Hello to all,
I removed the breather housing (on my 1957 3.4 XK150) to clean it all out inside for the first time in my short ownership. There was a fair amount of liquid "gungy" oil collected between the housing and the baffle plate, but I have no idea how long it took to form there. I will check it out again in a few thousand miles.

The baffle plate was mounted with the two large holes in the horizontal position. My Jaguar technical diagrams show it mounted in both horizontal and vertical positions, yet the service manual says NOT (in bold type in the Jaguar manual) to mount the holes in the horizontal position. I will therefore reassemble it all with the two large holes in the vertical position, but my question is "what possible difference does it make"? Any ideas please?

Also I had (wrongly as it turned out) been expecting to find a gauze screen in there, rather than a baffle plate. It looks to me as if sometime post XK150 Jaguar changed from using a baffle plate to using a gauze screen, and that the production cost of the gauze screen must surely have been higher. My further questions are therefore (1) why did they do that? and (2) would I benefit from swapping my baffle plate for the gauze screen?

Thanks to all for your help,
Tony

 

Some have both, baffle and screen, but mostly later models had the screen. Since this is a crankcase vent ( like the modern PVC ) and by-pass of oil from pistons and timing chains will get to the vent. Not an unusual situation as the engine gets older. I just did a 3.4L with a lot of oil in the breathe and hose was saturated due to smooth cylinder walls with no hone marks left. The vent is a maintenance item to be cleaned at intervals.