Adjust the hydraulic roller cam valves when the engine is cold for the purpose of getting maximum engine performance and durability. They are typically considered as maintenance-free mainly because they are hydraulic roller cams as opposed to solid lifter camshafts that require periodic valve adjustments. But, if you are doing engine work that involves removing or replacing valvetrain components, they still have to be adjusted correctly in the beginning. It is sometimes better to do it with a cold engine so that the initial position remains consistent despite thermal expansion effects on valve lash settings.
Feeler gauges
- Socket set
- Torque wrench
- Flat-head screwdriver
- Service manual for torque specifications and valve adjustment order
Steps on how to Adjust Valves on Cold Hydraulic Roller Cam:
- Preparation: Disconnect the battery cables and remove any parts which would hinder access to rocker arms and valves such as air cleaner, valve covers among other related ones.
- Rotate Engine: Rotate manually crankshaft bolt clock wise until piston for adjusting cylinder reaches top dead center (TDC) during compression stroke.
- Identify the Valve: Find where TDC is for both your cylinder head’s rocker arm and valve. For V-configuration engines, check out at firing order if you’re not certain about which one will be first in line for adjustment.
- Loosen Lock Nut: Unlock each rocker arm using a proper-sized socket in their lock nuts.
- Initial Adjustment: Keeping nut loose enough, get your adjuster down unto where it touches stem of your valve; this point is commonly called “zero lash.” Zero lash means no pushrod’s up-and-down play with rocker arm starting opening them normally.
- Setting Preload: Tighten adjuster by specified amount given by manufacturer of your engine so as to achieve hydraulic lifter preload since different models may recommend a 1/2 turn to 3/4 turn from zero lash.
- Tighten Lock Nut: While keeping adjuster steady, tighten lock nut up to level of manufacturer’s torque specification since that is normally 15-25 ft.-lbs. Ensure accurate tightening by using torque wrench.
- Check: Use your feeler gauge for checking the clearance existing between rocker arm and valve stem which is set up from hydraulic lifter preload.
- Repeat: Repeat all these steps given above for each valve in accordance with engine firing order.
- Reassemble: Put back any part removed after completing the adjustment of all valves.
- Reconnect Battery and Test: Connect battery and crank engine to check if it makes any ticking or knocking noise. If there is a noise, you will have to re-adjust the valves.
This way, your engine operates at its peak performance and keeps going longer thanks to most efficient operation of hydraulic roller camshaft and valves. Always refer to your vehicle’s service manual when making model specific recommendations or seeking torque specifications.
