Just got an oil change and I hear a rattle coming from the oil cap, when I put my hand on the neck of it I can feel it vibrating. Does this mean I need a new oil pump? My pressure gauge sits just a tad above the middle mark. It's a 04 wj overland v8 ho with 171,000 miles.

Edit : the oil used is a 05/30 weight

 

Anybody

 

Larry I don't think that an oil pump would cause that.. Rattle from the oil cap might mean a pressure issus in the crankcase, usually caused by ring blow by. Some blow by is regular and expected but if it is high I would look at a blocked PVC valve or did you some how "break" the oil cap causing it to rattle. Try a cap from another vehicle and see if it still does it, On old chevys the cap had a gasket that would wear and the cap would rattle a little on high milage vehicles. Hope this helps

 

Where would a blocked PVC valve be at? I haven't touched the oil cap so I know it's not that.

 

PCV valve is in the passenger side valve cover and will problably be hard to get out, the rubber gets hard and usually has to be replaced.. At least that is where it is on my 5.2L 94.

OK now i'm confussed.. You said the oil cap was rattling and when you touched the neck of it you could feel it rattling.. >>>>????? Iwas thinking the oil cap was in the valve cover ! Send pic of what you are talking about.. any old pic should do. I'''ll check in the moring before we go downtown to the NFL expenience for the SUperbowl.. Be gone most of the day after that..

 

The oil cap yrs, but also the the rubber hose you were talking about too.