5 Reasons Your Diesel Engine Has a Low Oil Pressure and How to Fix Them

Detecting low oil pressure in your engine can be indicative of a major problem. However, we urge you to not freak out and consider that while it is possible a major fault might have occurred, it is likely that the low oil pressure can be fixed with a simple solution.

In our time as an RV and diesel semi truck repair service, we have seen plenty of such cases. Aided by our experience and expertise, here is a list of 7 reasons why your car may be struggling with low oil pressure in the engine.

#1 Not Enough Oil in the Engine

If your car signals low oil pressure, the first palace you should look at it is the crankcase. Surprisingly (or not so surprisingly) this is one of the most common reasons. If the oil level has gone below the supply tube, the pump will no longer be able to fill up the engine components.

Fix - It is fairly simple to fix this situation; refill the compartment to the correct level of oil. Do consult the operation manual if you are new to it. The manual will also let you know of the most compatible with your engine.

#2 Oil is Contaminated

If the oil becomes contaminated with diesel fuel, coolant, or water it will lead to an increased amount of liquid in the crankcase. This then leads to excess fluid leaking from somewhere in the engine.

Fix - In such situations, a mechanic will take apart the engine to pinpoint the source of the leakage. Once the leak is reinforced, the contaminated oil is to be drained and the compartment refilled with the appropriate grade of oil. You will also want to change your oil filter.

#3 Bypass Valves Are Open

The presence of debris and dirt in the oil can result in the oil bypass valves being set to the open, further leading to low oil pressure in the engine. The debris usually comes from dirt or metal shavings from damaged pistons, shafts, etc.

Fix - Remove the oil bypass valves and clean them free of clogged debris and dirt. Be sure to clean the valve bore as well. Change the oil and filter before putting your shiny, newly cleaned bypass values back into place.

#4 Passages Are Clogged or Disconnected

When the oil passages are clogged or broken, they will inevitably cause low oil pressure in the engine. This, in particular, is a common issue we face with many semi truck repairs. Sometimes, instead of debris or wear, the oil lines are misaligned. When the holes don’t line up next to each other, the normal oil flow is hampered. This may also be resultant of a damaged piston or cooling nozzle.

Fix - You should take your car to a mechanic and have them check that the passages are aligned properly. If any line has tears in it, the mechanic will fix that too.

#5 Broken Oil Pump

Finally, if the supply side of the oil pump has an air leak, it will give rise to cavitation, further resulting in loss of oil pressure. Other times, the oil pump may be compromised because of the extensive wearing of the gears. When the gears are too worked out to create enough suction, the oil pressure will plummet.

Fix - Ask the engine builder to repair or replace the gears, as they see fit. If however, the pump is too worse for wear, it might be time to buy a new oil pump.

Word on the Street

Silverado Road Service Diesel Truck and RV Repair Shop was founded in 2000 by a local Oklahoma family. We run seven days a week to make sure our patrons can always count on our expert quality repair services. From RVs to semi truck repairs, Silverado has made for itself in Oklahoma City. Call us at 405-830-8792 for more information!