Some notes and pictures on the removal and cleaning of my 1999 Z3 1.9 camshaft cover with a M43 B19 engine..
The breather tube is fixed onto the camshaft cover pipe by a series of 'barbs' on the pipe and the rubber pipe has similar barb recesses in it. There is a rubber sleeve over the final ~1cm of the rubber pipe which holds it tight.
Some online resources suggest cutting it off and replacing it rather than attempting to remove it !
I initially thought that simply pulling the pipe off would work - it didn't. When you pull the pipe it stretches slightly, reducing its diameter and holding it more tightly! To remove it, I first sprayed the end with silicone spray as a lubricant, then inserted a small screwdriver (with flats that are about the same width as the screwdriver shaft - about 3mm) through the rubber sleeve to loosen it. I then pulled the rubber sleeve away from the end slightly. I then pushed the end of the rubber pipe away from the metal tube, working slowly around the whole of the end.
Remove the camshaft cover bolts and lift it off.
The oil trap 'labyrinth' arrangement inside is simple. There are no valves, springs or oil trap gauze inside. It's just a series of chambers that allow the oil to condense onto the chamber walls. There are three return pipes that allow the oil to drain back into the engine. I soaked the bolts in penetrating oil overnight (they weren't very tightly screwed in), which also ensured that the sealing gasket could be removed without damage. The plate just lifts off once the 10 screws are removed.
after initial cleaning...
The gasket for the cover plate is unusual in that its a single piece, which wraps around the edges of the plate. Part number BMW 11 12-1 739 343. The gasket not only seals the periphery of the cover plate, but also the screw heads. The 'finger' arrangements appear to lock into place with the gasket underneath via a holes in the plate. Weird!
cleaning
I cleaned mine with petrol and a tooth brush. This removed a lot of the black oil deposits, but left some black baked-on sections. I think normally it would be sufficient to flush with solvent cleaner until it runs clear, without the need to dismantle the labyrinth. I had to resort to using a plastic pan scourer with 'wet and forget' (a slightly alkaline cleaner). Jet washing removed some further stubborn deposits. I finally used solvent cleaner squirted through the three return pipes (there was dirt in them, which the other cleaning methods had failed to shift).
On the picture below, any air flow travels from the bottom, up through the chambers on the left and down the long passage on the right, before exiting through the tube on the bottom right, as shown in the picture below:
The breather tube is fixed onto the camshaft cover pipe by a series of 'barbs' on the pipe and the rubber pipe has similar barb recesses in it. There is a rubber sleeve over the final ~1cm of the rubber pipe which holds it tight.
Some online resources suggest cutting it off and replacing it rather than attempting to remove it !
I initially thought that simply pulling the pipe off would work - it didn't. When you pull the pipe it stretches slightly, reducing its diameter and holding it more tightly! To remove it, I first sprayed the end with silicone spray as a lubricant, then inserted a small screwdriver (with flats that are about the same width as the screwdriver shaft - about 3mm) through the rubber sleeve to loosen it. I then pulled the rubber sleeve away from the end slightly. I then pushed the end of the rubber pipe away from the metal tube, working slowly around the whole of the end.
Remove the camshaft cover bolts and lift it off.
The oil trap 'labyrinth' arrangement inside is simple. There are no valves, springs or oil trap gauze inside. It's just a series of chambers that allow the oil to condense onto the chamber walls. There are three return pipes that allow the oil to drain back into the engine. I soaked the bolts in penetrating oil overnight (they weren't very tightly screwed in), which also ensured that the sealing gasket could be removed without damage. The plate just lifts off once the 10 screws are removed.
after initial cleaning...
The gasket for the cover plate is unusual in that its a single piece, which wraps around the edges of the plate. Part number BMW 11 12-1 739 343. The gasket not only seals the periphery of the cover plate, but also the screw heads. The 'finger' arrangements appear to lock into place with the gasket underneath via a holes in the plate. Weird!
cleaning
I cleaned mine with petrol and a tooth brush. This removed a lot of the black oil deposits, but left some black baked-on sections. I think normally it would be sufficient to flush with solvent cleaner until it runs clear, without the need to dismantle the labyrinth. I had to resort to using a plastic pan scourer with 'wet and forget' (a slightly alkaline cleaner). Jet washing removed some further stubborn deposits. I finally used solvent cleaner squirted through the three return pipes (there was dirt in them, which the other cleaning methods had failed to shift).
On the picture below, any air flow travels from the bottom, up through the chambers on the left and down the long passage on the right, before exiting through the tube on the bottom right, as shown in the picture below:
