TM10-3950-672-24-2
Oil Coolers
The engines use full flow, plate type oil coolers (3). The
oil flows through a cast passage in the cooler cover and
through the element where it is cooled by engine coolant
flowing past the plates of the element. The four cylinder
engine uses an element with five plates (A), the six
cylinder uses an element with seven plates (B).
Because of differences in plate restriction and oil pump
capacities, the oil cooler components are not
interchangeable between the four cylinder and six
cylinder engines. The use of incorrect components can
cause high or low oil temperature, varnish and sludge
build up.
Note: Prior to 10/21/86 six cylinder
engines were assembled with 9 plate
oil cooler elements.
Oil Filters
After the oil is cooled, it flows through the full flow oil filter (4). The filter for the six cylinder engine is longer than the
filter for the four cylinder engine.
Caution: Never use a filter for a six-cylinder engine on a four cylinder engine in order to extend
the oil change interval.
Oil Filter Bypass Valve
The oil cooler cover contains a bypass valve (5) that will let the oil flow bypass a plugged filter. The valve is designed to
open when the pressure drop across the filter is more than 138 kPa [20 PSI], as with a plugged filter, and lets the oil
continue on through the engine. When a filter becomes plugged, an oil pressure decrease of 60 kPa [10 PSI] or less
from the normal operating pressure can be observed on the vehicle oil pressure gauge.
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