Low Oil Pressure At Idle – Causes & Fixes

We all know that motor oil is the lifeblood of the engine. It lubricates the reciprocating internal engine parts to offer optimal operation. It keeps the engine parts well-lubricated and protected.

There’s an internal engine part called an oil pump that helps to circulate the oil to every nook and cranny part of the engine. As a result, the engine oil will build pressure. This oil pressure is built when the motor oil is flowing through the oil galleries.

If there’s low oil pressure, it will cause accelerated wear if ignored and cause severe engine breakdown. This is why most motorists worry when they notice low oil pressure at idle only or when driving. Here, we’ll explain the causes and how to fix low oil pressure at idle. But before we proceed, kindly check low oil pressure symptoms for a better understanding.

low oil pressure at idle when warm

What Causes low oil pressure at idle

Oil pressure should always stay within the manufacturer’s predefined range. This means it should never go too low or too high. Older cars have an oil gauge indicator on the instrument cluster that shows the oil pressure range. It usually reads between 50 to 70 psi.

On the other hand, newer vehicles do not have an oil pressure gauge. Instead, they are built with an oil warning light that comes on whenever the oil pressure goes below 50 to 70 psi, depending on the car model.

Always pay attention to the oil pressure. If you have older cars with an oil pressure gauge on the dashboard, ensure the pressure needle does not go down to the danger zone. And if you have newer model cars, ensure the warning light is not displayed on the dashboard.

If the pressure gauge goes to the danger zone or the warning light pops up, pull over and see what could be the culprit. Ensure you do not continue driving the vehicle until you track and resolve the leading cause. What causes low oil pressure at idle anyway?

Low oil pressure at idle means the oil pressure is low when the engine is running at idle. The leading causes could be a defective oil pump, low oil level, bad oil quality, a lousy oil pressure gauge, or you’re running with the wrong oil type for the current weather or vehicle.

Poor oil quality

This commonly results from not changing the engine oil when you’re supposed to. If motor oil becomes dirty or contaminated, the quality starts to depreciate. It’ll start losing its cooling and lubricating properties.

The oil compounds change, and the cleaning additives used in the formation process dissipate. As a result, the engine will start building sludge.

Low motor oil level

If the oil drops below the recommended level, the oil pump may be unable to circulate the oil to every part of the engine, especially around the top cylinder. As a result, the related sensors will signal to the car computer.

The powertrain control module will then project the oil warning light, or the oil pressure gauge will start dropping to the danger zone to notify you of an underlying problem. The warning light will likely come up when driving through a corner or curve.

A low oil level can simply be an oversight or caused by a leak around the system. It could also mean the engine is burning oil. Low oil levels can also cause low oil pressure when warm.

Clogged or low-quality oil filter

Believe it or not, it’s better to use a high-end oil filter than high-end engine oil. I’m not saying you should use low-quality oil for any reason, rather my point is that you should not buy low-quality oil filters. A low-quality oil filter can easily clog and prevent adequate oil flow to the internal engine parts.

The Premium oil filter also clogs if you fail to change them at the oil service interval. Changing the oil and the oil filter is recommended for optimum engine performance. A clogged oil filter can also cause low oil pressure when hot.

Wrong oil grade

Like the oil filter, changing the engine oil with the wrong oil grade may lead to low oil pressure after the oil change. Undoubtedly, some engines can run on various oil grades, but some require a specified oil grade for optimal performance.

Depending on your engine, if the oil is too thick, it may not flow properly. While one engine may require a thin oil, another will require a thick oil for proper lubrication and cooling.

Faulty oil pressure gauge

A faulty oil pressure gauge may be responsible for low oil pressure at low RPM. This mostly happens after an oil change until the system resets and registers the new oil viscosity.

If this starts after an oil change and continues for an extended period, you need to examine the oil pressure gauge. It could be you have electrical issues. This can also result from a wrong oil grade, low oil level, or poor quality oil filter.

Lousy oil pump

The oil pump is an essential engine part that helps circulate the engine oil to every internal part in need of oil. If this component fails, it’ll stop circulating the motor oil. Once this occurs, the oil warning light will start flashing or stays lit on the dashboard.

You will hear strange clicking, tapping, or rattling noises inside the engine cylinder. Do not drive the vehicle with this sign, even for the shortest trip. Driving with a failed oil pump can lead to a catastrophic engine breakdown, requiring an overhaul or entire engine replacement.

Engine damage

In a worst-case scenario, it could be the car engine is damaged. Certainly, you don’t want this to happen. Yes, you can avoid this if you cultivate a regular maintenance culture.

If none of these probable causes are the leading cause, you need to check for other symptoms the engine is projecting for easier diagnosis. Also, scan the vehicle and pull out all the registered fault codes to check the meaning. From there, it may be easier to track and fix the root cause.

what should oil pressure be at idle

How do you fix low oil pressure at idle?

I know you’ll be wondering how to increase low oil pressure at idle. The simple answer is to track the leading cause and proffer a solution to it. Here are the possible ways to fix low oil pressure when idling.

