2016 C300 P052E positive crankcase ventilation regulatory valve
Thanks a lot.
There are numerous posts on this topic (one of the best is here https://mbworld.org/forums/c-class-w...ode-p052e.html) and I spent roughly 10 hours between reading them and looking at the car and checking different things. Also made a stop at the dealer and they comp'd me a diagnosis.. with the same result that I read in many of the posts. Nearly $1500 to replace the 274-090-17-29-80 - Intake Line.
I read in one of the posts that someone just simply changed the oil to 5W-30 and the code cleared. My car was due for an oil change so began the quest to find the best MB approved oil (IMO). I landed on using Castrol Edge Extended Performance 5W-30 Advanced Full Synthetic Motor Oil (https://bevo.mercedes-benz.com/bevol..._en.html#close).
Never changed the oil myself or did anything other than tire pressure, but it was time to start! Changed all air filters and the oil and cleared the code immediately, but the code stayed on. Read a little more about that code and found that the car needs to be driven a little for the computer to recognize that the condition no longer exists. Anyway, cleared the code yesterday (6 days after oil change) and the code turned off!
Credit goes to a number of different people adding their posts to the forum. Good luck!




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https://www.nhtsa.gov/report-a-safet...nt-information
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Hey ! did anything ever happen for you ?
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Thanks for the link, I also filed complaint there.
I have 2016 C300 58000 miles with 5W30 oil in last service and the engine light scan returns with P052e code. Its crazy expensive to get fixed and moreover its at the place that's not easy to access. The labor is 4-5 times expensive than the cost of the part itself and local reputed services points don't wanna touch it, too much work/hassle and time consuming job.
This is crazy, if this part supposed to be changed every 40k-50k miles, why they kept it behind the engine deep under. They should be made to make it a recall part. I encourage everyone to file complaint with NHTSA at the link shared.
There is a lack of videos of people fixing C400/C450/C43 on Youtube. I had a few videos up but I took them down after Youtube changed everything.




