hey i have a 98 f150 4.2 and it started running really rough and there water getting in the oil. i compression tested it and there is lower compression in one cylinder. would that be the lower intake gasket? or do i have to change the head gaskets? also if it is the intake gasket does anyone know where i could find a "how to" guide. Thanks guys!

 

Most likely your intake. But that low compression.... I would go ahead and do both. Thats what I'd do.

 

The intake gasket issue causes water to get in the cylinders. Water in the oil is something else, and with low compression in a cylinder you need to be prepared for a full teardown.

 

ok thanks. well we pretty much got it narrowed down to the passenger side head gasket. anyone know where i can find some step by step directions?

 

I'd buy a Chilton's or a Haynes.