You can use any N54 oilfilter housing gaskets DIY that is out there.
Multiple videos on youtube. FCP EURO guides are good.
Z4 its a bit easier to do than on a 3 series, because theres more room.
To make more room you have to remove the radiator fan. Slides out from top.
You probably need new bolts, and 2 gaskets. New coolant aswell.
Got mine done about 2 years ago, so i dont remember everything.
If its already been leaking down the front of the engine, then its recommended to replace the aux belt aswell.. Oil damages it and it can break. And if it breaks its possible that it gets sucked into the engine by the crank pulley and then it makes a lot of damage that you definately dont want. It gets chewed up by the timing chain and bits of it end up in your oil pan. If you search for it you will find some horror stories out there. There are videos on youtube aswell.
https://www.autoscopecarcare.com/bmw...inside-engine/
There are aftermarket protector plates that you can install behind the crank pulley to prevent aux belt to be sucked into the engine. So if you want peace of mind then buy and install one.
I replaced my belt and belt tensioner for that reason. Pulleys seemed fine so i did not touch those but you can replace them aswell if you wish.
Also when working on the housing be very careful to not get any debris however small into the oil channels.
It did happen to me. After repair on first startup car started to idle ruff. Like a big old american v8 with cams.
So after googling we found out that debris flows with the oil to vanos solenoids, block them etc and they cant actuate properly. Common mishap while doing those gaskets.
So the shop that did the work took out vanos solenoids and small filters that are before vanos solenoids and cleaned them. After that car ran fine again. That was one day of extra free work for them as it was their fault.
i have replaced many gaskets on my engine. Oil filter housing gaskets was the first to go, next did new valve cover with new gasket and recently changed out crankshaft main seals both front and rear. Going to do oilpan gasket aswell in the future. Thats the only one i havent replaced yet of all the common leak spots.
And the the small chain tensioner gasket ring leaked a bit aswell long time ago so replaced that tensioner aswell.