20x9 9 spoke RS4 style rims, audi aluminium valve caps, bumper resprayed, mirrors sprayed, a wash every few weeks

Future mods: Turbo uprgade possibly and sort out those downturned exhausts only a mother could love 😂
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