Cleaning the camshaft check valve (VVT valve) on a Volvo B5244S4
My Volvo V50 2.4i recently threw a couple of VVT related error codes: ECM-640A and ECM-640F and one of the suggestions in VIDA is to clean or replace the inlet camshaft check valve (VVT valve). However, I could not find any instructions online.
I eventually found some procedures in VIDA.
To get access to the valve you will need to remove the plastic inlet manifold and top timing belt cover. The valve is located near the oil fill tube and is held on by one Torx T30 screw.
You can then lever up the valve with a screwdriver. Do not rotate the valve.
Note that there is an o-ring.
Installation is the reverse, torque for the screw is 7 Nm.
Following is the cleaning procedure from VIDA:
Blow compressed air into the oil feed hole (4). Air should come out through both A ports (1 and 3).
Blow compressed air into the oil drain hole (5). Air should come out through the B port (2).
For further function checks continue with "Check function". If the duct seems to be blocked, go to "cleaning".
Connect current to the solenoid. The solenoid should click. It may be easier to hear the click by holding the solenoid.
Blow compressed air into the oil feed hole (4). Air should come out through the B port (2).
If the piston sticks or the solenoid does not work electrically, the direction of flow will not change.
If the duct seems to be blocked, go to "cleaning".
Use: Cleaner, 1161826, (1161828 US)
Allow the cleaner to act for 5 minutes.
Blow compressed air into all holes from both directions and look for contamination. Carry this out with current on and off to ensure that no dirt remains in the ducts.
Use: Cleaning agent, 1161721
Rinse with cleaner, part no. 1161721.
Regrease the solenoid with engine oil to prevent sticking.
After cleaning, check the function by carrying out steps 1 and 2 again.
If the solenoid still malfunctions after cleaning twice, replace the solenoid.
To install, reverse the removal procedure.
Erase DTCs and test drive the vehicle.
Check that no new DTCs have been stored.