If a gasoline engine lubricating system is showing low oil pressure, which will NOT be the cause?

If a gasoline engine lubricating system is showing low oil pressure, which will NOT be the cause?

• A. Worn bearings
• B. Faulty oil pump
• C. Low level of urea
• D. Leaking oil pressure sending unit

Answer: (C)

Oil pressure in a gasoline engine is determined by the oil pump’s ability to build pressure and the resistance in the lubrication path. Causes of truly low oil pressure include wear that increases bearing clearances (which makes it easier for oil to escape and pressure to drop), a failing oil pump (can’t generate enough pressure), or a leak or faulty pressure sensor (which can give a low reading or reduce the actual pressure). A low level of urea, however, is unrelated to the lubrication system. Urea is used in exhaust aftertreatment (SCR) and has no role in the engine’s oil circuit, so its level would not affect oil pressure. Therefore, the option describing a low level of urea would not cause low oil pressure.

Oil pressure in a gasoline engine is determined by the oil pump’s ability to build pressure and the resistance in the lubrication path. Causes of truly low oil pressure include wear that increases bearing clearances (which makes it easier for oil to escape and pressure to drop), a failing oil pump (can’t generate enough pressure), or a leak or faulty pressure sensor (which can give a low reading or reduce the actual pressure). A low level of urea, however, is unrelated to the lubrication system. Urea is used in exhaust aftertreatment (SCR) and has no role in the engine’s oil circuit, so its level would not affect oil pressure. Therefore, the option describing a low level of urea would not cause low oil pressure.