For 1990-2009 cars

The following conditions may produce engine knocks on initial start-up, but only last a few seconds:

• | Improper oil viscosity.

- | Install proper oil viscosity for expected temperatures.

- | Refer to Maintenance and Lubrication.

• | Hydraulic lifter bleed down

- | Clean, test and replace hydraulic lifter, as necessary.

- | When the engine is off, some valves will open. Spring pressure against the lifters will tend to bleed the lifter down. Repair the lifter only if the problem is consistent.

- | Engines operated for only short periods between start-ups may have lifter noise that lasts for a few minutes. This is a normal condition.

• | Excessive crankshaft end clearance; Replace the crankshaft thrust bearing.

• | Excessive front main bearing clearance; Replace the worn parts.

• | Timing chain tensioner malfunction; Clean, inspect and replace the timing chain tensioner, if required.