lifters have allways mad a slight noise. Now the noise is way above normal. very loud and very wrong. The car has good power. Can the valve cover be removed and the lifters be adjusted?
Chevrolet Q&AAsk Your Question
2005 Chevrolet Malibu Question: lifters are the adjustable
Answer #1patrick mannion from Greg Solow's Engine Room, February 09, 2011, 20:30Master
Your engine has hydraulic valve lifters with no adjustment. Special tool is needed to hold the camshaft during replacement. First check the engine oil level! After that your engine has hydraulic lifters that automatically adjust the intake and exhaust valve clearance using engine oil pressure when the engine is running. Engines with hydraulic lifters need to have oil changes at the recommended intervals to keep the oil clean and fresh and the correct weight or viscosity of engine oil . A small bit of dirt or sludge can "gum" up the lifters and cause the oil not to properly adjust valve clearances. Sometimes this noise goes away after initial start up or after the engine warms up. If it is as simple as "lifter noise" try adding an oil additive called Risolene, it is a low viscosity high detergentcy oil additive that helps clean lifters.