P0298: Engine Oil Over Temperature

What it means

The control module detected engine oil temperature above its calibrated limit. The code does not by itself establish oil breakdown or bearing damage.

At a glance

• Usually lights the check-engine light
• The engine or gearbox may go into limp mode

How it works

The control module monitors engine oil temperature through an oil-temperature sensor or related data. P0298 sets when the reported oil temperature exceeds the calibrated limit; it does not by itself confirm that the oil has deteriorated or engine bearings are damaged.

Common causes

Most likely first.

1. Low engine oil level
2. Cooling or oil temperature control problem
3. Oil temperature sensor or circuit fault

Symptoms

• Engine-temperature or oil-temperature warning light, if equipped
• Overheating warning or message
• Reduced engine power, if protection mode activates

How to diagnose it

1. Check the oil-temperature freeze-frame data and warning messages, and look for companion engine-cooling or sensor codes.
2. When the engine is cool and parked level, check the oil level and look for obvious leaks; do not open a hot pressurized cooling system.
3. Compare scan-tool oil-temperature data with the engine’s other temperature readings from a cold start to spot an implausible sensor reading.
4. Inspect the oil-temperature sensor connector and wiring for damage, poor contact, or contamination.
5. If the temperature reading appears credible, check for cooling-system or oil-temperature-control problems using the manufacturer’s diagnostic procedure.

Common fixes

• Top up the engine oil with the specified grade if the level is low, and repair any leak found.
• Repair damaged or loose oil-temperature sensor wiring or connector.
• Replace a confirmed faulty oil-temperature sensor.
• Repair a verified engine-cooling or oil-temperature-control fault.

Can I keep driving?

If the oil-temperature warning is active, the engine is overheating, or power is reduced, pull over safely and switch off the engine; continued driving can cause serious engine damage. Let it cool and check the oil level before deciding whether it can be moved.