oil pressure warning light

Possible Causes of Low oil pressure at idle

In Engine Oil by Josh S2 Comments

oil pressure bearing

Low oil pressure is really bad for any car engine and if the oil pressure gets too low, it can damage your engine with permanent damages within seconds.

But what could cause a low oil pressure and how do we fix it? For how long time can my engine run with low pressure? Could a faulty oil spec cause low pressure on my engine when it’s hot? In this article, the most common questions will be answered.

The most common causes of low oil pressure are low oil level, faulty oil type, damaged oil pump, dirt oil pickup or an internal oil leak inside the engine. A low oil pressure warning light could also be caused by a faulty oil pressure sensor or a faulty instrument cluster/wirings.

ProblemSymptomsCausesSolutions
Low oil pressure at idleNoises from engine

Oil level/pressure light on dashboard

Limp mode

Damaged Engine
Low oil level

Wrong type of oil

Dirty Pickup at oil pump

Damaged Oil pump

Internal oil leak inside engine

Faulty oil pressure sensor

Faulty Instrument cluster
Fill up oil

Replace Engine Oil + Filter

Replace Oil pump

Repair internal oil leak

Replace oil pressure sensor

Replace Instrument cluster

 

What could happen if my oil pressure is too low?

A 4-stroke engine in a car got a very long lifetime, it is mostly because it uses a high pressure on the rotating parts. Instead of having a bearing that could fail after a while, the car engines are using oil pressure between the bearings. For example, The crankshaft does not have any direct contact with the rest of the engine, it uses a thin oil film between the metals made by the oil pressure. Because of this, the metals will not have direct contact with each other and the bearing will not get worn.
But if your oil pressure drops low, the bearing could get in contact with the crankshaft and wear the bearing down. If this happens too often the bearings play will get too big and the oil will just pour out and your engine will get destroyed really fast. This process can go really fast if you have low oil pressure.

On the picture, you see crankshaft bearing that is fitted between the crankshaft and the engine block.

 

What could cause low oil pressure at idle?low oil pressure

There are several causes of low oil pressure at idle. The first thing you should check is to make sure that the oil pressure gauge is showing correctly. You may have a good oil pressure but the oil pressure sensor/gauge is giving you the wrong value. This should be checked with a mechanical pressure gauge to get the most accurate result. An example of this is the 8milelake Oil Pressure Diagnostic Tester Tool Set. Always check the instructions on how to connect it to your vehicle.

If you have checked your pressure with a mechanical gauge and it’s confirmed that the oil pressure is low, there are several causes that have to be checked.

1. Low oil level

If you have low oil pressure at idle, make sure that your engine’s oil level is correct. Check your dipstick and make sure it’s not under the MIN mark. If you have a low oil level, the oil pump can suck up air from the sump and make a low and fluctuating oil pressure. If you do not know how to check your engine’s oil, check your repair manual or leave a comment down below.

2. Wrong type of Oil for your engine

The oil you use in your engine could cause a low oil pressure for your engine. If you are using a 0w-20 oil on an engine that requires 5w-50 oil you could get a low oil pressure when the engine is hot. Some engines do have a larger bearing play and require a thicker oil to get the correct oil pressure at idle. If you have low oil pressure and you suspect that you have the wrong oil in your car, check your repair manual of what oil you should have and make an oil and oil filter replacement.

 

3. Dirty pickup to the oil pump

If your oil level is correct and you are making sure that the oil type is correct, the most common cause of low oil pressure is too much dirt in the pickup to the oil pump. Normally the oil pump is taking the oil from the bottom of the oil pan from a pipe. Before that pipe, there is often a net that will prevent any big metal pieces to go through the oil pump. That filter/net could catch a lot of dirt and may have to be cleaned. To check this, you have to remove the oil pan from your vehicle and inspect the oil pickup.

4. Damaged Oil pump

If the oil pickup filter looks fine there could be a damage to your oil pump. To diagnose if your oil pump is damaged is not very easy and often pretty hard to replace the oil pump. If you are lucky the oil pump is fitted inside the oil pump with a chain to the crankshaft and then it is much easier to replace. If you are not a very skilled mechanic you should let a mechanic diagnose to see if it’s a faulty oil pump. Ask your authorized dealer or check your repair manual to find where the oil pump is located and how hard it is to replace it.

5. An internal oil leak or damaged bearings

In rare cases, there could be an internal oil leak inside your engine. It will make your oil pressure low and it could leak from a crack or a bad internal gasket. Another problem could be that you bearings are already gone, but usually, you will hear a noise from the engine if the bearings are gone. These problems are not very easy to diagnose yourself if you are not a skilled mechanic.

 

Summary

  • You should always check that the oil pressure sensor/gauge is correct before you are starting to diagnose the cause of the low oil pressure.
  • If you have low oil pressure you should always make sure that you have the right oil for your engine. Check your repair manual or call your authorized dealer
  • Low oil pressure will cause permanent damages really fast if you are unlucky.

If you have High oil pressure. Check this article out: Causes of High Oil Pressure

If you have any other questions about your oil pressure or you have a story of how you fixed your vehicle, comment down below and I will answer your question as soon as possible. If you have any other car questions you can ask us at our homepage for free.

 

 

 

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Comments

  1. I have a 1.3 Toyota tazz, I’ve done an engine overhaul and all parts have been fitted correctly. My problem is that the oil pressure is too low at idle and I don’t understand what went wrong. New oil pump, pressure valve, oil filter and new oil,oil pickup is cleared and clean…. If engine is reved, oilite goes off but then when idled comes back on and there’s noise on engine. Plz help..

    1. Author

      @Patric Check the crankshaft rod and main bearings if you haven’t. If one is damaged, the pressure can pour out and it will result in a low oil pressure.
      Make sure you have the right engine oil and check the pressure with a mechanical pressure meter also.

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