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P039B + P0141 + EPC APR STAGE 2 MK7 GTI

DocNotDoctor

New member
Location
Eastern NC
I've been a long time lurker on the forum and wanted to throw out my current situation for all of you to chew on.
For about 2 months had an intermittent P0141 code that would clear on its own but became almost daily a couple of weeks ago. At the same time, noticed a metallic ticking (tappet) sound that was apparent in before and after warm up. No other codes popped. Within a day or two, threw a P039B code with EPC during a 3rd gear pull at around 3700RPM. After turning car off and on, code cleared. The car runs fine at idle and during acceleration up to WOT/4k RPM then EPC with and without P039B. No smoke, no misfire, etc. Ran a few different tanks of 93, no change. Replaced RS7 plugs and coils, no change.
Contacted a local APR dealer and VW repair shop to perform diagnostics. They have performed most of the work on the car in regards to clutch, oil changes, etc. Confirmed codes and they believe tapping noise was a bad hydraulic lifter. Reflashed tune and spoke with APR, not tune related...per APR. They believe tapping noise is coming from cylinder 3 and 4, confirmed with stethoscope. Shop found the knock sensor to be defective (high voltage? I believe) and contributed the P039B (high pressure in cylinder 1) to the fault. They pulled off intake manifold to replace sensor. While there, they found minimal carbon buildup and cleaned as needed. Good news on that part. Knock sensor was replaced but code was still present during test drive and WOT.
Next step is to get to the top of the motor and explore the tapping/knock. Any thoughts? Fuel injectors? I'm replacing the 02 sensor tomorrow, hope to get rid of the P0141. I've searched the forum for the P039B code and didn't find anyone that addressed it. Google search produces little. Any clue why it would pop or if it's correlated with the ticking noise? Thanks all, sorry for the lengthy post. I hope to share my experience and findings.

Current Mods: 2015 MT, APR Stg 2 for 30k miles 93/HO (current 58k), CTS intake, CTS inlet, CTS intercooler, stock DV, APR DP, RSR clutch, RS7 plugs, BFI mounts, stock IS20 and exhaust. Haven't had any issues with the car thus far, regular ~8k oil change (5W-40 Motul). RS7 Plugs and coil packs have 200 miles on them.
 

PacDawg

Drag Race Newbie
Location
Gilroy, CA
^^ I'm no help but I'm APR stage 2 tuned and hear tapping/knocking while my car warms up but no epc or codes. So noises might be normal? I ran 12.5 @113 a couple of weeks ago so car runs fine.
 

DocNotDoctor

New member
Location
Eastern NC
At first I wrote it off as the normal DI sound you would kind of expect. Once I started getting the codes and really investigating it, it's not within the normal sound range. Compare it to tapping that increases with acceleration, top to bottom and it's persistent.
Overall with the plugs, coils, and carbon cleaning the engine sounds great. I don't know if it's psychological but it's much quieter making the ticking that much louder.
 

0bLiViOuS

Go Kart Champion
Location
Orange County
I'd have to hear it, but many users have an occasional knock sound near the timing belt when idling. There's no set pattern but I believe that is just due to the somewhat rough idle of our cars.

Do you think you can get a clip of it, or too hard to hear unless in person?
 

2slowvw

Moderator
Location
VA
Car(s)
2022 Tesla Model 3
OP, just checking in regards to the P0141. You don't have a spacer on any of the 02 sensors right? If so remove the spacer first. Also I see you have Eastern NC listed, I am in Virginia Beach so we could do a potential meet up to listen to the sounds and what not if you want. Seems like it might be a crap shoot if the shop couldn't tell what was causing the tapping.
 

DocNotDoctor

New member
Location
Eastern NC
2slowVW, may end up meeting up with you at some point. I travel up there sometimes but hopefully I'll have the issue resolved, specially the P039B and ticking. I'm running an APR downpipe with no spacer. I've held out putting in the new 02 sensor but that will be in tonight. I wonder how much this could effect the ECM? I'm registered in Florida so no worries with emission so I've just written it off for so long. .
Ob, I'll put up a video tonight of the ticking. It's gotten pretty quite since the recent oil change and I've tried Liqui Moly tappet additive to see if that effects it....could be but you know how the mind can play tricks.
I'm currently doing some logs but to be honest I'm pretty much an idiot once it gets down to the intricate logging and diagnostics. Any suggestions?
Thank you all who have replied thus far
 

