Engine
Engine Oil System
The oil system lubricates, cleans and cools the engine under pressure.
Free guide
Advertisement
Combustion flow
Interactive — tap a partTap a part to see how it fits in the system.
What it does
- Pump circulates oil through galleries
- Filter removes particles
- Oil cools bearings and pistons
- Pressure protects wear surfaces
When it fails
- Oil pressure warning light
- Engine noise on cold start
- Oil consumption
- Oil leak
How to diagnose
- Check the level on a level surface
- Measure oil pressure with a gauge
- Look for leaks at the pan, filter and seals
- Check the oil color and smell
Maintenance
- Change oil and filter on schedule
- Use the correct viscosity and spec
- Top up between changes
- Fix leaks before low-pressure damage
Use the diagnosis order. When a part fails, confirm each hypothesis with measurements before replacing anything — codes and symptoms overlap.