Symptoms of a Bad Oil Pump [How to Test and Fixes]

The oil pump is one of the essential complementary parts of your vehicle’s engine. Its primary duties are to supply the required oil for engine lubrication while the car is running. The lubrication oil allows the engine’s metal components to interact without causing tough physical damage due to friction. The oil from the oil pump also absorbs heat from the engine components bringing about a cooling effect and preventing the engine from overheating.

Although the pump is among the strongest parts of the engine, it sometimes malfunctions. A failing oil pump will starve the engine of oil and can result in catastrophic engine damage. Therefore, every car owner should note the symptoms of a bad oil pump and replace it to avoid worse damage to the vehicle.

Common Symptoms of a bad oil pump

There are several mechanical problems associated with a failing oil pump. Most of these mechanical problems have several conspicuous and easily noticeable indicators like increased engine temperature and strange noises during engine operation. Here are some common indicators of an oil pump that is progressively failing.

Symptoms of bad oil pump

1. Low Oil Pressure

As mentioned earlier, the oil pump provides and regulates the pressure of the oil that lubricates and controls the temperature of your engine. By pressurizing the oil, the pump facilitates oil navigation throughout the different parts of the engine. An adequate supply of oil ensures the moving parts of the engine are properly greased and efficiently slide against each other without physical damage.

Inadequate oiling due to low pressure from a bad oil pump causes the engine components to roughly rub against each other. The first signal of decreased oil pressure is the oil light on the dashboard powering up. Other consequences of decreased oil pressure are decreased power and engine stalling. Therefore, the answer to the question, can a bad oil pump cause misfires is yes.

2. Increased Engine Temperature

Lubrication oil reduces the engine temperature in two ways. First, it absorbs excess heat generated by the engine and dissipates it as it moves around the different parts of the engine. Also, lubrication oil decreases engine component friction. More friction results in higher engine temperature. Therefore, one of the symptoms of a bad oil pump is a significant increase in the operating temperature of your car engine.

When there is restricted oil flow in the engine and the engine temperature increases, your vehicle dashboard check light will light up to notify you of the alarming engine temperature. Vehicle overheating engines pose severe detrimental hazards to your engine. You should, therefore, take your car to the auto mechanic whenever you have overheating engine problems.

3. Hydraulic Lifter Noise

Other essential components of the valve-train operations of your vehicle engine are hydraulic lifters. They maintain the valve clearance with the rock and cam follower. Therefore, the lifters need enough oil lubrication to perform their function efficiently. Low oil pressure from the oil pump prevents the oil from reaching the hydraulic lifters. They will then struggle in mobility and produce a lot of noise when moving. Lack of lubrication causes extreme friction that leads to wear and tear, thus, significantly reducing the hydraulic lifters’ lifespan.

4. Noise from the Valve-Train System

The valve-train system of a car also includes important components like pushrods, seals, and valve guides that keep the engine running. Each of these components requires an adequate flow of oil for the lubrication of the metal parts. Inadequate lubrication causes friction to the mechanical parts of the engine, thus, the noise produced in the valve-train system. That is why noise production in the valve train can be a simple diagnostic for a vehicle with a bad oil pump.

5. Noise at the Oil Pump

A correctly functioning oil pump operates silently. However, when the pump begins to fail, it produces a whining and wiring sound when it attempts to circulate oil to the engine parts. The whining and wiring sounds are especially noticeable when the car is idling. The unfavorable sounds are due to the gears of the oil pump wearing out.

Read Also: Best Oil Catch Can Reviews

How to Test an Oil Pump

Having established that oil pump failure can cause critical problems to your engine, you should learn how to test oil pump failures so that you can replace the pump as soon as you notice any negative symptoms. Here is a procedure to follow to test for a failing oil pump.

Symptoms of a Bad Oil Pump

Stop Driving

Whenever you notice the low oil light indicator on the dashboard you should stop the vehicle and check the oil levels using a deep stick. Refill the oil when you notice the oil levels being lower than the recommended levels for your car. Restart your car and pay attention to the bad oil pump symptoms mentioned in the article.

Check the Oil Pressure Measurement Unit on the Engine

If the low-pressure light indicator on the dashboard remains on even after refilling the engine oil, there may be a problem with the measurement r communication system of your car. Bad communication is often caused by a loose hole where oil enters the system or a wiring problem.

If you don’t have a rheostat or other electrical problem and you notice weird noises from your car engine even after refilling the oil then you need to check the oil pressure of the running vehicle.

Check the Engine Oil Port Pressure Using A Gauge

Having established that your oil pump has issues because the dashboard light doesn’t turn off, correctly mount the oil pressure gauge on the engine’s oil port. Check and compare the pressure reading with the recommended pressure according to your vehicle type to check if there are any discrepancies. If your readings appear normal, then your sending unit is the one with the problem. If you have low-pressure readings then you should check and clean your oil filter before testing the pump again. If your problem persists, immediately contact a professional mechanic to replace your oil pump.

What Happens When an Oil Pump Fails?

Regardless of how durable the oil pump is, some oil pump failure causes oil contamination, progressive wear, tear, and malfunctioning suction tubes that are difficult to avoid. You should be on the constant lookout for the signs that your car needs an oil pump replacement.

