| Hard Starting: This is the most common form of | | | | other engine deficiencies. Does it stall when hot? |
| car trouble. It's usually due to some unperformed | | | | Cold? With air conditioning on? To make diagnosis |
| maintenance. If the starter cranks the engine, the | | | | easier, make note of when it happens and advise |
| electrical system is probably okay. The culprit | | | | your technician. |
| could be a starting sensor (on fuel injected | | | | Power Loss: How long since the fuel filter was |
| models) or the choke mechanism (on engines with | | | | changed? A dirty filter is a common cause of |
| carburetors). Frequently, starting failure can be | | | | power loss. As noted under "poor gas mileage", |
| traced to an electronic component or a computer | | | | there can be many causes of this condition, most |
| controlling the ignition system. | | | | of which can be located with a diagnostic |
| Knocking: The noise generally is heard when the | | | | procedure. |
| engine is under load, such as when accelerating or | | | | Poor Gas Mileage: By keeping a regular check of |
| climbing a hill. While it often may be caused by a | | | | gas mileage (miles driven divided by gallons used); |
| thankful of interior gas, ignition knock frequently is | | | | you can tell if your engine is losing efficiency. |
| a sign your engine needs attention. It also can be | | | | Increased gas consumption may be accompanied |
| caused by a buildup of carbon inside the engine. | | | | by other symptoms listed in this section. Note |
| Lake-model cars are equipped with a knock | | | | that poor gas mileage also may be due to: under |
| sensor which 'hears' the sound and makes | | | | inflated tires, engine running too cold, transmission |
| corrective adjustments. But it cannot compensate | | | | malfunction, dragging brakes, misaligned wheels. |
| for a severe malfunction, a condition that can | | | | Dieseling: This also is known as "after-run". The |
| affect engine performance and even damage the | | | | engine keeps chugging and coughing for several |
| engine. | | | | seconds after the ignition is shut off. Causes can |
| Stalling: This can be caused by incorrect speed | | | | range from inferior gas to excessive idle speed. |
| adjustments, a malfunctioning sensor or switch, | | | | Carbon in the combustion chamber also may |
| dirty fuel-system parts, worn spark plugs, or | | | | cause dieseling. |