An oil pressure gauge is an extremely important instrument to have when it comes to auto maintenance. Also sometimes referred to as an oil gauge, they measure the engine oil pressure to make sure that there is the right amount of PSI (pounds per square inch). This is very useful for making sure that there are no oil leaks.
If you suspect that there is any oil leaking out, it’s imperative that you pick up an oil pressure gauge kit and check the pressure as soon as possible. You’ll need to figure out whether you really have low pressure or if it’s a problem with the sending unit.
If you ever hear any rattling or if the oil light comes one, turn off your vehicle as soon as you safely can. If you can get it home or to a garage, it’s best not to drive it again until the problem is solved, otherwise you could be doing irreparable damage to your vehicles engine.
Where Oil Pressure Comes from
Many people mistakenly assume that oil pressure comes from the oil pump. Actually, the oil pump is not what gives you pressure, it’s the resistance to the outlet of that pump that gives you pressure. All of the other components that cause any resistance in the flow of oil contribute to its pressure.
Will Replacing the Oil Pressure Pump Fix the Problem?
The mistaken assumption that it’s the oil pump that is solely responsible for pressure often leads people to replace the oil pump thinking that’s the solution. Although it occasionally does end up being a problem with the oil pump, nice times out of ten, it isn’t, it’s the engine. If you’re lucky, it will be the pump and will be a quick fix, but if you have an oil pressure gauge low reading, your car will probably need to have more extensive work done to it than simply replacing a pump. How much it will cost will depend on how bad the damage is, so be sure to take it to a good auto repair shop if you aren’t sure how to do it yourself.
The Difference Between a Mechanical and an Electric Oil Pressure Gauge
Of the two types of gauges, mechanical gauges are more trusted by experts. Some of that could just be out of stubbornness as auto mechanics tend to rely on the tools they’ve trusted throughout the years more. An electric or digital oil gauge allows you to skip the potentially hazardous copper tubing into your cockpit and replace it with a thin and simple electrical wire. Although electrical gauges are usually more expensive, they are safer and generally easier to install.
Both types of oil gauges are more or less the same in terms of accuracy. The difference maker is in the electrical sending unit, which can be more accurate than a mechanical unit’s plumbing. If you choose to install an electric gauge, you must replace the sending unit to ensure total compatibility, unless your existing sending unit happens to be fully compatible. The correct sender is usually included with the electric oil gauge when you buy it.
How to Install Oil Pressure Gauge
A common way to monitor your oil pressure is to actually install a gauge into your vehicle’s cockpit. Alternatively, you can temporarily connect a detachable instrument, which should take only minutes to connect depending on what type of vehicle you have. You may have seen cars that have a mechanical oil pressure gauge right on their dashboard or placed somewhere else near the driver’s seat. This is a somewhat common feature for owners of high performance vehicles to have. Though fairly common, some consider installing a mechanical oil pressure gauge into your car to be dangerous. When you think about it, having hot pressurized oil pumped through a tube into your car doesn’t exactly sound safe. Lines can bust and if that happens, oil will spray into your car, possibly even while you’re driving. That said, although there is a risk of this, it is uncommon. Installing a permanent instrument does however allow you to closely monitor your oil pressure at all times.
To set up a mechanical oil pressure gauge, install a copper line through a hole in the bottom of your car that is connected to the oil pressure gauge inside your vehicle. Copper is recommended over whatever kind of tube is included in the box when you buy your gauge (usually nylon) because it can handle high temperatures better and is more resistant to potential wear. You can buy copper tubing at virtually any auto or even hardware store that will fit, regardless of what kind of vehicle you are installing it on.
Tack on the taper or compression sleeve to one end of the line and screw on the fitting, and then screw it into your block. It’s important not to cross thread when screwing in your fitting. Tighten down the nut roughly one revolution from hand tight, or less. If you tighten it too much, it will damage the line. The other end of the line that connects to your oil pressure gauge should already be hooked up unless you chose to connect it to the block first. Place it wherever you want inside your vehicle. You can attach it with a zip tie and a couple of drilled holes as an easy improvised solution.
How to Check Oil Pressure in Your Vehicle
Hooking up a detachable gauge is obviously very similar to hooking up a permanent gauge, except you don’t need to pass a line into your car or anything like that. You simply hook it up to the block in the same way.
When you hook up your gauge and start your engine, the needle should be relatively steady. The pressure reading should obviously be increased when you increase the RPMs, but the needle should raise steadily. If it vibrates back and forth slightly, that’s okay, but if it’s got a lot of movement or if it’s bouncing around wildly, that means that somewhere you probably have an oil leak. Check for visible leaks in your connection as well as reading the oil gauge.
If the needle moves naturally with the RPMs up and down, that’s fine. If you can hear the rhythm of the engine and see the needle moving with it, that’s normal. Let it run for a while and take a look again. If the needle is still bouncing a bit but not wildly, your pressure might still be fine. It depends on how much it’s bouncing, and whether or not it’s reading the ideal amount of pressure for your vehicle. If the reading looks good, try replacing the sending unit or oil pressure sensor and see if the oil light goes out.
Higher viscosity oil like 10W40 or 10W30 will give a higher reading than 5W20 for example, so with an oil pressure gauge high reading, you should take that into consideration. You should really only be using the oil that the manufacturer calls for, but ultimately that’s a matter of preference.
Ideally, you shouldn’t have a reading of less than 10 PSI at idle, but if it’s close that’s probably okay. If you hook up the gauge and have no idea how to interpret the way the needle is behaving, then take it to an auto shop.
Here we’ve picked out the best oil pressure gauges to choose from that are available for sale online now. We’ve also included links to where to buy them the cheapest. Whether you need an electric or mechanical gauge, have a look below to find the best option for your vehicle.