How To Tune-up Your Ford Mustang: Basic Maintenance and Filters

For daily driven applications, most Mustang owners run their tire pressures between 30-35psi. Incorrect tire pressure can cause uneven tire wear, and can also affect gas mileage. You can find the optimum pressure by inspecting the tread wear periodically. Even wear is the main goal. If the center of the tread is wearing faster than the rest of the tread, reduce pressure by 4-5 psi. If the outer edges are wearing more, increase pressure by 4-5 psi.

There are other important aspects to inspect on your Mustang wheels as well. Located on the outer or inner lip of the rim are your wheel balancers. These are located at precise points on the rim to ensure proper rotational balance. If they are missing, the tire can produce a rumbling or roaring noise, and sometimes a slight shake in the steering wheel. Make sure these are intact, and occasionally have them rebalanced by a qualified tire shop.

When inspecting your tires, make sure to check for any nails or other sharp objects that may be lodged in the tire. Confirm the valve stems (the rubber nipple you use to inflate or deflate your tires with) are leak proof. Move them back and forth gently with your finger and listen for air leaks. If you suspect there may be a slow leak in your tire, spray the area suspected with a soapy water mixture. If there is a leak you will see large bubbles forming where the air is escaping.

With modern day emissions compliant and fuel injected Mustangs, spark plugs last much longer than in the past. However, if your high mileage Mustang is still sporting the factory plugs, you may be wasting fuel, and putting a strain on the entire ignition system. It is important to periodically inspect the spark plugs for wear. On high mileage Mustangs with older spark plugs, the electrode of the plug erodes, increasing the plug gap. The condition of the plugs can provide information on how the engine is performing. For those with modded Mustangs, getting an aftermarket plug built to handle the added power is essential.

Coil packs don’t necessarily have to be replaced on a regular basis, but perform a simple inspection to ensure they are free of contaminants and the connections are firm. Plug wires don’t have to be replaced for long periods of time, however, inspections need to be completed. Specifically, make sure the jackets, insulation, and ends are not wearing and in proper condition. Additionally, making sure the wires have proper terminations and solid wire connections.

Spark plugs are relatively inexpensive. NGK, Ford Motorcraft and E3 all make quality spark plugs. Be sure they are gapped correctly for the application. In forced induction cars, the spark plugs must be checked more frequently. The combustion chamber conditions are a harsh environment for boosted or NOS cars. Therefore the spark plugs must be gapped smaller and inspected quite frequently, this is critical.

Tools needed: Voltmeter capable of reading 20 volts DC and less.

1. Select the voltmeter to read DC with a max value of 20 V or less.

2. With the car off, place the positive lead of a voltmeter on the positive post of the battery (red lead to red cable) and the black lead of the voltmeter to the negative post on the battery.

3. A fully charged battery should read 12-13 volts. Lower than 12 would indicate a weak battery, whereas under 11 volts indicates a failing (or failed) battery.

4. With the car running, the voltmeter should read 13.5-14.7 volts, indicating the charging system is working correctly. Any value higher than this would indicate an overcharge situation, and any value lower than 13.5 would indicate a discharge situation meaning the electrical system is unable to keep up.

The air filter is the starting point for all air entering the engine. Therefore, it’s exposed to all the elements. Humidity, dirt, grime, sand, etc. all bombard the air filter. Grit in the incoming air can damage cylinder walls, piston rings, and valves. An air filter that is too dirty can also cause excessive vacuum in the intake track. If you’re sticking with the stock paper filter, it’s a good idea to replace it with every oil change as this can affect the life of the engine and gas mileage. Many aftermarket companies such as K&N, JLT, and MAC produce reusable air filters for the Mustang. These usually can net a little extra horsepower and better fuel economy. These only require the periodic wash (with a hose) and oiling. Make sure to use the manufactures provided oiling kit, as it is application specific. Also, follow the directions they provide.

When cleaning your aftermarket air filter, be sure to let it completely dry before re-oiling and always use the correct type and quantity of filter oil. If you over-oil the filter, the excess will be drawn out of the filter by the engine, contaminating the MAF sensor, preventing it from working properly. Incorrect MAF readings will hinder performance and a contaminated MAF may even fail, costing you money.

One of the most commonly overlooked filters on a Mustang is the cabin air filter. This filter captures pollen, dust, and other pollutants that may make it into the cabin through the heating and cooling system. It acts as the first line of defense in keeping your blower motor clean and helps to keep the air that you breathe cleaner. A cabin air filter that isn’t replaced at regular intervals can reduce airflow into the cabin, stopping the HVAC system from working efficiently. An old filter can also act as a breeding ground for mold, which can irritate occupants of the vehicle and lead to some unpleasant smells. 

Filters are small and inexpensive parts, but your vehicle relies on them to stay running properly. Replacing, cleaning, and checking your filters regularly will keep your Mustang in tip-top shape for many years to come.

A big key way of maintaining the PCV valve on a Mustang is to keep up with oil changes. PCV is directly correlated with oil pressure. The older the oil is, the thicker it will become. This in turn makes it more difficult to pass through the PCV system and can potentially create blockages.

