P00AF00 Wastegate

[madwazzabi]

I'm not sure if further insight can be provided on this issue but I am having the exact same problem although engine is completely stock.

Due to the whole Covid19 situation, the GTI has been parked for the past few months. I've ended up putting fuel stabilizer and used a ctek battery charger prior to leaving it in this state (wife's lincoln mkx is the children hauler and became the de-facto daily driver). I thought it would be a good idea to still drive the GTI around the block after sitting for about 4 weeks and I ended up getting EPC with the P00AF00 error. Wanted to see if there was anyway on OBD11 to actually exercise the actuator to observe movement of the arm while the car is stationary?

Symptoms are,
- charge pressure actuator actual position starts off at around 12.5% and is initially stuck here which I believe causes the "static" EPC.
- charge pressure actuator specified position keeps asking for 95%
- I don't go into limp mode as I get full range of RPMs.
- I get some level of boost but I can't confirm if its the correct PSI that the engine is looking for. (not safe to check boost on phone app while driving...)
- first time I took the car out from sitting for 4 weeks, I got the oil up to temperature and then started to push the car. As I do this I see my charge pressure actuator actual position value slowly creep up in value and in about 20km of various forms of driving able to get it up to the 95% threshold and am able to reset the EPC from OBD11 and EPC stays off for the rest of the night.

Tried again a couple of weeks later and the same EPC pops up, decided not to retry the whole driving thing if this is going to be reoccuring. Decided to spray liquid wrench on the wastegate actuator arm for a few days like how the other forums suggest. Tried for a third time last week. No dice.

01 Engine
System description: 2.0l R4 TFSI
Software number: 5G0906259A
Software version: 0006
Hardware number: 06K907425B
Hardware version: H13
ODX name: EV_ECM20TFS0205G0906259A
ODX version: 001008
Long coding: 091D00122424002F1000
Trouble codes:
P00AF00 - Turbocharger/Supercharger Boost Control "A" Module Performance
static
Date: 2020-07-23 22:12:47
Mileage: 58684 km
Priority: 2
Malfunction frequency counter: 2
Unlearning counter: 255
Engine speed: 1889.50 1/min
Normed load value: 39.6 %
Vehicle speed: 41 km/h
Coolant temperature: 66 °C
Intake air temperature: 26 °C
Ambient air pressure: 1000 mbar
Voltage terminal 30: 13.496 V
Dynamic environmental data: 2096283EAA003EA844203EA615E33EA70E2D3EA921823EAB6000180106

This likely won't get resolved until I get marching orders to start going back to the office for work but looking to see if I should start preparing to buy a new wastegate actuator or worse, a new turbo...

 

[madwazzabi]

Success!

So an update in case someone else ends up letting their car sit for an extended time and end up with a P00AF00 error code when they finally take their car out for a spin...

A more expanded explanation of my error is as follows,
- my wastegate started off seized at about 13% position, so almost closed. Couldn't pull the actuator arm for the life of me.
- Start the car, if any previous errors were cleared you will not get an EPC. EPC won't kick in until coolant up to temperature and you push the car enough to require boost.
- EPC comes on and it is a P00AF00 static error alone with no other error associated to the engine. Live data should show actuator specified value should go to 95% and your actual value will be stuck at wherever it may be.
- EPC will return no matter how many times you clear this error... obviously. Don't know if the fact that mine was binded at about 13% that limp mode didn't kick in limiting RPMs. I had full range. Just that my car drove with no boost or at least boost with a lack of pressure control.
- If wastegate actual position live data changes at all during hard driving you have some inkling of hope it'll free itself out that night. First time out after letting the car sit for a month it took about 30 minutes of hard driving and each hard throttle push made my wastegate actual position move about 5-7% closer to 95%. Once you reach 95% I cleared the error and all was happy. Then I let my car sit again for another 2 weeks and it is seized again...
- This time stuck at 12% no matter what I did. Spent 2 weeks spraying WD40 on the linkage at the joint where the wastegate enters the turbo and a couple of love taps from a hammer. Still couldn't pull the actuator arm for the life of me.
- Last night drove it again, but like the first time out after a long time sitting, the actual value reading slowing crept to 95% but this time 15-20% each hard throttle push.
- Cleared the EPC and good to go. Can pull the actuator arm out, but it doesn't spring back so I have to push it back to default position (not sure if this will be an issue in the future...).

