In order to perform a tune up on your vehicle, you will need an assortment of tools to get you rolling and you will also need some tune up parts, as well as the knowledge and proper training to replace these parts.

Let’s begin with some parts that we will need in order to perform a proper tune up on today’s vehicles.

• Air Filter
• Oil Filter
• Engine Oil (Correct Viscosity!)
• Spark Plugs
• Spark Plug Wires
• Distributor Cap
• Ignition Rotor
• Fuel Filter

Some vehicles are also equipped with an Air Cabin Filter. If your vehicle has one, it should be checked for moisture & whether or not it’s plugged, the Air Cabin Filter housing must be cleaned of any debris to help keep the vehicle inlet air clean.

Checking & Replacing Parts

Air Cabin Filter – If equipped, locate the Air Cabin Filter housing. It is usually under the dash on the passenger side or under the hood near the rear of the cowl. If moist, customer complaints may include odd odors in the vehicles cabin and the filter should be replaced and the housing needs to be cleaned. If plugged, customer complaints may include lack of air flow into the vehicles cabin and the filter should be replaced.

Air Filter - The air cleaner in your vehicle should be changed every 3,000 miles or sooner depending on driving conditions. If you’re often driving in dusty conditions, the air filter should be checked regularly and replaced or cleaned as necessary.

Oil & Filter – The engine oil & filter should be replaced at regular intervals of around 3 months, or 3000 miles. The idea behind that recommendation is to replace the engine oil filter before it is clogged and to replace the engine oil before it can no longer protect your engine to the best of its ability.

Spark Plugs - A spark plug is used to ignite the fuel air mixture inside the combustion chamber. If a spark plug becomes worn or damaged it can cause poor performance and fuel economy and should be replaced at a manufacturers recommended mileage.

Spark Plug Wires - Each spark plug wire is connected to a spark plug, and brings the electrical spark to the spark plug in order to ignite the fuel inside the engine’s cylinders. A damaged spark plug wire can make your car run rough and affect gas mileage. Remember to replace spark plug wires ONE at a time so as not to cross wires! Keep in mind that not all ignition systems are set up the same but they operate on the same principle. Some vehicles have a Direct Ignition system consisting of a coil over the spark plug (COS) and spark plug wires are not required!

Distributor Cap & Rotor - The distributor cap and rotor are two essential pieces that distribute electrical current to the spark plugs. The distributor cap connects to the spark plugs directly using a spark plug wire. The rotor is designed to spin inside of the distributor cap, just missing the terminals inside the cap. A worn or damaged rotor can cause your vehicle to run rough, or even stall completely. The rotor is rotating at the same speed as the camshaft which also happens to be 1/2 the speed of the crankshaft.

A problem occurs when the contacts inside the distributor cap become dirty or worn. It is good practice to replace the distributor cap and rotor during every tune up to ensure the contacts are clean to transmit power to each spark plug.

Fuel Filter – A vehicles fuel filter is used to keep the fuel in the fuel system clean to prevent debris from entering the fuel injectors or fuel pressure regulator. The fuel filter should be replaced during every major tune up or every 25,000 miles.

Let’s move onto another aspect of a complete tune up.

Throttle Bore Service

Vehicles that have an air intake system should also undergo throttle bore service or inspection during any tune up. It is just good practice. The air intake boot should be removed from the throttle bore and the bore inspected. If there is any signs of coking (build up of carbon, dark but light tar residue), the throttle bore should be cleaned out. Rubbing alcohol works really well or a commercially available solvent can be purchased.

“Coking” can be the cause of a ‘sticky’ accelerator pedal, engine stalling, odd engine idle or even poor fuel mileage.

Remember, when a customer comes in and specifically requests a tune up, it is good practice to talk with the customer and find out if there are any driveability issues they are trying to resolve. It is possible that they have other issues that may not be repaired during the tune up and this will result in a poor customer relationship from the start.

A good attitude and good customer service skills are the most over-looked skills that makes a good technician, a great one.

Almost all drivers have witnessed it. A vehicle that has smoke just pouring from the exhaust system. Just this morning, I saw it myself, which is what inspired me to write a little bit about how to “self-diagnose” exhaust smoke and what the different colors of exhaust smoke can mean.

The vehicle I saw this morning on my way to work had bluish-gray smoke clouding up road right in front of me at an intersection. So I figured this would be a good starting point. A blue-gray or gray-white colored smoke says that the engine is burning oil. One of the first systems a home mechanic should look at under these circumstances is the Positive Crankcase Ventilation system, or PCV system for short.

When your vehicles engine is running, combustion gases can leak right past the piston rings and wind up in the crankcase. Typically, this is what’s called “blowby”. The PCV system vents these gases into the air intake and are then burned off with the air / fuel mixture. The PCV system keeps the engine oil clean by removing moisture and harmful fumes from the crankcase and also keeps the crankcase from over-pressurizing, essentially preventing oil from pressing it’s way past gaskets and seals. Keeping the PCV system clear and operational is very important!!

