What are the causes of excessive engine oil pressure?
2 Answers
Reasons for excessive oil pressure: First, the oil viscosity is too low; second, the oil strainer mesh or oil filter element is clogged; third, the spring force of the pressure relief valve or return oil valve is weakened or broken, or the valve sealing surface is not tight, causing oil leakage and pressure relief; fourth, the main bearing or connecting rod bearing clearance is too large; fifth, the oil pump is not working properly. Here is additional information: Oil pressure sensor: The oil pressure sensor is usually installed in the main oil passage. If the oil pressure gauge and oil pressure sensor are normal, but the oil pressure gauge indicates that the pressure is too low, the possible causes of the failure can be analyzed based on the composition of the lubrication system and the oil circuit.
I've been driving trucks for long-distance hauls for twenty years, and I've seen quite a few cases of high oil pressure. Mostly, it's because the oil is too viscous—like using a high-viscosity grade in cold weather, which makes the oil flow poorly and causes the pressure to rise. Additionally, the pressure relief valve inside the oil pump often gets stuck or wears out, making it pump too much oil and causing a pressure spike. If the oil filter isn't replaced for a long time and gets clogged, the oil passages get blocked, and the pressure naturally increases. More hidden issues include sludge or debris buildup in the engine's oil passages, blocking the flow. I remember one time the oil pressure gauge showed abnormally high readings, and it turned out the sensor was faulty and giving false readings. Such problems need to be addressed immediately—high oil pressure can damage gaskets and seals, causing leaks, or even harm engine bearings. To avoid this, stick to regular maintenance, check oil levels, use the manufacturer-recommended oil type, and don't delay if you notice anything unusual. Taking it to a repair shop for a professional diagnosis with the right tools is always the right move.
