Valve Adjustment DOHC 2.5 Liter Engine:
Both right side resin camshaft sprockets have a single arrow embossed on their front surfaces. The position of these arrows determines which valves are to be measured and/or adjusted. To begin the procedure, turn the crankshaft pulley clockwise until the camshaft sprocket arrows are pointing to the position shown in the figure below (approximately 2 o’clock position). In this position, the #1 intake valve and #3 exhaust valve clearances can be inspected and the clearance adjusted as necessary.
Insert a thickness gauge between the heel of the camshaft and the adjusting shim. Keep the thickness gauge as close to parallel with the shim surface as possible. The exhaust valve clearances are more easily measured while working from beneath the vehicle.
The valve clearance specifications for these engines are:
• Intake valves 0.20 mm ± 0.02 mm.
• Exhaust valves 0.25 mm ± 0.02 mm.
An assortment of 60 shims is available, in 0.01 mm increments, so it’s theoretically possible to get each valve adjusted to exactly its clearance specification. But if the valve adjustment is within 0.02 mm of the specification, do not remove the shim. Changing a single shim size will only bring it 0.01 mm closer to perfection. Moving up (or down) two sizes may cause you to overshoot the specification on the other side.
If the clearance for any of the first set of valves is more than 0.02 mm beyond the specification, write down the actual clearance. You’ll need the information later to determine which shim to install to bring the clearance into specification.
