DRIVERS ASK, TOM ANSWERS: ENGINE

PROBLEMS SOLVED

Tom,

Q I have a 1992 Ford Bronco full-size with 116,000 miles. It has a 5.0-liter

302 engine. My problem? Oil is getting into the air filter. Can you tell me if
this is blowby or a PCV problem? I checked the EGR valve and found that
there’s a lot of carbon buildup in the intake manifold. Why do you think this
is happening? Thanks for your input.

Joe—Buffalo,    New York

Joe,

A Beneath the grommet (that the PCV valve pushes into) on the back of the

intake manifold is a pellet-style mesh vapor filter. This filter has a tendency
to plug solid with sludge. Once plugged, the crankcase does not properly
ventilate. The resulting pressure forces the oil-laden engine vapors backward
through the air cleaner hose and fills the air cleaner housing with oil.
Replacement of the filter screen beneath the PCV valve will take care of this
problem in the majority of cases.

Good    luck.