Neptune idle crankcase ring

Crankcase noise when Neptune is idling may be caused by the following reasons:

1. Wear of crankshaft bearing: If the crankshaft bearing is worn or damaged, noise will be generated during idling. Crankshaft bearing is the key component to support the rotation of crankshaft. If damaged, noise may be generated.

2. Improper adjustment of valve clearance: When the car is idling, the frequency of valve closing and opening will increase. Too large or too small valve clearance will cause noise when the valve is idling.

3. Wear of the valve spring: The function of the valve spring is to make the valve rebound and keep it in normal working condition. If the valve spring is worn, noise may be generated at idle speed.

To sum up, the crankcase noise of Neptune at idle speed may be caused by the wear of crankshaft bearing, improper adjustment of valve clearance or wear of valve spring. In order to diagnose the problem accurately, it is recommended that you send the vehicle to a professional garage for further inspection and maintenance.