DIAGNOSIS AND TESTING - PCV VALVE - 3.7L
V-6/ 4.7L V-8
(1) Disconnect PCV line/hose (Fig. 19) by discon-
necting rubber connecting hose at PCV valve fitting.
(2) Remove PCV valve at oil filler tube by rotating
PCV valve downward until locating tabs have been
freed at cam lock (Fig. 19). After tabs have cleared,
pull valve straight out from filler tube.To prevent
damage to PCV valve locating tabs, valve must
be pointed downward for removal. Do not force
valve from oil filler tube.
(3) After valve is removed, check condition of valve
o-ring (Fig. 19). Also, PCV valve should rattle when
shaken.
(4) Reconnect PCV valve to its connecting line/
hose.
(5) Start engine and bring to idle speed.
(6) If valve is not plugged, a hissing noise will be
heard as air passes through valve. Also, a strong vac-
uum should be felt with a finger placed at valve
inlet.
(7) If vacuum is not felt at valve inlet, check line/
hose for kinks or for obstruction. If necessary, clean
out intake manifold fitting at rear of manifold. Do
this by turning a 1/4 inch drill (by hand) through the
fitting to dislodge any solid particles. Blow out the
fitting with shop air. If necessary, use a smaller drill
to avoid removing any metal from the fitting.
(8)Do not attempt to clean the old PCV valve.
(9) Return PCV valve back to oil filler tube by
placing valve locating tabs (Fig. 19) into cam lock.
Press PCV valve in and rotate valve upward. A slight
click will be felt when tabs have engaged cam lock.
Valve should be pointed towards rear of vehicle.
(10) Connect PCV line/hose and connecting rubber
hose to PCV valve.
(11) Disconnect rubber hose from fresh air fitting
at air cleaner resonator box. Start engine and bring
to idle speed. Hold a piece of stiff paper (such as a
parts tag) loosely over the opening of the discon-
nected rubber hose.
(12) The paper should be drawn against the hose
opening with noticeable force. This will be after
allowing approximately one minute for crankcase
pressure to reduce.
(13) If vacuum is not present, disconnect each PCV
system hose at top of each crankcase breather (Fig.
20). Check for obstructions or restrictions.
(14) If vacuum is still not present, remove each
PCV system crankcase breather (Fig. 20) from each
cylinder head. Check for obstructions or restrictions.
If plugged, replace breather. Tighten breather to 12
N´m (106 in. lbs.) torque. Do not attempt to clean
breather.(15) If vacuum is still not present, disconnect each
PCV system hose at each fitting, and at each check
valve (Fig. 21). Check for obstructions or restrictions.
Fig. 19 PCV VALVE - 3.7L V-6 / 4.7L V-8
1 - O-RING
2 - LOCATING TABS
3 - CAM LOCK
4 - OIL FILLER TUBE
5 - PCV LINE/HOSE
6 - P C V VA LV E
Fig. 20 CRANKCASE BREATHERS (2) - 3.7L V-6 /
4.7L V-8
1 - CRANKCASE BREATHERS (2)
2 - REAR OF ENGINE
25 - 20 EVAPORATIVE EMISSIONSDR
PCV VALVE (Continued)
