“Do I Need a Tune-Up?” – Clearwater Automotive Repair Feature Article
Do I need a tune-up? Simply, yes! It saves you money, aggravation and time.
It’s been a couple of years since you had the car tuned up but it still seems to be running fine. Leave well enough alone, right? WRONG!
On most vehicles today, malfunctions may be camouflaged by computers whose function is to keep the engine running as efficiently as possible as long as possible. When they no longer can compensate for mechanical discrepancies, they may just fail. The vehicle is disabled. Periodic diagnostic checks and maintenance ran prevent this sometimes disastrous situation.
Symptoms of engine trouble on most vehicles today are subtle. It’s not easy to tell if your car needs a tune-up because the symptoms are masked by com- puterized controls. Preventive diagnosis, done periodically, can keep your vehicle running trouble-free for years. Short of that, if you do detect a change in your vehicle’s performance, make a note of it and report it to your technician for further diagnosis and corrective measures.
1) Car Is Hard Starting
This is the most common form of car trouble. It’s usually due to some unperformed maintenance.
If the starter cranks the engine, the electrical system probably is ok. The culprit could be a starting sensor (on fuel injected models) or the choke mech- anism (on engines with carburetors). Frequently, starting failure can be traced to an electronic component or a computer controlling the ignition system.
2) Car Is Knocking
This noise generally is heard when the engine is under load, such as when accelerating or climbing a hill. While it often may be caused by a tankful of inferior gas, ignition knock frequently is a sign your engine needs attention. It also can be caused by a build-up of carbon inside the engine.
Late model cars are equipped with a knock sensor which “hears” the sound and makes corrective adjustments. But it cannot compensate for a severe mal- function, a condition which can affect engine performance, even damage the engine.
3) Car Has Power Loss
How long since the fuel filter was changed? A dirty filter is a common cause of power loss. As noted under “poor gas mileage”, there can be many causes of this condition, most of which can be located with a diagnostic procedure.
4) Poor Gas Mileage
By keeping a regular check ot gas mileage (miles driven divided by gallons used) you can tell if your engine is losing efficiency. Increased gas consumption may be accompanied by other symptoms listed in this pamphlet.
Poor gas mileage also may be due to:
• Underinflated tires
• Engine running too cold
• Transmission malfunction
• Dragging brakes
• Misaligned wheels
5) Car Is Stalling
This can be caused by incorrect idle speed adjustments, a malfunctioning sensor or switch, dirty fuel system parts, worn spark plugs or other engine deficiencies.
Does it stall when:
• With air conditioning on?
To make diagnosis easier, make note of when it happens and advise your technician.
6) Car Is Diesling
This also is known as “after-run” The engine keeps chugging and coughing for several seconds or more after the ignition is shut off. Causes can range from inferior gas to excessive idle speed.
Carbon in the combustion chamber also may cause dieseling.
7) Car Has an Exhaust Odor
The smell of rotten eggs comes from the catalytic converter, part of your car’s emissions control system. The odor can be due to an engine problem or it can be a sign your car’s catalytic converter is malfunctioning.
8) Car is Rough Idling
A malfunction in either the fuel or ignition system can cause an engine to run rough. It also can be due to an internal engine condition, such as a bad valve or piston.
Does it occur when idling? When accelerating? At all speeds? Your best bet: Have a qualified technician perform diagnostic and tune-up services as needed.