2slowvw

Moderator
Location
VA
Car(s)
2022 Tesla Model 3
2slowVW, may end up meeting up with you at some point. I travel up there sometimes but hopefully I'll have the issue resolved, specially the P039B and ticking. I'm running an APR downpipe with no spacer. I've held out putting in the new 02 sensor but that will be in tonight. I wonder how much this could effect the ECM? I'm registered in Florida so no worries with emission so I've just written it off for so long. .
Ob, I'll put up a video tonight of the ticking. It's gotten pretty quite since the recent oil change and I've tried Liqui Moly tappet additive to see if that effects it....could be but you know how the mind can play tricks.
I'm currently doing some logs but to be honest I'm pretty much an idiot once it gets down to the intricate logging and diagnostics. Any suggestions?
Thank you all who have replied thus far

If you are indeed stage 2, do not put a spacer on the 02 sensor. I've seen on the forums people who have had the cel on in stage 2 and when they took their spacer off it went away. So leave the spacer off IMO.

Since the car can tell if the pressure in cylinder 1 is too high, then you must be able to read a block with VCDS and compare the pressure vales in that to the other cylinders. I tried doing a quick search for you to see if I can find where that would be located but have not come up with anything yet.

Your local shop cleared the pressure too high code and it came back again?
 

Mk7GTl

Go Kart Champion
Location
USA
I have a tapping sound too when the engine is cold for several minutes after the sai is done working. At 1500 miles the dealer replaced the cylinder head thinking it was a bad lifter and it didn't resolve anything and I regret having them touch my engine at such a low mileage. I think its normal because I heard my friends virgin 2016 GTI making a tapping/knocking sound when he initially started it up when the engine was cold. It goes away after a minute or two... its really stupid and sounds unhealthy. The noise does not increase with rpm.


Record a video?
 

0bLiViOuS

Go Kart Champion
Location
Orange County
Ya I'm not sure what you might be able to log specifically. It's an odd issue and like 2slow said, there has to be a measuring block in VCDS if the ECU can differentiate the cylinder pressure. Only other thing I can think is PCV bad?
 

DocNotDoctor

New member
Location
Eastern NC
Ya I'm not sure what you might be able to log specifically. It's an odd issue and like 2slow said, there has to be a measuring block in VCDS if the ECU can differentiate the cylinder pressure. Only other thing I can think is PCV bad?

I'm getting more and more suspicious that this could be a bad PCV valve. i don't have a fluctuation in idle or whistle noise but it seems as though this could manifest itself in many ways. Any suggestions on how to check it?
If I accelerate slowly, 25% throttle, the car will continue up to redline no issues. If I accelerate slowly up to 4K rpm then floor it, i have no EPC. Thoughts?
 

DocNotDoctor

New member
Location
Eastern NC
Ran some liqui moly engine flush as recommended by shop. They thought it was the knock sensor being kicked on by a hydraulic lifter, which could explain the noise (ticking). It worked. Followed everything up with an 5W-40 LM oil change and I no longer have codes or tick. Full WOT and nothing. I'm happy they didn't have to open anything up and I was surprised the LiquiMoly worked. I know it's questionable but no problems here. Engine sounds smooth.
 

Quebster

Autocross Newbie
Location
Dallas, Tx
Ran some liqui moly engine flush as recommended by shop. They thought it was the knock sensor being kicked on by a hydraulic lifter, which could explain the noise (ticking). It worked. Followed everything up with an 5W-40 LM oil change and I no longer have codes or tick. Full WOT and nothing. I'm happy they didn't have to open anything up and I was surprised the LiquiMoly worked. I know it's questionable but no problems here. Engine sounds smooth.


Hey Doc... this fixed your issue for good? I seem to be having something similar minus the P0141. I get the P039B on occasion, and have noticed an obnoxiously loud clicking which I thought was just the HPFP. It was loud ever since we built the engine and I thought maybe it had to do with the oil I was using during break-in. But now I'm back on Motul 5w-40 and it still seems to be a bit loud.
 

DocNotDoctor

New member
Location
Eastern NC
Hey Doc... this fixed your issue for good? I seem to be having something similar minus the P0141. I get the P039B on occasion, and have noticed an obnoxiously loud clicking which I thought was just the HPFP. It was loud ever since we built the engine and I thought maybe it had to do with the oil I was using during break-in. But now I'm back on Motul 5w-40 and it still seems to be a bit loud.


The loud clicking issue has never returned. Haven’t had a fault or code since I flushed it, wasn’t immediate but approx 500 miles after the flush.. Use the engine flush and oil treatment from LM. I continue to use the oil treatment after every change. My gut feeling is that I stuck with OEM oil for too long after going stage 2, I’m sitting at 90k miles roght now (70k stage 2). Let me know how it goes. I didn’t receive much feedback from the forum so I’m interested to see if anyone else has the issue. Good luck
 
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