The more common causes of burning engine oil are worn valve guides, seals, piston rings or even a worn cylinder. Diagnosing these issues are somewhat complex and requires some equipment. My recommendation here is to bring it to a repair shop and they will probably recommend a Cylinder Leakage Test. The results from this test will determine whether the issue is in the cylinder head or within the block and plans for a repair can be made.

Black exhaust smoke says that the air / fuel mixture is running too rich. If your vehicle is smoking black, most likely the problem is not mechanical. Black smoke can be caused by a faulty fuel injector, a leaking fuel pressure regulator diaphragm, a cracked or broken air intake boot or a sensor giving faulty readings to the on board computer and in turn, the computer then adds more fuel than it should. The home mechanic should check the fuel pressure regulator first.

This component regulates fuel system pressure by using a diaphragm and spring combination. If the diaphragm breaks, it lets raw fuel escape into the vacuum feed line, the raw fuel then makes its way into the intake system of the engine creating a rich black smoke from the tail pipe at engine start and during operation. In order to check the diaphragm, you should take the vacuum line off of the fuel pressure regulator and check for fuel. If fuel is found, the diaphragm is past it’s usefulness and should be replaced. On most vehicles, the fuel pressure regulator is in plain sight at the top of the engine, right on the fuel rail. Others may have an internal intake regulator and the upper intake needs to be disassembled in order to inspect it. In this case, I would recommend that you bring your vehicle to a repair shop.

The home mechanic can also inspect the air intake boot. This boot routes air from the mass air flow sensor to the throttle bore. The mass air flow sensor meters the air flowing through the air intake boot and adjusts the fuel input accordingly. If the air intake boot were to fail, un-metered air gets into the intake and the wrong fuel adjustment is made by the Engine Control Module or ECM, it adds more fuel than necessary, creating a black smoke from the exhaust. To check the air intake boot, remove it from the vehicle and inspect it for cracks, tears or rips. If one is found, the boot needs to be replaced.

White exhaust smoke, in excess, typically means that there is coolant leaking into one or more cylinders. The white smoke is created by the engine trying to burn the coolant off. The most common cause of excessive white smoke is, but is not limited to, a bad head gasket. The first step to take is to pressure test the cooling system. Attach a pressure tester to the coolant filler neck and apply pressure equal to the pressure rating marked on the radiator cap - given that the cap is the correct cap! If after you pressurize the system, and the pressure begins to drop and there are no signs of an external coolant leak, this indicates that we do have an internal coolant leak.

Next, a home mechanic should perform a cylinder power balance test followed by a compression test. A compression test should be performed with the engine at operating temperature and with every spark plug removed to let the engine crank a bit easier.

The results of the cylinder power balanace & compression tests should narrow down the area that has damage. Keep in mind that the catalytic converter can keep a small internal coolant leak masked until it gets bad, as it can super-heat the water to such a fine vapor that it may not even be noticeable, at all. Also, any leak from the cooling system into the intake or combustion areas can cause white smoke. It may be caused by a defective intake manifold gasket, timing cover gasket, blown head gasket or even a cracked cylinder or or cracked engine block.

Symptoms will vary depending on how bad of an internal coolant leak we have. When coolant leaks into a cylinder, it could create a white smoke from the exhaust system and also carry a sweet anti-freeze odor. It could also cause a cylinder misfire, more so when the engine is not at operating temperature. If coolant is leaking into a cylinder, this means that combustion gases can escape into the cooling system! One thing to check here is to look for big air bubbles in the radiator coolant while the engine is running.

Once the source of the leak is found and repaired, it’s always a good idea to test the oxygen sensor(s) for correct operation, or other driveability issues may remain.

Why do I need an engine oil & filter change?

This is one of the more common questions that I am asked on a relatively regular basis. To understand the answer, it is important to understand the requirements under the hood. Within your vehicles engine, there are many metal surfaces that rotate, pivot or otherwise move very close to one another at high speeds. The primary goals of your engine oil are to keep those surfaces lubricated and cooled.

During engine operation, the engine oil is pushed through the engine oil filter in an effort to keep the oil free of contaminants. The filtered engine oil is then used to coat and lubricate moving parts, absorbing heat and washing away chemicals and other build-ups. The engine oil is then recycled through the engine oil filter, where the impurities are trapped, keeping them from cycling back through the engines crucial parts, minimizing premature parts wear.

The stress put on the oil in your engine is very hard to imagine. It is subjected to an immense amount of heat and pressure, it cleans an engines internals of chemicals such as silicon oxide along with other by-products and eventually, the stress becomes too much and the oil begins to break down on a molecular level. By this time, the engine oil filter is clogged and at the end of its usefulness.

Ideally, it is recommended to have your engine oil changed every 3 months, or every 3,000 miles. The idea behind that recommendation is to replace the engine oil filter before it is clogged and to replace the engine oil before it can no longer protect your engine to the best of its ability.

So, back to the question at hand, why do I need an engine oil & filter change? An engine oil & filter change is an inexpensive and quick operation and is widely considered as the most important preventative maintenance that can be done to your vehicle.