E36 328 oil consumption

[Raybimmer]

If you take the coil packs out stick a screwdriver down next to the spark plug before removing the plug . Check if there is oil on the tip of the screwdriver .This indicates the gaskets are leaking .
These rubber gaskets get hard and brittle like plastic and do not seal properly when they are like this .

 

[sclass]

If you take the coil packs out stick a screwdriver down next to the spark plug before removing the plug . Check if there is oil on the tip of the screwdriver .This indicates the gaskets are leaking .
These rubber gaskets get hard and brittle like plastic and do not seal properly when they are like this .

How expensive are valve guides and how many does my motor have? And can I assume 24 valve-stem seals?

On another note, if the valve guides are worn, shouldn’t the engine loose smoothness and/or make some sort of rattling noises (especially at high revs)?

 

[Raybimmer]

Your valve is held against the seat by the valve spring ( single in M52B28 and double in M50B25 ) . When the valve is opened by the cam is happens so quick it will not make a rattling noise .

I know that if the head is off the car and stripped you can insert each valve into its guide and lift it a few mm off the seat and check for sideways play .I don't know what the measurement is off hand . If the valve stem seals are new you should not get oil going down the valve stem side and getting burnt in the cylinder .
Valve stem seals may be cheap , say R50 or R100 or so for 24 but the strip and assemble labour may be R1000 .

You need to go through the comp test and downhill test to see where the problem area is . The tappet gasket likes to leak oil down onto the exhaust manifold , you may smell this at times .
Good luck .