I previously had rough idle when my car threw a P052E00 for the PCV in 2021 - the dealer replaced only the breather hose as it was an extended warranty job. No issues until the past month

ran VCDS on my 2016 audi sq5 and have the following:20136 - PCV Valve Malfunction
P052E 00 [01100000] - -
Intermittent - Not Confirmed - Tested Since Memory Clear
Freeze Frame:
Fault Priority: 2
Fault Frequency: 1
Mileage: 84783 km
Date: 2024.09.05

My coolant was at the min level when it got serviced 9/12 and was told to replace the PCV. No sources of coolant loss was found anywhere by the tech.

The coolant level is already down to min 10 days later and i'm not seeing any coolant under the s/c - the waterpump - coolant hoses that i can visually inspect myself.

The car currently runs great - no CEL - no rough idle etc

Question: Does this really sound like a bad PCV? Would the one Intermittent code be enough to go "a ha - that's it" Anywhere else i should look to determine coolant loss? I really hope ist not cracked and letting coolant into the oil/engine but no way to check without draining it

thoughts?


edit: For anyone reading this going Hey i have same issue! here's the update:
1. searched high and low for any sign of coolant for atleast an hour while car running/up to temp/heat on. nothing.
2. car automatically cleared the 'soft code' after X amount of days and hasn't coem back. As stated below, that code is more for the valve for the breather hose - most likely was stuck for a hot second - going to use some lubricant to free up any gunk. car runs normally.
3. low coolant issue - had the car looked at by the audi mechanic - they also found no signs of leakage and the pressure test (~3 hours they said) found no issues as well/level didn't decrease.

My take aways: i live in colorado and use this car mostly for my mountain adventures - my only conclusion is the high elevation and hotter than normal year has caused some evaporation.

 

If coolant is entering the oil then beige foamy sludge should begin to appear on the inside of the oil fill cap opening. Obviously stop driving and repair if you see this.

Since you looked top side and found nothing then pull the lower engine cover and look around from underneath for coolant loss. You should see pink and white track marks from leaking coolant. Look close into the left front corner of the bumper cover as the electric pump and several hose connections live there. I once had a slow coolant leak on a 3.0T at the front lower cooler connection that was not visible until I pulled the front bumper cover.

I think you have 2 separate issues. Your mileage is low enough that the PCV Oil Separator *should* not have failed. The P052E DTC is not the PCV itself but rather an air line with an ECU actuated valve connected back to the intake. You could try a suck and blow test on the rubber hose attached to the backside of the intake tube on the firewall side. Mine had air flowing in both directions so my valve was stuck open at 60,000KM and produced P052E DTC. I simply sprayed a couple shots of quality inert lubricating penetrant into the rubber tube connected to the valve and it freed up the piston. I have yet to test drive and confirm as I have it apart for other work atm.

Check here for more P052E info:

https://www.audiworld.com/forums/q5-...04%5D-3026579/

 

thank you! I still need to look under the engine myself - but after replacing my rear brakes i noticed the code is entirely gone. I'm assuming since it never showed back up/was confirmed the car auto cleared it after 20 days of driving. Car still drives beautifully/no rough idle. There is strong vacuum when removing the oil fill cap - unsure if that is good or bad...as i'm unsure how strong the vacuum (which it should!) feel. Probably a bad 'test' people spout on the forums.

It's all very confusing - thanks for the details!

 

I'd need more information to do this test as i'm unsure which of the many vacuum lines it would be...i assume do it while the car isn't running haha.'

edit: i'm an idiot - the literal plastic intake tube that connects to TB - the one tube connected on firewall side. as FYI for other dummies like me

double edit: did suck/blow test - could blow/suck no problem. assuming thats an issue?

 

Yes that is an issue. You have confirmed the piston on the ECU controlled valve is stuck open.