This guide will help you replace the PCV Valve or Positive Crankcase Ventilation Valve in a VR V6 Commodore (March 1994 model)
For this guide to work you must first remove the Alternator as described below, this will get you better access to the big nut that
holds the PCV valve in, using a socket on the nut has for me and will for you, burr the nut, so use a nice conforming Open ended spanner instead.
Tools and Parts:
a) 17mm open-ended Spanner for PCV top nut.
b) New PCV Valve (Generally around $10 - 15$)
c) O-ring to suit PCV Valve, and to suit high temperature/oil and fuel contact (In my case there was no O-ring on the original or replacement PCV Valve so I sourced one).
d) A large breaker bar with a 18mm Socket for the Serpentine Belt Tensioner, for removing the belt.
e) A 12mm open-ended spanner for the nut on the main through bolt on the alternator (ignore if yours has stock mounted rear nut to head brace bar).
f) A 12mm socket and extension rod for the small Alternator bolt.
g) A 13mm socket (need verification) for head of the main through bolt on the Alternator.
h) A suitable spanner etc for undoing the +Positive wire on the Battery.
i) A suitable spanner etc for undoing the +B/Positive wire on the Alternator (In my case a 13mm Open-ended spanner)
J) A Pair of long nose pliers.
k) Paper towel/Rags for wiping the O-ring seat clean
Step 1) Using a suitable tool for the +Positive battery terminal, remove the Battery terminal and set aside so it can't come back in contact with Battery +Positive, also remove the Battery negative.
Step 2) Remove the nut (Counter-clockwise) on the back of the Alternator for B+ (Positive output from Alternator down to battery).
Step 3) Remove the excitation plug (two way) connector from the top of the alternator by pressing in the metal clip - The alternator is now electrically separated from the car.
Step 4) Using the breaker bar and the 18mm socket, place it on the serpentine idle wheel bolt, start with the handle pointing straight up,
then come down at a (Counter-clockwise) 90° angle to the left, allow the belt to fall off the water pump pulley, remove the belt, and gently allow the tension to come back to normal rest. Place the belt somewhere where it won't get oil on it etc.
Step 5) Using the 12mm Socket on an extension bar, remove the 12mm headed small bolt (Counter-clockwise) on the alternator bracket closest to the radiator/thermostat housing.
Step 6) Using the 13mm Socket on the front and the 12mm Open-ended spanner on the back (If applicable) remove the main long bolt from the Alternator bracket (Counter-clockwise and closest to the Coil Packs)
Note: in my situation the rear mount for the 12mm nut is missing.
Step 7) Remove the Alternator from the Engine and place somewhere safe.
Step 8) Using the 17mm spanner remove the big nut that holds the PCV valve in.
You may need a soft hit from a hammer to crack it :
Step 10) Using a pair of pliers, gently remove the spring, the spring should have enough grip that the Old PCV valve and O-ring come out in one unit,
as you can see mine was absolutely stuffed and blocked (and hadn't been replaced post rebuild of the motor):
Step 11) Clean up the spring as much as possible and slide onto the new PCV Valve,
Check at this stage that the new valve is the same as the old, and that it rattles and rests easy:
Step 12) Place the new O-ring on the seat side of the new PCV Valve as per this diagram:
Step 13) Before installing the new PCV assembly get paper towel or better a rag
Clean the O-ring seat down inside the Plenum, the entire surface must be bump and dirt free.
Be sure not to let debree fall as this can make its way to the sump or the intake runners.
Step 14) Push the new PCV assembly into the port, the O-ring will slip into the seat.
You will have the spring sitting out about flush with the surface as is pictured below:
Step 15 Place the nut back in and start the thread, only use the 17mm open-ended spanner.
Hand tighten it/make the nut firm but not over tightened, this will make it easier in future to check the operation/replacement again:
Step 16) Re-install the Alternator by following Step 7 back to Step 5 -
Note: tighten all bolts to specific Torque ratings as per a maintenance manual if applicable.
Step 17 Putting the Serpentine Belt back on can be tricky,
This time still follow Step 4 but with a difference,
First get the belt on generally around the Power Steering, Water Pump, Idle Pulley, Air Con Pump and the Harmonic Balancer first,
Then rotate the Tensioner again (Counter-clockwise/90° to the Left)
Carefully slide the belt onto the Alternator Pully, and before allowing tension back on the belt,
check that it is in the Air Con, Balancer and Power steering pulleys correctly,
release tension slowly and feel for correct seating.
Step 18) Follow Step 3 back to Step 2 with attaching the Battery connections in Step 1 being the Last mechanical/electrical step.
Step 19) Start the car to make sure the belt is running ok, and check for Air leaks/oil leaks around the Nut.