Now I've slathered the joint with nickel anti seize.
Lessons learned,
- 99% chance that the wastegate flapper itself is NOT seized and most likely the pivot joint just outside the turbo. If you have PP like I do, avoid taking off the downpipe mounting nuts because the one near the O2 sensor is a *#&$(*#&(*$)(#)*$.
- Everyone says 13mm but I found 1/2" socket fit these nuts like a glove. 13mm helped in approaching at an angle at the risk of rounding the nut... 13mm socket only helped me for the nut near the O2 sensor...
- Anyone who is letting their car sit for any long period of time and haven't done the nickel anti seize should add lubrication of this part as things to do when storing the car away (battery tender, fuel stabilizer, etc.) This is especially important if you live somewhere that have humid days.

TL : DR, there is hope to fix a seized wastegate by using penetrating oil on the linkages before taking the car out for spin to allow the actuator to torque its way free. I would say if you let your car sit for over a month you should include lubricating this joint this as prep prior to starting using it again just to reduce the risk of breaking your actuator as this is likely what would cause the actuator spring to fail as seen on another thread. If you wanted an excuse to upgrade your turbo, sure let your car sit for a month...

 

[kingkhan]

Do you have a picture of where you sprayed the penetrating oil?

 

[Diggs24]

At the joint.

 

[madwazzabi]

To be exact this is the location I kept spraying, (not my picture but I added the arrow).

Small squirt every day for two weeks, recommend spray only with straw attachment.

 

[THEREALVRT]

thats not were it seizes up

To be exact this is the location I kept spraying, (not my picture but I added the arrow).

View attachment 184824

Small squirt every day for two weeks, recommend spray only with straw attachment.

thats not were it seizes, all of the turbos i do wastegate repairs on are seized to the left of th pink arrow. The part were the rod threads into seizes to the arm the attaches to the flapper. They are seized so tightly that they cannot be moved by hand. they are stuck at an angle an even with the parts off the turbo and on the bench, if i hit them with a hammer they don't move

 

[madwazzabi]

Every single time? Well I was only describing my sequence of events. It's plausible that my squirts had enough overspray to drip down to that joint as well but I did use a paper towel there each time to catch any extra to prevent any dripping to parts below. Or possibly my light taps may have done the loosening but my oil application was primarily at the location I showed at the purple arrow.

The joint that I had identified had obvious signs of corrosion. I don't have a before picture anymore but see attached shows the obvious dark maroon matting of oil eating away at the rust. Yes there is a little bit of the same too on the pin of the joint that you say where your experience says it should be, but it just wasn't conclusive. I contemplated removing the C clip and pin but figured I would risk losing the C clip and that it would be impossible for me to put it back.

I would have suspected the joint that goes into the turbo would be more prone to corrosion due to being exposed to exhaust gasses.

thats not were it seizes up

thats not were it seizes, all of the turbos i do wastegate repairs on are seized to the left of th pink arrow. The part were the rod threads into seizes to the arm the attaches to the flapper. They are seized so tightly that they cannot be moved by hand. they are stuck at an angle an even with the parts off the turbo and on the bench, if i hit them with a hammer they don't move

 

[THEREALVRT]

Every single time? Well I was only describing my sequence of events. It's plausible that my squirts had enough overspray to drip down to that joint as well but I did use a paper towel there each time to catch any extra to prevent any dripping to parts below. Or possibly my light taps may have done the loosening but my oil application was primarily at the location I showed at the purple arrow.

