Hello,

I've been trying to read every thread I can find across multiple sites but I haven't found a solution yet to my vanos problems. So I've been getting intake vanos and boost deactivation recently. Swapped vanos solenoids and code remained on intake. Put different solenoid into intake and it helped for a couple of days but codes came back. Changed the oil and it helped for a couple of days but codes came back.

However I suspect it to be multiple issues because the newer vanos solenoid is adjusting much faster than the old one which was swapped top/bottom previously about a year ago.
I checked the vanos filters yesterday they were clean but the valves seemed very stiff it was difficult to get them to move even by sucking air through them as hard as possible. I've checked the oil filter housing, the cage is in there and seems okay.

Now the weird issue I'm having is that the car is reacting better to the new solenoid so I think the old one was bad anyway. I can cold start the car now with no issues where previously it would misfire and sometimes stall before the vanos would smooth out eventually.

Now I can run the car as much as I want to, doing 3rd 4th 5th 6th gear pulls with no issue, however after the oil gets hot and I turn it off or even let it idle for 5-10min (as happened last night tried not to turn it off to avoid codes) it will immediately throw codes upon restart and pulling away. Last night I cleared and reset adaptations after the codes popped up upon idling and it worked fine the rest of the trip.

Since the vanos filters were clear of any shavings or debris I'm hoping the cam ledges are fine. At this point I'm thinking/hoping the vanos valves are getting stuck when hot ? When we removed the filters there was very little if any oil which points to them being defective and letting oil drain out of the head ? When the car is running it runs fine but when the vanos filters are needed to hold pressure they could be failing to do so ?

Any advice would be great.

Car is 2009 135i with single turbo kit running pump gas tune alone.