Stability is the secret to a car engine’s performance and lifespan. Keeping everything in balance, including oil pressure, is essential. High oil pressure is one of the engine’s vital signs and can lead to total engine failure if left unchecked.
Like blood pressure in a human, good oil pressure in your engine is necessary to ensure the lubrication of vital components like the camshaft and the balance shaft bearings. Sufficient lubrication is required to reduce wear and tear on these critical parts and stops the engine from getting too hot.
If you get a high reading from your dashboard oil gauge, it is time to investigate the problem and make the required repairs.
What Is A Good Oil Pressure?
High oil pressure is created when the force required to circulate the oil in the engine increases. Nowadays, most cars have an oil pressure gauge that shows the pressure required to push the oil through the engine. Around 20 minutes from starting the engine from cold, the oil gauge’s needle should be sitting at the halfway mark.
When the engine oil is warm, the ideal oil pressure should be in the range of 25 – 65 psi. If the oil pressure indicated is 80 psi or more, it means there is a severe problem that needs your immediate attention.
The Impact Of Low and High Oil Pressure on Your Engine
While oil pressure is a vital indicator of an engine’s health, a better marker is ensuring that adequate oil is passing through engine components. Up to a point, low oil pressure is good. High oil pressure, conversely, is always a terrible sign and detrimental to the engine. Suppose you see a high-pressure reading being indicated by the oil gauge. In that case, you should be quite concerned about the health of your vehicle’s engine.
As pressure is a measure of flow resistance, low viscosity oil in broad engine oil channels will result in a fast flow rate and a low oil pressure reading. This scenario decreases engine wear and is a welcome outcome.
In engines with narrower oil channels, the opposite will be seen when fed high viscosity oil. High oil pressure may become inevitable, with adverse effects upon engine lubrication. In extreme cases, engine components will be subjected to increased wear if they do not receive the necessary oil. In certain engines, the oil may travel through a valve only to be sent back to the oil pump. This nightmare scenario will result in moving engine parts receiving none of the oil they need to function correctly.
What Causes High Oil Pressure?
A clogged up oil passage is often the culprit responsible for high oil pressure. The longer the blockage is in place, the higher the likelihood of engine lubrication being compromised. Often an oil leak at the cam housing is a sure sign of a blockage. This type of oil leak is sometimes referred to as a lifter tap. The blockage occurs when carbon deposits or sludge build up in the oil channels, a consequence of burning fossil fuels. Eventually, these deposits merge with the oil and thicken in texture. The presence of this debris inside the oil passages can cause bearings to fail over time.
Clearing blocked oil channels is difficult and expensive and requires specialized tools and meticulous attention to detail. The elaborate process involves flushing the complete engine lube system to ensure all the debris gets removed. This top-down procedure involves cleaning hoses, cooling jets, orifice dowels, plugs, and auxiliaries. A petroleum-based solvent is used for cleaning the oil passages in conjunction with professional brushing equipment. This is a mere ‘scratch the surface’ explanation; there are far more steps and intricate procedures involved to get the job done.
Blocked Oil Filter
An oil filter, by the nature of its job, gets dirty and clogged up eventually. Maintaining the engine oil’s cleanliness involves filtering out tiny particles and other impurities to ensure the engine gets lubricated correctly. The oil filter eventually starts getting blocked up through continued use, which consequently reduces the oil flow rate through the filter. When there’s a drop in the flow rate at the oil filter, engine temperatures will increase. The engine temperatures rise causing high oil pressure in your engine.
Warning signs of an overdue oil filter change include:
- Performance – If you are down on power with your vehicle not picking up the pace properly and the accelerator being overly hesitant, then there’s a metaphorical spanner in the oil filter works.
- Spluttering – Another indication that all is not well with your oil filter. Spluttering happens when an insufficient volume of oil is circulating. With low oil levels in the system, your car will have difficulty accelerating smoothly. This spluttering may be minor at first but will as time goes on get gradually worse. The solution is to replace the oil filter.
- Metallic noises – These noises are your engine complaining about the lack of oil. With insufficient lubrication, there’s increased friction on the engine. The metallic noises are being made by parts rubbing together due to the increased friction caused by low oil levels. If you hear these death rattle noises while driving, pull over, and switch off as soon as you can safely do so to prevent further damage.
- Black soot – If you see sooty, black exhaust fumes, this is another red flag. Dirty exhaust emissions accompanied by a smell of burning oil are never good news. In fact, that distinctive burnt oil smell means it’s time to call your auto repair shop and make a reservation for your car to have its oil filter replaced and any residues removed from the oil system.
Today, though, some cars are fitted with reusable oil filters containing a stainless steel core, so you may not even be required to buy a new oil filter. However, this filter type is usually fitted to high-performance vehicles to filter out fine particles and is given a good clean out during scheduled oil changes. Other less sporty vehicles may still be using single-use filters.