The more miles you put on your cooling system, the more corrosion it is exposed to. Extreme temperature changes and the exposure to ferrous metals can cause your coolant to pick up contaminants. This is especially true to Mustangs with cast-iron heads. Even with anti-freeze some oxidation occurs. You don’t want rust and iron particles building up in your radiator. This can lead to clogged coolant passages and overheating. Make sure the radiator cap is in good operating condition, if not just replace it as its pretty inexpensive. A proper radiator flush can be performed by a local shop and should be done annually.

A thermostat allows your Mustang's coolant to flow by opening or closing when the engine reaches a certain temperature. A fantastic way to maintain the thermostat is to keep an eye on the condition of the coolant itself. Coolant passes through the thermostat and having dirty coolant can clog the thermostat and prevent it from opening or closing. You can test the thermostat from time to time by putting it in water and then heating the water to the temperature where the thermostat would open. If the thermostat opens, then it is functioning as it should.

Your fuel system is made up of many small electronic parts with incredibly small ports which are prone to clogging and blockage. Without a reliable supply of fuel to your engine and proper spray pattern from the fuel injectors, your engine will struggle to make power and run properly. A blocked fuel system can even lead to a lean condition and engine failure. Dirt and grit in the fuel tank can also damage the pump, hindering its ability to flow an adequate amount of fuel. 

S550 Mustangs (2015-current) have an internal fuel filter, meaning it’s attached as a pre-filter to the pump, but they don’t have an inline filter like older Mustangs. Ford says the filter is a lifetime filter and doesn’t need to be replaced, but there are many options available for adding an external filter to your Mustang. Aftermarket filters come in various sizes for any fuel system, ranging from stock sized lines all the way to massive 10AN filters for big power fuel systems. They also offer filtration from 40 microns all the way down to 6 microns. Installing an aftermarket fuel filter can help supplement the cheesy stock filtration and protect your injectors from contaminants.

After a while, fuel filters get clogged from the dirt and debris from the gas pump. Changing the fuel filter can remove potential clogs and give you a solid peace of mind. Keeping your fuel clean and stabilized during the cold season can go a long way in making sure your pony doesn't turn up lame come spring time. Generally when you change out the fuel filter, it'll feel heavier than the new replacement because of the contaminants it's gathered over the years.

For the Mustang owner exposed to the extremely frigid temperatures of winter, it’s extremely important to be sure your Mustang is winterized. If your Mustang is going to be sitting in cold temperatures for an extended amount of time, use a fuel additive to your fuel tank. This will help to maintain octane and remove moisture from the fuel. If your Mustang will be exposed to sub-freezing temperatures, be sure you have fresh anti-freeze in the engine. The last thing you want to find is you freeze plugs lying on the ground beneath your stang.

Whether it be some small metal flakes from a brand new engine or catching outside contaminants, keeping the oil filter clean can keep the engine alive and healthy. Make sure to replace your oil filter during every oil change if you're doing them yourself. If you need more details on how to change your Mustang's oil, check out this guide.

Oil is the lifeblood of your Mustang's engine. It is pulled from the oil pan through the pickup tube by the oil pump. The pump then pressurizes the oil, forces it through the oil filter, and pumps it to the rest of the engine. This oil is used to lubricate the crankshaft, camshafts, provide pressure to hydraulic lash adjusters, run the Ti-VCT system (starting in 2005), cool the pistons (on certain models), and keep the pistons moving without scuffing the cylinder walls. Contaminated oil with dirt or other particles will slowly chew away at your bearings and eat away at the valve train. As these systems are damaged and wear further, they accelerate further wear from the metal shavings they generate.

Using a quality oil filter that meets Ford specifications will prolong your engine life and your oil life. Cheap or low grade filters use less filter media to capture contaminants. They also don’t have anti-drainback valves (ADVs), use cardboard instead of metal in vital parts of the filter, and have inferior pressure bypass valves. Anti-drainback valves and pressure bypass valves are critical components of a properly designed oil filter. Anti-drainback valves prevent oil from draining out of the engine through the oil galleys, preventing dry startups. ADVs help to prolong engine life by limiting cold start wear, which can be some of the worst wear on an engine. Pressure bypass valves help prevent a loss of oil pressure by allowing the oil to bypass a clogged or damaged filter. If they open too soon or too late, severe engine damage can occur.

Staying on top of your Mustang’s maintenance schedule will prevent major repairs in the future. These are all simple procedures to ensure your Mustang lives a long, healthy life. All it takes is a little neglect to send your precious stallion on a slow path to the boneyard. With a little maintenance and a careful eye, you can provide a long healthy life for your Mustang. Just keep the above tips in mind and you'll do fine:

• Keep an eye on your tire pressure for maximum mpg and to preserve your tires
• If you lose a wheel weight, replace it. Unnecessary vibrations only serve to cause headaches
• Watch for dry rotting or slow leaks from your tires
• Large spark plug gaps strain the ignition system. Replace them appropriately
• An air filter is probably one of the easiest items to replace. Keep your Mustang breathing freely
• Coolant should be replaced once a year to prevent it becoming too acidic and eating up your Mustang’s cooling system
• If your Mustang hibernates for the winter, don’t forget fuel stabilizer and other winter prep items