The hydraulic lifters are installed into a machined bore in the cylinder head and receive their lubrication via a series of oil galleys machined into to the engine block and cylinder head. The engine oil is supplied under pressure by the engine's oil pump.
If removed the observe the following guidelines:
If a valve has contacted a piston, the lifter associated with that valve should be checked for an out of round condition. If the lifter is dished or out of round by more than 0.002 inches (0.05mm), or if the lifter binds in the bore of the cylinder head, it should be replaced.
To inspect a hydraulic lifter for excessive noise proceed as follows:
- Start the engine and allow the engine to run until the coolant temperature reaches 176°F (80°C).
- Raise the engine speed to 2,500 RPM for 2 minutes, and if necessary test drive the vehicle.
- If the valve noises disappears but then reoccurs during the test drive, on 1.8L and 2.8L V6 models, the oil retaining valve should be replaced.
The oil retaining valve is located as follows:
- If the valve lifter(s) is/are still noisy proceed as follows:
- Remove the cam cover(s).
- Position the valve such that the pointed end is facing upward.
- Using a soft wooded or plastic wedge, press down on the lifter.
- On 1.8L and 2.8L V6 models if a 0.008 inch (0.20mm) feeler gauge can be inserted between the camshaft lobe and lifter, the valve lifter should be replaced.
- On 2.0L and 2.8L VR6 models, if a 0.004 inch (0.10mm) feeler gauge can be inserted between the camshaft lobe and lifter, the valve lifter should be replaced.
- Remove the camshaft(s) to replace the hydraulic lifter(s).