Complete and take it for a spin.
Guide completed by Linkwitz
For this guide to work you must first remove the Alternator as described below, this will get you better access to the big nut that
holds the PCV valve in, using a socket on the nut has for me and will for you, burr the nut, so use a nice conforming Open ended spanner instead.
Tools and Parts:
a) 17mm open-ended Spanner for PCV top nut.
b) New PCV Valve (Generally around $10 - 15$)
c) O-ring to suit PCV Valve, and to suit high temperature/oil and fuel contact (In my case there was no O-ring on the original or replacement PCV Valve so I sourced one).
d) A large breaker bar with a 18mm Socket for the Serpentine Belt Tensioner, for removing the belt.
e) A 12mm open-ended spanner for the nut on the main through bolt on the alternator (ignore if yours has stock mounted rear nut to head brace bar).
f) A 12mm socket and extension rod for the small Alternator bolt.
g) A 13mm socket (need verification) for head of the main through bolt on the Alternator.
h) A suitable spanner etc for undoing the +Positive wire on the Battery.
i) A suitable spanner etc for undoing the +B/Positive wire on the Alternator (In my case a 13mm Open-ended spanner)
J) A Pair of long nose pliers.
k) Paper towel/Rags for wiping the O-ring seat clean
Step 1) Using a suitable tool for the +Positive battery terminal, remove the Battery terminal and set aside so it can't come back in contact with Battery +Positive, also remove the Battery negative.
Step 2) Remove the nut (Counter-clockwise) on the back of the Alternator for B+ (Positive output from Alternator down to battery).
Step 3) Remove the excitation plug (two way) connector from the top of the alternator by pressing in the metal clip - The alternator is now electrically separated from the car.
Step 4) Using the breaker bar and the 18mm socket, place it on the serpentine idle wheel bolt, start with the handle pointing straight up,
then come down at a (Counter-clockwise) 90° angle to the left, allow the belt to fall off the water pump pulley, remove the belt, and gently allow the tension to come back to normal rest. Place the belt somewhere where it won't get oil on it etc.
Step 5) Using the 12mm Socket on an extension bar, remove the 12mm headed small bolt (Counter-clockwise) on the alternator bracket closest to the radiator/thermostat housing.
Step 6) Using the 13mm Socket on the front and the 12mm Open-ended spanner on the back (If applicable) remove the main long bolt from the Alternator bracket (Counter-clockwise and closest to the Coil Packs)
Note: in my situation the rear mount for the 12mm nut is missing.
Step 7) Remove the Alternator from the Engine and place somewhere safe.
Step 8) Using the 17mm spanner remove the big nut that holds the PCV valve in.
You may need a soft hit from a hammer to crack it :
Step 10) Using a pair of pliers, gently remove the spring, the spring should have enough grip that the Old PCV valve and O-ring come out in one unit,
as you can see mine was absolutely stuffed and blocked (and hadn't been replaced post rebuild of the motor):
Step 11) Clean up the spring as much as possible and slide onto the new PCV Valve,
Check at this stage that the new valve is the same as the old, and that it rattles and rests easy:
Step 12) Place the new O-ring on the seat side of the new PCV Valve as per this diagram:
Step 13) Before installing the new PCV assembly get paper towel or better a rag
Clean the O-ring seat down inside the Plenum, the entire surface must be bump and dirt free.
Be sure not to let debree fall as this can make its way to the sump or the intake runners.
Step 14) Push the new PCV assembly into the port, the O-ring will slip into the seat.
You will have the spring sitting out about flush with the surface as is pictured below:
Step 15 Place the nut back in and start the thread, only use the 17mm open-ended spanner.
Hand tighten it/make the nut firm but not over tightened, this will make it easier in future to check the operation/replacement again:
Step 16) Re-install the Alternator by following Step 7 back to Step 5 -
Note: tighten all bolts to specific Torque ratings as per a maintenance manual if applicable.
Step 17 Putting the Serpentine Belt back on can be tricky,
This time still follow Step 4 but with a difference,
First get the belt on generally around the Power Steering, Water Pump, Idle Pulley, Air Con Pump and the Harmonic Balancer first,
Then rotate the Tensioner again (Counter-clockwise/90° to the Left)
Carefully slide the belt onto the Alternator Pully, and before allowing tension back on the belt,
check that it is in the Air Con, Balancer and Power steering pulleys correctly,
release tension slowly and feel for correct seating.
Step 18) Follow Step 3 back to Step 2 with attaching the Battery connections in Step 1 being the Last mechanical/electrical step.
Step 19) Start the car to make sure the belt is running ok, and check for Air leaks/oil leaks around the Nut.
Complete and take it for a spin.
Guide completed by Linkwitz