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M264 Engines - How do you remove the PCV Hose on the Crankcase Vent Valve?
Help! In the process of replacing a cracked plastic coolant pipe on my wife's 2019 Mercedes C300 (M264 engine), the plastic hose that is attached to the Crankcase Vent valve/oil separator part snapped right at the connector. I bought a brand new unit because it was cheaper than buying just the hose used off ebay, and I can't figure out a way to remove this hose without breaking it. Does anybody have any ideas or have done this before? It can freely rotate and there seems to be a white clip that you can pry off, but when I did it on the car, that clip snapped, and then in the process of prying out that connector, it snapped as well. I tried gluing/taping it back together, but it doesn't make a good enough seal and throws a Check Engine Light code of P052E error. Some advice would be greatly appreciated.
Thank you for your help! And yes, I've been searching youtube, but can't find any helpful videos on someone working on the M264 engines. That video you posted is for the M274 engine, which is a different motor from what I have unfortunately. Sadly, not a lot of information out there from searching the web. I am not sure what I should be typing to find what I need.
Just an informational update for those wondering what ended up happening or if they ran into the same issue. That hose connector does not come off without breaking it, so the entire PCV had to be replaced. The labor to do this is extreme because you have to remove a lot of components to get it out, so hopefully you don't run into that issue.
I made an account just to chime in case any one runs into this. I could not get this connector off without breaking it but I did NOT break the rest of the housing. I used a pick tool and tried to carefully lift the little grey tab but it just would not budge at all. Eventually I broke the tab and fished out the ring. Then I grabbed some pliers and carefully pulled it off. From there, I cut the PCV hose off the housing and used 6mm ID hose and slipped it on. I then used a Dorman 800-197 - 10mm PCV connector with a barbed fitting. It's the EXACT same size as the other PCV connectors under the manifold. I test fitted using the other end of the PCV hose to make sure it would fit and it did. I had one hell of a time slipping on 6mm ID silicone tubing onto the larger barbed fitting on the PCV connector but somehow I managed, I then used a larger ID hose I had and slipped it over that just to be extra secure. I'm a Saab guy and have replaced MANY PCV connectors this way. In hindsight, maybe use a barbed reducer so you can use larger silicone hose on one end and smaller on the other, or maybe go up a size like 7mm ID. I'm sure there's some tool or something that would remove that Kayser fitting but I couldn't find much info on it other than this post.
I think it's insane this hose isn't sold separately. As far as I could tell, there are some on Aliexpress using the generic connector type but that would have taken way too long and would be questionable quality like all spares are now. This at least saves you from replacing the entire system. This broke in the middle of replacing the coolant outlet pipe with the metal one.
Last edited by Ambiwlans; Mar 10, 2026 at 11:40 PM.
Nice work Ambi, I was searching everywhere for that freaking connector, I am glad you were able to find it because that saved you a lot of headache. This is so incredibly poorly designed, it's hard to think of any legit engineer coming up with such a terrible design (I am a mechanical engineer myself) and I see no reason in why they did it like this. Overall, I resolved the problem replacing it, but boy was it difficult as hell, I am glad you're sharing an alternative option.
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