V157 EGR Nozzle Mod to Reduce Clagged Valve OFFICIAL FACTORY MOD

[3T51704x4]

Took some photos during a recent clean of the intake manifold flap valve V157 which was not as bad as others I've seen. The nozzle coats the valve causing reduced movement or even sticking and results in the glow plug light flashing and limp home mode.

Logged codes in address 01 include P012100 and or P211100 and or P211200.

While your valve is soaking in your solution of choice take the time to remove the EGR nozzle to the plastic inlet manifold and rotate it 180 degrees. The nozzle body is mechanically coded (only fits one way round) and needs to be modified with a round file to allow it to fit correctly. Later cars have this done from the factory now, but to check to see if yours has been done, remove the boost pipe and use a mirror or take a photo looking up into the valve.  If you can see a slot facing you, it has not been modified yet.

 

 

Remove 2x T30 from the pipe at the cylinder head

 

 

 

 

Incidentally, if your EGR valve sticks open, the engine will peter out like it's run out of fuel. These are the two bolts to undo and slide a cut to shape drinks can (width of the pipe diameter folded over in two for added durability) down between the gasket and the head , tighten the bolts up again, this then blocks the EGR gas from choking the engine and allows it to start as an emergency repair to get it back home or into a garage.

Then undo the clamp to the nozzle and remove the EGR pipe.

Another 2x T30 and you can withdraw the nozzle.

 

 

Edited 5 July, 2019 by 3T51704x4
Adding Content

[3T51704x4]

 

Clagged nozzle.

 

The nozzle body needs to be filed to allow it to fit the manifold correctly after rotating 180 degrees.

 

 

I used this round file

 

 

Modified nozzle can now be refitted with the opening facing away from the intake manifold flap V157

 

 

Edited 5 July, 2019 by 3T51704x4

[3T51704x4]

 

 

 

Notice the blank plug to prevent the long T30 or short 10mm bolts from dropping into the boost pipe.

Ready to refit V157 which has been soaking in brake cleaner.

When removing these plugs DONT USE ANY TOOLS they just muller the plug Press it inwards slightly, press on the tab with your thumb, then pull back on the housing, not the wires. If you don’t press inwards before pulling outwards, you will need a screwdriver to release it, but as you can see. They come off very easily with the correct technique, this can be applied to all this type of connector weather single or multiple pins.

Edited 6 July, 2019 by 3T51704x4

[3T51704x4]

 

I've seen much worse than this, my car mileage is just under 50K and I haven't had the warning light on, I wanted to do some preventative  

Maintainance.

Keep the electronics cap fee of liquid by suspending the valve.  Scrape the worst off into a plastic bag with a plastic tool then use brake cleaner to finish the job with the tool.

 

 

The flap, its mating surface and the pivot point bushes need to be carbon free or the valve can stick

 

 

Good for another 50K+

Edited 5 July, 2019 by 3T51704x4

[Tech1e]

Great guide, nice work 👍🏻

[chimaera]

Did you find any special trick to remove the flap valve without removing the intake manifold? The last time I looked at doing this I gave up when I couldn't get the flex hose far enough out of the way to pop the valve off.

[superbdreams]

"DONT USE ANY TOOLS they just muller the plug"

muller ??

[langers2k]

25 minutes ago, superbdreams said:

"DONT USE ANY TOOLS they just muller the plug"

muller ??

 

Slang for destroying or wrecking something 😉

[Tech1e]

3 hours ago, chimaera said:

Did you find any special trick to remove the flap valve without removing the intake manifold? The last time I looked at doing this I gave up when I couldn't get the flex hose far enough out of the way to pop the valve off.

 

Normally just pushes down. 

[Tech1e]

Being somewhat inspired I did mine this morning. Wasn’t too bad @45k. 

 

[3T51704x4]

3 hours ago, superbdreams said:

"DONT USE ANY TOOLS they just muller the plug"

muller ??

Muller = damage

[3T51704x4]

4 hours ago, chimaera said:

Did you find any special trick to remove the flap valve without removing the intake manifold? The last time I looked at doing this I gave up when I couldn't get the flex hose far enough out of the way to pop the valve off.

 

Manifold is still in place, just undo both boost hose clips , press the hose in the middle to deflect the hose off the valve, then pull it off the boost pipe. Cover the lower boost pipe straight away as seen in the pictures.

[3T51704x4]

 

 

 

5 hours ago, Tech1e said:

Being somewhat inspired I did mine this morning. Wasn’t too bad @45k. 

 

 

 

 

 

Nice one, I’ve seen them where you can barely see through the valve.

Good to see you wearing gloves too, horrible stuff that carbon, gets everywhere.

Edited 6 July, 2019 by 3T51704x4

[Tech1e]

1 hour ago, 3T51704x4 said:

Good to see you wearing gloves too, horrible stuff that carbon, gets everywhere.

