Regular oil change discipline is an excellent habit. I’m a mechanic for twenty-plus years and if every car owner took the time (as you are) to just do the basics, I’d get a lot more fishing in.
Cheap oil filters have been designed to minimum specification and that is reflected in their cost. Using cheaper parts on a critical system such as engine oil supply is high risk and not advised.
In this article you’ll learn why using a cheap oil filter may be a highly risky choice. I’ll share with you the advantages of paying a few dollars more for an OEM (Original Equipment Manufacturer) filter and I’ll also show you my tips for changing your oil and filter.
Oil Filter Function
There’s more to a humble oil filter than you might imagine. The oil filter you use does make a difference, a quality filter is important. Filter types come in two flavors, the standard metal can or the pleated insert. The insert doesn’t carry the same responsibility as the metal can filter, but the quality is still important.
The standard oil filter screw-on type has a ton riding on it. It has three major roles and it must get them right, if it fails, so does your engine. The filters 3 main functions include:
- Filters oil
- Prevents oil drain back
- Allows oil bypass the filter when needed
Cleaning the oil obviously is important. Your engine contains fine metal particles and silica which occur naturally and need to be removed from the oil. These particles which act like liquid sandpaper, would if permitted eat away at components like bearings and camshafts.
The oil is pumped into your oil filter under pressure and passes through the pleated paper media, where it returns to lubricating the engine.
Anti drain back:
The latest-gen insert filters are not fitted with anti-drain back or bypass valves, these functions are built into the oil filter housing instead. The standard metal can filter is fitted with an anti-drain-back valve (silicone seal), this helps fight gravity by preventing oil flow back to the oil pan after shutdown.
If oil was allowed to drain back to the pan, the oil pump wouldn’t move oil quickly enough to prevent metal friction at startup and your engine would soon develop engine wear symptoms.
This is the metal filter’s final important job. Your car’s filter is fitted with a bypass valve and as its name suggests allows the oil to bypass the filter. The oil needs to bypass the filter when the oil is heavy, such as cold mornings or in case of filter media blockage.
The bypass valve is as you can imagine an important function, if the bypass valve fails, your engines a bag of bolts.
So the filter is as you can imagine not just a can with a screen, it’s engineered to take account of your car’s oil pressure and oil flow rate. The story doesn’t end there. The can and the seal need to be strong enough to withstand oil temperatures and pressures.
Components Of The Oil System
The oil filter is only one component, there are several more important components that all rely on each other for full function. The oil quantity and quality are what help keep the metal bits moving like butter and it is the most important component.
Most modern cars use synthetic or semi-synthetic oil grades which are super-efficient at cooling, lubricating and moving around your engine. They also contain a detergent that helps break down harmful acidic carbon deposits inside your engine. Synthetic oil is more expensive but it is far superior to oil.
In addition to oil and the filter, your car’s oil system comprises an Oil pan, Siphon, Oil pump; Pump drive; Galleries; Cooler (some cars), sensors.
The pump lives close to the oil pan and is driven by the crankshaft. The pump is the heart of the operation. It moves the oil from the pan to the top of the engine lubing all the components along the way. Typical oil pressure is about 15 psi (Pounds per Square Inch) at idle and increases with RPM proportionally. Oil pressure varies by engine size, engine wear, engine temperature, oil type used, and engine condition.
The oil pump is driven by the crankshaft, usually by chain and as part of the timing chain drive, but sometimes has its own chain. Some oil pumps are direct gear driven from the crankshaft.
The oil galleries are the passageways inside your engine which carry pressurized oil. The galleries lead to and terminate at moving components that require cooling and lubing, the oil then drains back to the oil pan under the force of gravity, where the oil pump once again moves it through the filter and on through the galleries.
The oil cooler isn’t fitted to all cars but performance engines or larger engines fitted to trucks will have an air to oil cooler fitted. The cooler which may be integral to the oil filter housing, uses coolant to help cool the oil. Other systems may use a small radiator bolted beside the coolant radiator that uses airflow to cool the oil. The oil is then pumped back to the engine via high-pressure hoses.
The Problem With Cheap Oil Filters
Using cheap oil filters really doesn’t make good sense to me. Oil is expensive, replacing an engine is expensive and even using an OEM filter will only cost a few dollars extra. Really don’t think it’s worth the risk. Cheaper filters are cheaper because they are made using lessor materials, it’s just that simple.
Here are a few of the problems I’ve experienced with cheap oil filters.
- Oil leak from oil seal
- Threads stripped
- Can burst
- By pass valve failed
- Drain back failure
- Media breakdown blocking oil galleries
- Media breakdown blocking timing chain tensioner
- Engine manufacturers warranty denied because of cheap oil filter fitted
Who doesn’t like to save a few dollars, but my advice – save money on cabin filters, car washes, polishes, air freshers but don’t save a few bucks where the downside of failure could cost thousands.
Fast Oil Change
If your changing the oil at home in your driveway, consider using a siphon instead of draining the oil through the pan. Removing the oil drain bung can be labor-intensive, you’ll typically need to:
- Jack the car up
- Lay on your back on the ground
- Remove the splash guards
- Remove the bung
- Lower the car to allow gravity do its work
- Jack the car back up
- Refit the bung with new crush washer
- Fill the engine with oil after changing the filter
- Run the engine
- Check for leaks
- Jack car back up and refit splash guards
If your car has an oil filter fitted top side, you won’t need to jack the car to change the oil. Using a siphon, suck the oil through the dipstick tube. This method is clean and reduces labor significantly but it has its shortcomings.
It won’t remove all the oil, fine silica particles held in the oil pan won’t be removed, the magnetic oil bung won’t be cleaned. While I don’t recommend using this method permanently, it is better than no oil change at all.
Do I need an expensive oil filter? Your car’s engine oil system is critical to engine life. As a mechanic, I recommend using only top-quality oil filters and oil.
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John Cunningham is an Automotive Technician and writer on Rustyautos.com. He’s been a mechanic for over twenty-five years and has worked for GM, Volvo, Volkswagen, Land Rover, and Jaguar dealerships.
John uses his know-how and experience to write fluff-free articles that help fellow gearheads with all aspects of vehicle ownership, including maintenance, repair, and troubleshooting.