1997 Chevy Tahoe engine noise

Hi there,

You engine is fitted with hydraulic valve lifters one is faulty and is bleeding down, the tick is excessive valve clearance, while the lifter pumps up with oil when the engine is running, you will need to get it replaced, it is good practice to replace all the lifters if one is faulty, you can try doing an engine flush and changing the oil as this sometimes flushes out any carbon build up that may be fouling the lifter valving.

Mark (mhpautos)