What Does P0298 Mean?
The engine oil temperature has exceeded the maximum safe operating threshold as determined by the ECM. This code indicates the engine oil is overheating, which dramatically reduces its lubricating effectiveness and can lead to accelerated engine wear or failure. The driver may notice a warning light, reduced engine power (limp mode), or hear unusual engine noise. Oil temperature typically should not exceed 250-275 degrees F (120-135 degrees C) under normal operation.
Safety Warning
Stop driving immediately if the oil temperature warning is active. Overheated engine oil loses its lubricating film strength, which can cause bearing failure, piston seizure, or catastrophic engine damage within minutes. Allow the engine to cool completely before investigating.
Common Causes
30%
Insufficient or degraded engine oil that has lost its thermal capacity and viscosity properties
25%
Faulty engine oil cooler that is clogged, leaking, or has restricted coolant flow
20%
Engine oil temperature sensor malfunction providing false high readings
15%
Cooling system issue (low coolant, faulty thermostat, restricted radiator) causing overall engine overheating
10%
Severe driving conditions such as towing, track use, or prolonged high-RPM operation exceeding the oil cooling capacity
Diagnostic Steps
1
Check engine oil level and condition with the engine warm; low oil level or extremely dark/thin oil indicates the root cause. Oil should be at the correct level and not have a burnt smell.
2
Monitor engine oil temperature PID and engine coolant temperature PID simultaneously during a drive cycle; oil temp should track within 20-30 degrees F of coolant temp. A large gap indicates an oil cooling issue.
3
Inspect the oil cooler for external leaks, blockage, or damaged lines; verify coolant is flowing through the oil cooler by feeling both inlet and outlet hoses for temperature.
4
Test the oil temperature sensor by measuring its resistance at a known temperature and comparing to the manufacturer's resistance/temperature chart (e.g., ~2000 ohms at 68 degrees F, ~100 ohms at 230 degrees F).
5
Verify the cooling system is functioning properly: check coolant level, thermostat opening temperature (typically 195-210 degrees F), radiator fan operation, and radiator for blockage.
Estimated Repair Cost
$50 - $800
Parts + labor, varies by vehicle and location
The engine oil temperature has exceeded the maximum safe operating threshold as determined by the ECM. This code indicates the engine oil is overheating, which dramatically reduces its lubricating effectiveness and can lead to accelerated engine wear or failure. The driver may notice a warning light...
The most common cause of P0298 (Engine Oil Over Temperature Condition) is: Insufficient or degraded engine oil that has lost its thermal capacity and viscosity properties
Typical repair costs for P0298 range from $50 to $800, depending on the vehicle, location, and whether you do it yourself or go to a shop.
Stop driving immediately if the oil temperature warning is active. Overheated engine oil loses its lubricating film strength, which can cause bearing failure, piston seizure, or catastrophic engine damage within minutes. Allow the engine to cool completely before investigating.
Start by connecting an OBD2 scanner to read the code and any freeze frame data. Then follow the diagnostic steps specific to P0298 to identify the root cause.
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Quick Info
Category
Powertrain
System
Engine Lubrication System
Difficulty
Type
Generic (SAE)
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