My 2000 tj magna is leaking a lot of oil from the filler cap. I replaced the filler cap with another one but its still leaking, could it be the pcv valve? Also when I open the filler cap after running the engine it seems to give out some smoke from inside the rocker cover.

My 2000 tj magna is leaking a lot of oil from the filler cap. I replaced the filler cap with another one but its still leaking, could it be the pcv valve? Also when I open the filler cap after running the engine it seems to give out some smoke from inside the rocker cover.

I suppose the obvious one is to look and make sure hoses are not twisted or blocked, chech both rocket breather hoses, and the one for crank case...

Always can get new cap to make sure its not faulty.

Burnt oil has a habit of carbonising up and blocking the hoses. Some PCV valves can be cleaned out so check everything first. I found the metal tubes in the valve cover where the rubber hoses fit were just about blocked when I last replaced the valve cover gaskets. Some smoke/vapor is often visible if the oil cap is removed. However, if it is a lot of oil coming out it could be piston rings. Need to do a compression test.

if you suspect its the PCV valve then don't worry about cleaning it out, just buy a new one. I got caught out this way myself, spent $12 on a can of cleaner to clean the PCV just to have it fall apart, then went to buy a new one, and it was only $14. Hine sight can be a wonderful thing