Add more engine oil

Start the diagnosis by checking the oil level. Remove the oil dipstick and inspect the oil level. And if the oil is low, top it to the recommended level. In any case, you need to examine the oil condition and ensure it is still okay. You don’t want to add new oil to the existing oil that needs to be replaced.

Change the engine oil and the oil filter.

A dirty or contaminated oil will change the oil viscosity and may cause low oil pressure when hot on Chevy 350 and other car models. Always do your oil change at the recommended interval. Change the oil if it’s due for replacement or close to the replacement date. This may be all you need to fix the underlying problem.

Replace lousy oil pump

If a lousy oil pump is a culprit, the only option is to replace it. The replacement cost varies from vehicle to vehicle. On average, you should be ready to spend between $350 to $2,000 to replace a failed oil pump.

The cost varies so widely because replacing the oil pump on some vehicles may demand dropping the entire engine. In contrast, you can replace the component by just removing the crankcase in some cars. The part cost is another thing to consider.

Repair or replace the pressure gauge

If the oil gauge gives an unpredictable or erratic reading, there may be a sensor or electrical issue. This could be the only solution, especially if the engine runs smoothly without noise or performance issues.

To fix this, you need to properly diagnose the related car sensors and the electrical connections to the pressure gauge on the instrument cluster.

Use the recommended engine oil.

If you change the previous oil with the wrong oil viscosity, you’ll need to drain the oil and pour in the right oil. Start by checking the recommended engine oil in your owner’s manual. After that, get the right oil and replace the previous one. Ensure that you replace the oil filter again.

Fix engine issues

If engine damage is the problem or the actual issue leads to engine breakdown, you’ll either rebuild or replace the engine. This will drop expensive repair bills on the table.

You can also get a used engine if you’re on a low budget. However, there may be a short period or no warranty at all. Therefore, it’s better to make an informed decision before deciding what engine to go for.

FAQs:

Q: Why is my oil pressure low but oil level OK?

Low oil pressure doesn’t necessarily mean you have a low oil level. If the oil warning light blinks or stays lit on the dashboard, it could mean you have contaminated or dirty engine oil, failed oil pump, wrong engine oil, or a clogged or low-quality oil filter. Check these probable causes when diagnosing the leading cause of low oil pressure.

Q: What is a safe oil pressure at idle?

Safe oil pressure on idle is 20 to 30 psi. Something is wrong if the oil pressure runs below this psi when sitting. But on high rev, the oil pressure gauge should stay between 50 to 70 psi. If the pressure drops below this level, inspect the oil level, conditions, and other probable causes.

Q: Is 20 psi oil pressure good?

Any pressure below 20 psi on idle is considered low. On the other hand, anything below 50 psi on high rev is considered low. This is commonly caused by insufficient oil levels, dirty or contaminated oil, and defective oil pumps. However, other issues, such as the ones highlighted above, can also be the leading cause.

Q: Will adding oil fix low oil pressure?

As simple as adding engine oil, it will fix a low oil pressure if the culprit is low engine oil. However, factors like engine burning oil, worn piston rings, oil leaks, excessive blowby, and worn valve seals or guides can also cause low oil levels.

If any of these is the root cause of the low oil level, adding engine oil will temporarily fix the low pressure. But you’ll need to fix the actual cause to maintain a permanent fix.

Q: Is it OK to drive with low oil pressure?

Low oil level is a serious issue you won’t want to joke with. If you continue driving with a low engine oil level, the engine will incur catastrophic damages that may lead to overhauling or engine replacement. Contact a service technician to track and resolve the leading cause once you have low oil pressure.

Q: Will thicker oil increase oil pressure?

Some experts believe that thicker oil will increase oil pressure, such as increasing from 5w-20 to 10w-30; I advise you to take this with a grain of salt. Well, this slight change may increase the bearing clearance, enhancing the oil pressure.

Q: Can a clogged oil filter cause low pressure?

A clogged or dirty oil filter is one of the common causes of low oil pressure. If you just replace the oil filter, chances are you bought an inferior filter, which is as bad as a dirty filter. Oil filters have oil relief valves. If these valves fail, the motor oil will pass right through, reducing the oil pressure.

Q: How much does it cost to fix low oil pressure?

It is nearly impossible to accurately estimate the repair cost of low oil pressure. This is because several factors are to be considered. However, the cost of fixing low oil pressure can be as little as $20 or as high as $2,000, depending on your car’s make and the root cause.

For example, if the solution is to add extra oil to the engine, it won’t cost more than $20 to fix it. But if the root cause is a failed oil pump, then you should budget to spend between $350 and $2,000. You may even pay more if the problem has damaged internal engine components.

Final Words

Several factors can cause low oil pressure at idle. Once this happens, the oil warning light will illuminate the dashboard. With or without the oil warning light or the oil pressure gauge reading, do the needful by performing regularly scheduled oil changes and other car maintenance.

Osuagwu Solomon

Osuagwu Solomon is a seasoned automotive technician for the past 9 years, and a technical writer. He loves writing about auto professional repair guides, DIY repair guides, and buyer’s guide. After spending six years in the automotive workshop, he decided to impact his knowledge to people aside his domain, and he has achieved this by centering his Automotive writing skills on REPAIRS.

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