Oil filler /breather cap

[kalindi]

I have a BMC 1.5 diesel engine and the oil filler/breather cap states that it should be replaced every 12000 miles or 12 months. I have just bought the boat but by the looks of the cap I am pretty sure that it has never been replaced. My question is does it really need to be renewed and if so does it have to act as a breather. The cover that it is mounted on is already vented with a pipe leading to the air filter as is the vent from the crankcase. If the cap acts as a breather as well then the hot oil vapour is escaping into the engine space and contributing to the engine smells in the cabin. I know that some air is escaping from the cap as when the engine is running at over 1000rpm I can feel the escaping air around the cap. So is it ok just to use a plain cap to fill with oil when required and do away with the breather function. Thanks as allways in anticipation of the advice.

 

[ThereAndBack]

If there is a mesh inside the cap you may want to check/clean it. I have never heard of the cap needing regular changing on a BMC diesel.

No doubt, someone will be along soon with contradictory advice.

Alan

 

[Marsupial]

No Alan you're spot on, clean it dip it in oil and keep but in the back of my mind I do recall that the A and B series BMC engine manual did suggest changing it but I dont remember ever anyone doing it.

DONT replace it with a unvented cap this could cause all sorts of corrosion problems.

 

[kalindi]

Thanks for the comments, I will have another look this weekend and see if it needs cleaning etc.