The joint that I had identified had obvious signs of corrosion. I don't have a before picture anymore but see attached shows the obvious dark maroon matting of oil eating away at the rust. Yes there is a little bit of the same too on the pin of the joint that you say where your experience says it should be, but it just wasn't conclusive. I contemplated removing the C clip and pin but figured I would risk losing the C clip and that it would be impossible for me to put it back.

View attachment 184830

I would have suspected the joint that goes into the turbo would be more prone to corrosion due to being exposed to exhaust gasses.

yes, every single time is the were the rod end pivot point

 

[norsairius]

Geeze - this is maybe the 4th or 5th report of something like this in the past month? Makes sense we're seeing this more since people aren't driving much due to the pandemic. I can't believe this happens though just from letting the cars sit - seems like something that shouldn't cause issues like this on such a critical part, but maybe there's more to this.

Makes me paranoid about letting the car sit for anything longer than a few days or even a week! Edit: I know that in all likelihood the car would probably be fine, it seems it's longer periods of sitting without being driven that seems to lead to this coming up. I wonder what else there might be to this though.

 

[madwazzabi]

Yeah I know, and it seems like it is going to come up as a problem more frequently. GolfDave had a good explanation that the corrosion could be from dissimilar metals used in the linkages. However, ppl keep saying it is that joint at the end of the actuator rod and only the joint and nothing else. Well if that is true, isn't the fix really really simple? IS12, IS20, and IS38 actuator rod end pivot point seem to be identical in using a pin and C clip. Replace that pin and C clip with something that won't corrode to the point of seizing. Heck, if you can take off the turbo, take the C clip off and use a vice grip/pry bar on the pin. Since the forces are perpendicular you would have no risk of damaging the actuator.

The main thing is, catch this issue before the actuator fails. If this pin keeps rusting every humid day and your actuator keeps taking a hit every time you drive it after, then maybe yeah, those nylon teeth aren't going to last long...

I don't see this joint being high stress, but it does need to withstand high heat. Possibly replace this pin with a nut and bolt suitable for contact with (brass?) but in a way that doesn't introduce wiggle/rattle to your wastegate?

 

[norsairius]

Well, I suppose if we see this come up enough we could hopefully see a TSB or something come through. I'm not holding my breath though.

Edit: For those who do get this issue, it might be worth submitting a complaint with the NHTSA if this has impacted your ability to safely operate the vehicle in any way: https://www-odi.nhtsa.dot.gov/VehicleComplaint/

 

[Murmulis8]

My problem was broken vacuumpipe on intake manifold. There is turbocharger regulator, easy to break.

 

[SamGTIMK7]

Seem to have been hit with the same issue myself. Car hasn’t been getting used as much due to COVID and new job means I have a truck to use everyday. Car has done 4K miles between MOT’s and I’m hit with this fault. So yous recommend taking off the DP and checking the operation of the actuator and spraying some anti seize on the joint?

 

[madwazzabi]

Removing the DP not necessary for just reaching the wastegate actuator rod and linkages.

First thing I would do this time around is simply reach the linkages from above (not my pic but I added the arrow to show approximately where to reach).

Normal operation I found is that you should be pull the rod back and forth without too much resistance and it should feel like you're rolling the gears of an electric servo. If you can't pull it back under your own force it is seized and a can of penetrating oil with a straw should be able to get oil where you need it. spray at spots as described in earlier posts. Repeat for a few days.

If it breaks free, then apply the anti seize.

Seem to have been hit with the same issue myself. Car hasn’t been getting used as much due to COVID and new job means I have a truck to use everyday. Car has done 4K miles between MOT’s and I’m hit with this fault. So yous recommend taking off the DP and checking the operation of the actuator and spraying some anti seize on the joint?

 

[SamGTIMK7]

I’ll give that a try, thank you for the quick response!