engine back pressure

[fuzzer66]

2000 ford ranger 2.5L has some back pressure coming out of the oil dip stick tube...the cat. converter doesn't seem to be clogged. any ideas on what else to look at....thanks

 

[4b316]

Check the crankcase vent.How many miles?rings might be getting bad

 

[tomw]

Oil out the dipstick means one of two things: blowby past the piston rings or a messed up PCV system.
Blowby is mostly caused by stuck rings, or rings that lost their tension due to overheating.

The PCV valve can get stuck, and block all flow to the intake, causing a buildup of pressure in the crankcase. The PCV valve is located 'in-line' in the large (3/4"?) hose coming up under the intake manifold, around the front of the intake, and into the bottom of the upper intake. Halfway along, there will be a lump that is the PCV. The replacement may come with a plastic two-tubed insert which you don't need.
tom