Hello everyone!
just made here account because this website helped me a lot but I can't find anyone with similar problem as me. So the thing is that I bought my e60 with a badly damaged engine,it's after a complete overhaul and already drove 4k km,but the problem is,it started leaking oil, 1 liter every 500km,the oil I'm using is castrol magnatec 5w40,the valve cover has been replaced and the OFHG and oil radiator gasket also,it helped a bit but when we took of the hose coming from the CCV on the valve cover and looked inside there's still a little bit of oil so we figured that something is still broken. there's no visible leaks either from the oil pan or valve cover or even the head which was also renovated and we still experience huge oil losses(1 green bar on the idrive after 150-200km). Did anyone had similar problems with their n53 or perhaps n52? what should we look into also? maybe wrong type of oil?

 

the N53 normally taskes 5w30, what exactly is the " overhaul" ? a complete rebuild or something else? did you use all new parts.
if an engine is losing 1L of oil every 500km then it should either be leaking massively somewhere or it is burning through a lot of oil.
for burning oil the usual suspect are:
- PCV/CCV system
- Valve stem seals
- piston rings
- maybe EGR system?

 

our mechanic told us that 5w30 might be not that great for that engine because of the engine's operating temperature but we might give it a shot in the next oil change,and yes the overhaul meant complete rebuild,the only parts that stayed and haven't been changed are pistons,spark plugs and ignition coils,the valve stem seals were replaced and also the piston rings,we haven't check the EGR system though because we've figured out only a few days ago that it has one which was suprising for us to see it in a gasoline engine,we also looked under the engine and saw a little bit of oil on a pipe coming from the exhaust right under the engine to somewhere unknown to us which we suspect to be a part of the EGR system. But what's most concerning for us is the oil in the pipe coming form CCV in the valve cover even though it's a fresh new one.

 

quick update here if anyone was or maybe has similar issue with their n53b25,so the reason for the oil was the valve seals,the mechanic bought original corteco seals for the exhaust valves which were good but for the intake Victory Reinz which failed about 1000km since the replacement so what i do recommend is buying original corteco valve seals because such a simple problem can cause so many other problems,also the oil near the pipes going from EGR valve is probably oil being sucked through EGR valve from the exhaust because of the huge oil leak caused by the valve seals,or it dripped from the valves into the intake mainfold and back to the EGR valve which is under the intake mainfold,right now what that oil leak caused for me is 2 dirty catalytic converters and 2 damaged lambda sensors,new set of spark plugs and about 500USD for 1L bottle of oil each 500km i drove.

 

do you know what the oil consumption is now, after all the work? i am at 1L in 4k but im guessing either my valve stem seals are gone (after 300k maybe time) or my PCV is busted since i see (a lot of) oil in my intake manifold. i did try to fix it with an new membrane and it should seal perfectly but im not sure.

 

right now the oil consumption that i have is 0.2l(1 bar on the idrive) every 1800km so 1L every 9000,or as it should be because it's now stuck on 3 bars on idrive since the valve stem seals change and i already drove 5,6k+ km so maybe the seals somehow sealed themself even more? hard to explain but anyways,the oil consumption right now is not noticeable at all for me now,using magnatec 5w40 oil and changing every 15k km,as for the PCV i do not recommend replacing the membrane on your own,i did that and it was a waste of money,buy a febi valve cover,they are using a genuine valve cover but with polished off bmw logo and number,valve stem seals might be gone because mine had 220k km and were gone so that's why they were replaced with the original corteco ones,also you might consider also piston rings replacement if it was never done to that engine