How to Check the Hydraulic Valve Assemblies on an Engine Block
- 1). Raise and secure the engine hood. Check the oil level and fill if necessary. One cause of valve noise is excessive oil in the crankcase; if the oil level is high, drain some off at the oil-pan plug until the level is correct. Start the engine and let it fully warm up for about 20 minutes. To properly check the valves, the engine must reach normal operating temperature.
- 2). Remove the valve covers which are located above the spark plugs on the engine block. Four-cylinder engines have one valve cover, while "V" engines have two. Remove the valve cover bolts with a socket wrench and socket, lift the valve cover(s) off and place the bolts inside for safe keeping.
- 3). Listen to the valvetrain while the engine is running. Valves produce noise, a clackety-clack sound, while operating. Listen for any unusually loud sounds. These noises are normally heard above normal engine sounds with the valve covers on as well. Try to determine where any strange noises are coming from.
- 4). Turn the engine off and inspect the valvetrain, taking care not to burn yourself on the hot engine. Check for wear marks, scores and loose hold-down nuts on all rocker arms, which are located between the valves and pushrods. Also inspect all pushrod ends for wear and scoring.
- 5). Look for excess varnish, sludge and grit on the entire valve train. Remove a rocker arm nut, located in the center of the rocker arm. Pull out one of the pushrods, and inspect for sludge and varnish. If one is dirty, all are probably dirty. If so, a thorough valvetrain cleaning may be necessary, requiring removal of all pushrods, lifters, valves and rocker arms. When finished inspecting the pushrods, place the rocker arm and nut back on the valvetrain. Tighten the nut just to the point when the pushrod no longer jiggles when grasped, and no tighter..
- 6). Check for bent valves. An easy way to do this without removing the cylinder head is to remove the spark plugs, one at a time, with a socket wrench and spark plug socket. Manually pull off the spark plug wire and remove the plug. Look into the spark plug hole using a small flashlight, checking for damage or scores, on the piston tops. If any are present, the valve likely hit the piston and is probably bent. Replace each spark plug and wire as you go along. Bent valves indicate the need for valve replacement.
- 7). Replace the valve-cover gaskets. Us a gasket scraper to remove any remaining pieces of the old gasket from the cylinder head and valve cover. Place the new gaskets on the cylinder head and re-bolt the valve covers to the engine.