 

25 years in the trade, wouldn’t be without them. 

[3T51704x4]

1 hour ago, Tech1e said:

 

25 years in the trade, wouldn’t be without them. 

Started my apprenticeship 35 years ago with Audi/VW when they were both in the same dealer prior to the split. Can't understand why mechanics don't use gloves or battery operated tools, so much quicker than unwinding a bolt with a ratchet.

I see many videos on Youtube with very good content but watch for three minutes while they labouriously unwind bolts by hand which could be done in a fraction of the time (I always torque critical bolts), and others where the mechanic's hands are caked in grease? Why, no need.

I have a fantastic Snap On torque wrench for doing the torque angle on the CAYC injector bolts, which if you are/were a Skoda M/T will know what I'm talking about.

 

For the record, for others thinking of doing their valve and nozzle, the above mod was not plucked out of the air, it is a current official technical solution from the factory to help prevent the intake manifold flap getting too clagged.

Edited 6 July, 2019 by 3T51704x4

[Tech1e]

I’m actually amazed it isn’t that way anyhow. Makes no logical sense to be to have it pointing at the back of the throttle valve. 

[Tech1e]

21 minutes ago, 3T51704x4 said:

I have a fantastic Snap On torque wrench for doing the torque angle on the CAYC injector bolts, which if you are/were a Skoda M/T will know what I'm talking about. 

 

Me too. Retired out of retailer network in favour of a more profitable career path. Still got my tech angle wrenches though. 

[chimaera]

2 hours ago, Tech1e said:

I’m actually amazed it isn’t that way anyhow. Makes no logical sense to be to have it pointing at the back of the throttle valve. 

It may help with mixing the EGR flow into the main intake charge to point it that way.

[Tech1e]

6 minutes ago, chimaera said:

It may help with mixing the EGR flow into the main intake charge to point it that way.

 

Its possible I guess as a diesel doesn’t create manifold vacuum so requires a depression (such as that behind the throttle plate) to draw the exhaust gas into the intake. 

[chimaera]

1 hour ago, Tech1e said:

 

Its possible I guess as a diesel doesn’t create manifold vacuum so requires a depression (such as that behind the throttle plate) to draw the exhaust gas into the intake. 

It's nothing to do with vacuum (a turbocharged petrol engine won't have much [if any] manifold vacuum either since the turbo is shoving everything down at it), it's the turbulence involved in introducing the EGR against the main intake air flow rather than with it. With the new setup, the EGR will actually be exiting into a low pressure area on the downstream side of the port as it is a stagnation point in the flow and at lower pressure than the bulk flow. In this setup the EGR flow will be a little less likely to mix thoroughly into the main intake flow though I suspect VAG engineers have looked at the tradeoff and decided they can live with it. It's definitely one of the easier CFD models to run.

[Tech1e]

1 minute ago, chimaera said:

It's nothing to do with vacuum (a turbocharged petrol engine won't have much [if any] manifold vacuum either since the turbo is shoving everything down at it), it's the turbulence involved in introducing the EGR against the main intake air flow rather than with it. With the new setup, the EGR will actually be exiting into a low pressure area on the downstream side of the port as it is a stagnation point in the flow and at lower pressure than the bulk flow. In this setup the EGR flow will be a little less likely to mix thoroughly into the main intake flow though I suspect VAG engineers have looked at the tradeoff and decided they can live with it. It's definitely one of the easier CFD models to run.

 

The turbo isn’t operated when EGR is on. The main function of the throttle flap is to create a depression so EGR gas can be drawn into the intake. It also acts as a shut off valve. This is typical for diesel, turbo or otherwise and has been for many years. 

[3T51704x4]

EGR has been a problem with most manufacturers with carbon deposits for years, even with the latest engines running a redesigned system is causing grief, just ask a current T6 owner.

 

Two reasons V157 is fitted to the manifold is to stop the engine more quickly when turning the ignition off and aid with EGR.

If the carbon causes the valve to stick closed, the engine will not start. Luckily, most stick in the open position.

When these valves do stick, they can blow a 15A fuse in the SB fuse box taking out the a/c on the Audi A3.

The complaint was an a/c issue rather than poor running, and the engine used to run on a little when turning the key off.

Edited 6 July, 2019 by 3T51704x4

[jafo]

@3T51704x4

 

Do you know when they started to install it "correctly"??  

[Tech1e]

I don’t think they have done in production. Was just a bulletin for a customer concern. 

[chimaera]

On 07/07/2019 at 05:57, Tech1e said:

I don’t think they have done in production. Was just a bulletin for a customer concern. 

I have a copy of the first issue of the bulletin downloaded from erWin which is dated May 2017, so well after production concluded. It also lists nothing under the 'Production Change'  heading. The bulletin is TPI 2047723 for anyone that wants to find it.