Over in the Y51 area, one of our posters with an M56 does collect enough oil for it to be a concern.Larz wrote: ↑Mon Apr 22, 2019 8:35 amSorry to drag this post a bit askew, but I've read that an oil catch can isn't really needed on newer cars unless they have a GDI engine. Supposedly, there is little chance of carbon build up in our engines because the injectors spray gasoline directly into the valves and the engine burns it, keeping the valves relatively clean. My car has little to no oil loss between changes so I'm thinking I don't need a catch can. I just make sure I get a new PCV valve every two years (20k miles). Am I correct or should I still consider adding a catch can?
I am not sure how often the PCV needs to be changed. I don't think I saw it in my maintenance schedule. However, since the PCV is responsible for removing blow by (exhaust gases, , moisture, emissions, oil, etc that is not burned in engine combustion), and it sends it back into the chamber to be burned. If it gets clogged, it can cause an increase in pressure in the crankcase which can harm seals and gaskets. The most popular lifespan I have seen is 50k miles. So, being anal, I get mine changed every 20-30k miles. The best part is ... they are very inexpensive! It's always recommended to use ONLY OEM replacements - no parts store brands. The dealer charges me about $35 but I buy mine at Infinitipartsonline for less than $20 and take it to the dealer with my own oil when it's time to change it. Here are some videos about PCVs:
Good question. Technically, the single PCV valve is located on the PASSENGER SIDE valve cover because the VQ engines were designed to let out the pressure via this side. If you take a close look there is no PCV on the right valve cover because very few vapors flow through there. However, some people have installed a second catch can. There is no harm in doing this just more cost to help your engine last longer, which is fine by me.
As designed from the factory, the M37 has 2 PCV valves, while the M35 has 1 PCV valve (as Carguy mentioned before me) and that is for both the VQ35DE and VQ35HR.