Crankcase breather gauze

I’m thinking of fitting the later gauze screen behind the breather housing on the front of my XK120’s cylinder head in an effort to reduce the drips on the floor from the alloy breather tube. I don’t want to fit a catch tank if I can help it. I’m interested to know if the gauze type is more effective than the simple plate baffle with two holes. The later XJ6 type looks a bit more complicated, with two sections of gauze, but it seems like it would fit OK. Is there a correct way up for the XJ type? By the way, the engine is freshly rebuilt and has less than 1000 miles on it. It dripped a lot worse before!


While I do have a catch can into which my breather tube is routed I only notice anything in it when I run the car in colder weather and then, obviously, it is more oily water rather than oil itself. As such I find it strange that your engine would be emitting that much oil. Do you have the baffle installed correctly, as I believe the illustration in the workshop manual is incorrect?


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Chris, I haven’t checked the baffle’s positioning. I believe the holes should be at 12 o’clock and 6 o’clock?


That is correct, I believe (without running out to the garage to check) the manual shows it aligned in a 9 o’clock and 3 o’clock position. If put in that position oil can build up and possibly flow out into the breather pipe.


I don’t think it matters but it is likely left over from the previous design. The E types use a different breather which has two separate chambers (look at one) to see what for, a small hose to somewhere and the large one. The XJ just has one large breather and the orientation shouldn’t matter. The XJs have some sort of steel wool filter as well; I always thought the gauze was supposed to be a flame trap as well as for catching droplets…

On a MK1 diagram they have it at 12 o’clock and 6 , and call it a Baffle
Later MK2 cars have the gauze and call it a filter !
Guess you have 2 ways to deal with it , turn it around to 12-6 o’clock or fit the later gauze type , pic is that of a XJ6 type !


Yes, the XK120 Manual is a drafting error, shows it wrong, at 3 o’clock and 9 o’clock.

6 o’clock and 12 o’clock per the Mark 1 manual is correct.
The amount of drip I get from mine is minimal.

Thanks, guys, this is helpful. I think I’m going to try the XJ6 type gauze. Does anyone know which way up and which way round it goes?

Don’t think it makes any diffrence what way up it goes , but for looks small bit at the top I guess , the Gauze for the MK2 is just one bit .
I may be wrong , but think I read that Jaguar added the Gauze as a fire wall , so flames from the carbs could not get into the engine :thinking:

There seems to be two compartments inside the XJ6 breather housing corresponding to the two sections of gauze in the screen. I’m not sure of the purpose of this arrangement, nor which way up it goes, or which war round the gauze should face.

I am 99% sure all the breather housings are the same size , so you could use the xj6 gauze , with your housing , have marked the top !

These are not pictures of my housing, but an XJ6. One diagram I found for the XJ arrangement shows the smaller section of screen to the top. I think the protruding bit of the XJ gauze might foul the pipe on the inside of my housing, so it may well be that I have to fit it with the protrusion facing away from the housing, towards the cylinder head.