I'm changing the headgasket and am waiting for the replacement. I tried to undo the plastic oil filter cartridge screw on top which seems exceptionally tight. I don't have the proper tool so tried to improvise. Eventually gave up and resorted to large stilsons (used very carefully). The cap finally yielded. I've never known such a tight fitting plastic top!!!!! Has anyone else had problems in undoing this oil filter top cap? I'm now waiting for a replacement cartridge and am fearful of cross threading the cap when I put it back on. Does anyone know if heating the cap will cause it to expand and therefore screw on more easily????