The usual cause of high oil pressure is engine temperature. A cold engine at startup and during idling will provoke high oil pressures due to the engine’s cooler temperature. When you begin driving, the engine temperature begins to rise. As the engine reaches its average working temperature, the oil heats up too. It can then flow more quickly through the engine’s oil system. The engine and oil heat up together until they reach their optimal temperature. When you switch off your engine, the opposite occurs; the oil cools down in step with the engine.
The type of oil you buy for your engine can also contribute to high oil pressure. Thinner, lightweight engine oils are designed for low oil pressure as they can flow more easily around the engine. Thicker, stickier oil, on the other hand, require high oil pressure to lubricate the engine correctly. Broadly speaking, an increase in oil pressure after changing to a different oil brand means your previous choice of oil was too thin to provide optimum performance.
You can select the right oil for your engine by following a few simple rules of thumb.
First up, check your owner’s manual for the recommended oil type for your vehicle. Then alter the weight of oil to suit your weather conditions. A good benchmark for quality is engine oil that has been approved by API (American Petroleum Institute).
Next, you have to choose between regular engine oil and a synthetic alternative. A reputable oil brand will sell a range of oils with varying levels of viscosity. They are called service level oil (SL). For example, a 5W-20 oil is designed to operate in lower temperatures. In contrast, a 10W-30 oil is best for places with a higher ambient temperature. Meanwhile, fully synthetic oils are meant for high-performance engines and tend to last longer than other oils. They are specifically formulated to protect against engine deposits, flow better at low temperatures, and provide premium lubrication at high engine temperatures.
Faulty Oil Sending Unit
Your dashboard gauge reading depends on the oil sending unit for its information. A faulty sending unit will cause the gauge to display incorrect pressure readings and should be replaced or repaired. Inaccurate oil pressure readings also sometimes spark off other warning lights like the oil pressure light repeatedly blinking. A flickering oil pressure light typically means the oil level is too low and is picked up to avoid engine failure.
Before investigating the oil sending unit, always manually check the oil level first. There are various tools for troubleshooting a sending unit, including digital multimeters, scanning tools, and mechanical gauges to check the oil pressure. Dial-in the resistance range first before using a multimeter. You should obtain a reading of 240 Ohms if the sending unit is working correctly. If you see a different reading, it’s conclusive proof that the sending unit is defective and feeding garbage high oil pressure signals to the gauge.
Relief Valve Issues
The relief valve’s task is to prevent high oil pressures causing damage to oil pipes or vessels. Relatively unsung as a component, the relief valve plays a significant part in the internal combustion engine by regulating the oil pressure. A faulty relief valve is a prime suspect if you fire up the engine, start driving, and the oil pressure never reaches its optimal level. In this instance, the relief valve should be removed, cleaned up, and refitted. If the oil pressure is now sitting where it should be, you can safely conclude the problem was with the relief valve.
Switching Oil Grade
Experimenting with different grades of oils is never a good decision
when it comes to your engine’s well-being. Oils have different levels of viscosity or thickness and are designed to meet specific engine needs. Always check the car manufacturer’s recommended grade of oil in the owner’s manual, or consult with an expert for guidance.
Numerous variables are involved in recommendations regarding oil viscosity. However, the general guideline is that the oil must be able to circulate freely around moving engine parts while at the same time adequately lubricating the spaces between the parts. It is rather like jigsaw pieces fitting together neatly.
On the one hand, thinner oil tends to do a much better job of moving freely through the engine. The caveat is that the space between the parts was purposely designed for this kind of oil. By contrast, thicker oils were engineered to fill larger spaces. This thinking, however, is, to an extent, old hat nowadays. Today, those larger engine spaces are no longer in play. Now, oil flow volume and oil pressure are affected when thicker oils are introduced into an engine without those voids to fill.
Thicker oils, too, have a reputation for increasing oil pressure, which is regarded as a negative if it’s price tag is decreased oil flow volume. It is worth noting that viscous oils have repercussions. Firstly, the oil pump needs to work harder to pump the denser oil around the system. In turn, this causes oil pressure to increase and the flow volume to drop.
Why is Replacing the Engine Oil Important?
Ignoring the health of the oil lubrication system can frequently come with a hefty price. Lack of oil system maintenance can and does lead to a host of engine-related trouble you should try to avoid. That is why sticking to the oil change schedule is so essential and unavoidable. Over time engine oil will inevitably breakdown and become thick, causing the oil to lose viscosity. This breakdown can also result in low oil pressure.
Conversely, higher oil pressures occur when the oil thickens up due to low temperatures, something you should be on the lookout for when you live in a colder region. Also age-related is the residues resulting from metal friction. As we have mentioned earlier, these tiny metal fragments can end up blocking your oil filter.
In conclusion, then, it’s critical to monitor your engine’s oil pressure and take note of any abnormal readings, indicating either high or low oil pressure. Radical changes to your oil pressure are always signs of a troubled engine. They should always be resolved as soon as possible to prevent further damage. It’s also vital to bear in mind that oil flow always takes precedence over oil pressure when checking that your engine’s lubrication system is up to scratch. What oil your engine drinks is also a vital part of the equation. It’s best to opt for a premium oil that has received the thumbs up from the American Petroleum Institute.