03-01A-3
Engine, 3.8L
03-01A-3
DESCRIPTION AND OPERATION (Continued)
Valve Train
The valve train consists of:
•
hydraulic roller valve tappets (6500) which provide
automatic lash adjustment. While riding on camshaft
lobes, their up-and-down motion is transferred to the
rocker arms (6564) through push rods (6565).
•
six valve tappet guide plates (6K5 12) which are
held in place by a spring steel tappet guide plate
and retainer (6K564) preventing the roller valve
tappets from turning.
•
pedestal-mounted rocker arms pivoting on rocker
arm seats (6A528) which are bolted to the cylinder
heads (6049).
The valves are arranged alternately intake valve
(6507)
I
exhaust valve (6505).
Positive Crankcase Ventilation System
All engines are equipped with a positive closed-type
crankcase ventilation system recycling the crankcase
vapors to the intake manifold (9424).
Engine Lubrication System
/"'""'-
Oil Pump
The engine lubrication system is of the force-feed type
in which oil is supplied from the oil pump (6600) under
full pressure to the following:
•
crankshaft (6303)
•
connecting rod bearings (62 1 1)
•
hydraulic valve tappets (6500)
•
camshaft bearings (626 1)
A controlled volume of oil through the valve tappets is
supplied to:
•
push rods (6565).
•
rocker arms (6564).
All other moving parts are lubricated by gravity flow or
splash.
The rotary gear-type oil pump:
•
develops the oil pressure.
•
is located in the engine front cover (60 1 9).
•
is rotated by the camshaft position sensor housing
shaft through an oil pump intermediate shaft
(6A6 18).
A full-flow oil bypass filter (67 14) is externally
mounted on the oil pump and filter body (6603).
Normally all engine oil passes through the oil bypass
filter element. However, if the oil bypass filter element
should become restricted, a spring-loaded bypass
valve will open which allows an uninterrupted flow of oil
to the engine's moving parts.
Oil Pan
The moulded aluminum oil pan (6675) is bolted to the
bottom of the cylinder blocks (6010).
The oil pan acts as a reservoir holding lubricating oil
that is pumped through the engine by the oil pump after
start-up.
Engine Cooling System
The engine cooling system consists of:
•
radiator (8005).
•
water pump (8501).
•
cooling fan motor (8K62 1) and fan blade (8600)
which are activated by the constant control relay
module (CCRM).
•
radiator coolant recovery reservoir (8A080) which
is located beside the radiator and aids in maintaining
the correct volume of engine coolant mixture in the
cooling system.
The water pump is:
•
of a conventional design.
•
driven by the accessory drive belt (8620).
Drive Belt System
The 3.8L OHV engine is equipped with a serpentine
drive belt (8620). To ensure maximum life, always
replace the drive belt with the same type as originally
installed.
The drive belt system operates as follows:
•
The accessories mounted on the front of the engine
are belt-driven.
•
A serpentine drive belt is routed over each
accessory pulley.
•
The accessory pulleys are driven by the crankshaft
pulley (631 2) which is bolted to the crankshaft
(6303).
For service procedures, including tensioning, refer to
Section 03-05.
1997 Thunderbird, Cougar July 1996