If you're experiencing valve train noise (often mistaken for needing tappet adjustment), the problem is likely one of the following:
* Low oil pressure: Check your oil pressure. Low pressure means the lifters aren't being properly filled with oil. This needs immediate attention.
* Worn lifters: Hydraulic lifters can wear out and fail to self-adjust properly. This requires lifter replacement.
* Worn camshaft lobes: A worn camshaft will also contribute to noisy valve train. This requires camshaft replacement or rebuilding.
* Incorrect valve train components: Using the wrong pushrods or rocker arms can cause noise.
* Dirty or low-quality oil: Thick or contaminated oil can restrict oil flow to the lifters. Use the correct weight oil specified for your engine.
Instead of trying to adjust them, focus on diagnosing the root cause of the noise. Start by checking your oil pressure and then consider the other possibilities listed above. If you're unsure, consult a qualified mechanic.
