For modern electronically controlled engines ‘tune-up’ is a bit of a misnomer. First a bit of history. Before electronic ignition systems that where pioneered by racers, we had the traditional distributor with points and condensers. The points were cam driven and opened and closed according to the lobes and the distributor was driven from the camshaft at ½ the rpms of the crankshaft. As the points opened an electrical arc was created and over time the points became pitted and the nylon rubbing block of the points that were in contact with the distributor cam became worn. This necessitated the replacement of the points and condenser that absorbed the power and discharged it to fire the plugs. Because of the lower voltage and other factors, the spark plugs would burn at the gap contacts and need replacing every 30,000 miles or so. Modern electronic ignition systems did away with the need to replace components as there is little mechanical operation involved. Higher voltages enabled the plugs to burn cleaner with less electrical erosion and fuel mixtures where optimized to prevent fouling. Spark plugs still can be replaced but will go 60,000-75,000 miles. There are no points and condenser to trifle with. The carburetor idle fuel mixture adjustment associated with a tune-up are things of the past as all the running engine parameters are electronically controlled with no means for manual adjustments. Even timing checks are no longer needed as there are no timing marks for comparison. However, on occasion replacement of fuel filters, spark plug wires and fuel lines are still viable as these due deteriorate over time.
Modern Car Tune Up Procedure
So what constitutes a modern tune-up?
• Battery and charging voltage. Onboard electronics, and there is a bunch, need to have a reliable power supply that is within specifications for minimal operation.
• Power balance (compression check). This identifies leaky cylinder valves, worn rings, leaking or bad head gasket, bad cam and other engine mechanical parameters affecting engine performance.
• Check engine vacuum. The engine creates a vacuum according to the throttle opening. Power brakes and windshield wipers a few of the mechanical components that depend on engine vacuum. This check would identify leaking intake gaskets and other leaking components of the upper engine area. Operation of the fuel feedback control loop to confirm closed loop operation during warm-up.
• Scanner diagnostic codes list: With the modern electronic systems the advantage is that they are self-diagnosing. They create and store a list of codes that allow identifying of engine problems, including exhaust emissions.
• Check engine timing. If there is provision for it, check the operations of the EGR (exhaust gas recirculation) this reduces nitrous oxide (NOx) emissions.
• Rubber check. Check all rubber-based components for cracking and/or leaks. This includes all hoses and belts. They oxidize, operate in a high heat environment and will break down over time.
• Fluid check of all the liquids used for engine and vehicle operation. Brake, washer, coolant (radiator), power steering, automatic transmission fluid and engine oil. If the ATF (automatic transmission fluid) smells like burnt toast you have a problem. Metallic particles or sludge in the engine oil should raise some concerns as well. Brake fluid should be clear and not full of muck and the antifreeze level and no particles in the coolant system.
Car Part Replacement
Components that may have to be replaced after a car tune up include:
• Spark plugs – you may want to consider long life plugs on the market.
• Rotors and distributor caps are still present on some vehicles.
• Fuel and air filter. PVC valve, as needed you may want to replace spark plug wires, belts, hoses and top off fluids.
• Check ignition timing and idle speed and mixture (older cars) and the O2 sensor.
Auto Tune Ups, Body Services & More in Dallas, Texas (Just Minutes Away from Addison, Balch Springs, Carrollton, Cedar Hill, Coppell, DeSoto, Duncanville, Farmers Branch, Ferris, Garland, Grand Prairie, Grapevine, Irving, Lancaster, Lewisville, Mesquite, Ovilla, Richardson, Rowlett, Sachse, Seagoville, Sunnyvale & Wylie, TX)
You may start looking at a tune up at about 60,000 miles, check your owner’s manual. Top Notch Body Shop & Mechanic can handle all your auto body needs.