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. |