CoronaX

Looking for some guidance to resolve P052E(Positive Crankcase Vent Valve Performance) CEL on my CLA250. CEL has been ON and OFF for last month or so. My car has currently 100K on it.

Any schematics, part number or guidance would be much appreciated.

Cheers!

ckulaksiz

Were you able to fix this issue? I am having the same problem.
Thanks!

CoronaX

No I haven't been able to fix it, still running with CEL for last 6 months since its intermittent. I believe I understand the issue... basically there are two PCV valves, one for the partial load(city driving<1000rpm) and the other one for high load(highway driving>2000rpm). I have noticed the CEL clears itself when I get two high load trips and it turns back ON when I drive in the city. Here's is the PN#2700901529 (air intake line) you need to get changed to fix this stupid issue. Unfortunately its an assembly and costs around $500, which doesn't make sense since its a tiny valve which needs to be replaced.

ckulaksiz

Thank you for the update! Is this the valve?

CoronaX

http://autocats.ws/manual/sdmedia/me...001_003_en.pdf

CoronaX

Let me know if you are able to fix the issue.

ckulaksiz

Thank you again! I guess intake manifold needs to be removed to get to the oil seoparator.

Mark Medynski

I just finished getting the valve unstuck...It took about 30mins...mostly because I had to do it it blind as the "vent valve # 3" is not the back of the intake manifold...All you have to do is to disconnect the rubber hose "purge line #4" and spray brake clean and let that dry...then fill the tube with WD40...When the level in the hose drops....you know the valve is unstuck....Pop the hose back on to the intake manifold and Bob's your Uncle!...Clear the code with your scanner and have a Beer...Job well done....Cheers

Trevor D

Wow, good job! So, you popped the top end off of the rubber hose purge line #4 then sprayed brake clean inside of it, let it dry, then filled it with WD 40? And never touched the PCV valve itself? Apparently the shop charges about 10 hours to replace the valve..

I have a 2017 GLA250 with the P052E PCV valve code up. Is there any way someone can share the engine drawing for it?

Mark Medynski

Hey Trevor, in fact Mercedes charges 10 hours to replace the oil separator #2...as the vent valve is not sold separately...all the tubes,valves and separator are sold as one assembly...So in my case my Icarsoft code reader told me the vent valve #3 was stuck....before shelling out $800 for the whole assembly and 10hrs of time...I started by cleaning the stuck valve...

Trevor D

Hi, thanks for the reply. Does your iCarsoft reader read the Mercedes specific codes? Did it come up with p052e and another Mercedes code for vent valve #3? I have a reader but it will only do generic obd2 codes so only got the p052e.

Is this the one you have?


Thanks for sharing Mark!

Mark Medynski

Yes, That's the one I have...It reads live data...for instance...The voltage at the fuel pump while the car is running...Temp sensors..to name a few...It is designed for Mercedes and reads specific MB codes...Don't take my word for it...Read the reviews...It tagged the P052E and explains what is causing the issue...If I remember correctly it said that the vent valve was stuck and vent pressure was out of accepted value....something like that...

Xpsionic

Hi Mark, is it possible to take that valve off of line #4 and line #3 so it's easier to clean it off the vehicle? Or is that not really feasible?

Thanks for your posts btw, really helpful!

Mark Medynski

I'm sure it's possible as line 4 is just a crimped on rubber hose...but you will have to find a way to refit the second line as I am not sure how it's attached to the valve...and the electrical connector must also be detached...

Xpsionic

i see, how's the repair holding up? I watched a video on the car wizard's channel on YouTube, he tried cleaning/clearing it but it wasn't quite enough in his case.

Mark Medynski

Yes...I also saw the Wizard's post...In his case he has to offer a more definite repair to his paying customers...the first time I cleaned the valve it did re-code after about a week...but it was not fully stuck as I was able to clear the code....as apposed to the first time it got stuck I could not clear it...So I popped off the hose that is connected to the intake...filled it with WD40...reconnected it to the intake...and let it soak over night...When my girlfriend went out in the morning to go shopping...I followed her out to clear the code....but when she started the car...the code was gone....I knew then that I was on the right track to fully cleaning it...

sn202020

I had many p052e with 2017 GLC300, and found your cleaning today. So I disassembled intercooler, and still don't know where is the #4.
​​
Can you find at my picture?

sn202020

I think this hose is from the rectangle box.
Behind of the throttle butterfly, around the engine oil dipstick.

I put some Seafoam.

sn202020

Seafoam 50 cc, then driving 15km made another p052e.

Texas CLA

Question here as I have the same code and I would like to follow this procedure. You spray brake cleaner in the #4 line and then once that is dried I am not sure I follow. When you state fill the tube do you mean the same #4 line of something different. And when the WD-40 is gone and that means the valve is no longer stuck, where does the WD-40 go? Please tell me not in the oil.

sn202020

I tell you it goes to the engine oil pan thru the oil separator,s bottom return hole.

Oil is more than 6 liters in the engine. So adding 100 ~300 ml liquid is not too bad. I guess 5w40 becomes like 5w35 or 5w30.

it did not fix my p052e code completely. but less frequently code comes back.
Even though I tried 3 times.

Texas CLA

My issue is that W40 is mmuch lighter than oil and would sit on top like water causing aeration and foaming and would lead to sludge. After some internet research, it shouldn't be a major issue but still a risk.

sn202020

then don't do, or change the oil earlier.
I change it myself costing only $30 for oil.

FLAKKO-AMG-CLA

this is how much Mercedes is charging me to get this code fix. But funny story. I took car in 1st time lights all over dashboard. They said (battery low voltage ⚡) FIXED. Same day driving home lights on dashboard once again. 2 time at Mercedes. They said. A wire was loose. FIXED. next day driving home all lights back on on DASHBOARD. CHECK ENGINE LIGHT ON AS WELL. now this is what they told me, my issue is now.

sub786sub

Very informative post. The question is how to prevent this from happening in the first place. Should we add any oil catch can before the PCV?