When oil pumps start failing, you should expect to experience all the above-mentioned symptoms which worsen gradually and ultimately lead to complete engine destruction. With the reduction of pressure due to the oil pump, the bad oil pump or bearings will be under extreme pressure and will start collapsing. Without the oil pressure to fill the gap between moving metal components, there won’t be any wedge to keep these metal components from touching each other.

Vigorous contact dissipates massive levels of heat due to friction. This friction and heat will permanently destroy the components and wear away extra material from the engine. Inadequate pressure will destroy the connecting rod to crankshaft journal bearings quicker because these bearings are constantly under immense pressure from abusing forces. When these bearings are destroyed, and that clearance is increased, re-establishing oil pressure will be unhelpful because the oil wedge required for efficient operations can’t be recreated and the bad oil pump knocking will continue until the engine completely fails.

how to test oil pump

How to Fix Oil Pump Problems

The first step when you want to replace an oil ump is to disconnect the negative terminal of your battery. Lift the front of your vehicle using a jack while the car is on the parking brake. Drain all the remaining oil and remove the serpentine belt.

After draining the oil, rotate the engine for the first piston to be at the top of its compression stroke. Although different cars have different engine orientations, you should be able to look at the crank from the top and see a bracket through a rectangular window. Rotate the crankshaft to align the timing mark with the bottom of the window.

Now remove all the oil pan bolts of the engine. Also, remove the bolts that connect the oil pan to the transmission system. Locate and remove the bolts that hold the oil pump to the engine crankcase to leave it only attached to the timing chain. Free the oil pump from the timing chain by holding the pump and pressing the tensioner. You can also remove the oil pump sprocket using a T24 bit to leave it free.

After removing the old pump, thoroughly clean the surfaces using a brake cleaner and steel wool to remove any sludge or gasket residue.

Carefully set up the new oil pump taking note that the gear teeth are aligned to the timing chain. You can refer to your user manual for further instructions on how to correctly set up the pump.

You should then apply the right amount of sealant. Avoid applying excessive sealant, lest should it mix up and create impurities in the circulating oil. After sealant application, hold the oil pan and tighten the bolts holding it to the crankcase and transmission system.

Let the sealant dry for an hour or so, then fill your new oil pump with oil. Check that the timing aligns accurately by turning it several times using a ratchet. When everything checks out, lower the car and run it for a few minutes to check for oil leaks and ensure that your oil pump works efficiently.

Signs of a Bad Oil Pump failure Symptoms Noise and Leaks Low Oil Pressure YouTube

Bad Oil Pump Symptoms FAQs

Q: What happens when you have no oil pressure?

The low oil pressure light is a warning that there’s not enough oil pressure or that the oil level is too low. Low oil pressure means the oil will not be able to navigate the narrow engine passages to provide lubrication. Lack of lubrication can cause the engine to seize up or cause damage beyond repair.

Q: Where is the oil pump located?

The oil pump is the heart of the vehicle lubrication system. Traditional wet sump engines have a single oil pump that is located at the bottom part of the engine, either below or beside the vehicle crankshaft. Oil pumps are located close to the crankshaft because they are directly driven by the shaft to suck up oil from the oil pan and force it around the engine and back to the sump for recirculation.

Q: What does it mean when your oil gauge goes up and down?

Oil pressure fluctuation can be a normal operation for your vehicle. The oil pump is driven directly by the crankshaft, and the faster the car goes, the more the oil pump circulates, which leads to a higher pressure. However, not every pressure gauge is accurate, and fluctuating readings can mean that the gauge is faulty. It can also mean that you have low oil levels or a broken pump. The best thing to do when your oil gauge goes up and down is to get your car checked by a mechanic.

The mechanic may diagnose your engine with a blocked oil filter which causes high-pressure gauge readings. The mechanic can advise you to replace the filter and change the oil to fix the problem.

Q: Can a Bad Oil Filter Cause Low Pressure?

Oil filters are other significant parts of oil pressure regulation in a car engine. Using a faulty or wrong oil filter can cause clogging and substantial pressure drops. Efficient oil filters and relief valves allow adequate pressure regulation by preventing spikes in oil circulation. Malfunctioning filters will either provide too much or too little oil to the engine lubrication system. Therefore, a bad oil filter can lead to low oil pressure within an engine.

Q: How long does it take to change an oil pump?

The time you need to replace a faulty oil pump depends on your skills, experience, and the efficiency of your mechanic tools box. Although you can save a substantial amount of money by changing it yourself, we recommend that you employ the services of a qualified mechanic to change your oil pump. An experienced mechanic will need a little over an hour to replace your oil pump.

Final Words

An oil pump is one of the most essential parts of a vehicle’s engine. It provides oil in the required pressure levels for adequate lubrication of the bearings and other mechanical parts of the engine. In addition to providing lubrication and allowing the mechanical engine parts to rotate efficiently, the oil is also responsible for temperature regulation to avoid overheating. Therefore, every car owner should watch out for damaged oil pump symptoms to avoid unprecedented mechanical damage due to low oil pressure.

Osuagwu Solomon

Osuagwu Solomon is a certified mechanic with over a decade of experience in the mechanic garage, and he has over five years of experience in the writing industry. He started writing automotive articles to share his garage experience with car enthusiasts and armature mechanics. If he is not in the garage fixing challenging mechanical problems, he is writing automotive repair guides, buyer’s guides, and car and tools comparisons.

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