Chevy Silverado Starting Problemsby Paul Novak
Few things are as annoying as turning the key in your truck and finding it will not start. There are many problems that can result in a Chevy Silverado's failure to start, making diagnosing the trouble even more frustrating. Depending upon how the failure occurs, you can check for several basic problems before making the decision to call a mechanic for assistance.
Engine Won't Turn Over
Not turning over is usually a result of the starting system failing to get the required electrical power needed to turn the starter. When you turn the key and get no result at all from the engine, it is commonly due to bad battery connections or a discharged battery. Less common problems are a break in the starter circuit's wiring, a faulty starter or a faulty solenoid. Before suspecting electrical or mechanical failures, however, ensure that the parking lever is in park and that electrical connections are clean and secure.
Engine Turns But Won't Start
If the engine turns over but will not start, this usually means that either the engine is not producing a spark at the sparkplugs or fuel is not being delivered to the engine. Common causes for no spark are a weak battery, indicated by a slow-turning starter, a faulty ignition coil or a wet ignition system. Less common problems are faulty sparkplugs, broken or disconnected coil wires or broken wires in the ignition system. A fuel delivery problem is usually caused by a clogged fuel filter, no fuel in the tank or a faulty fuel pump.
Starter Turns Without Turning the Engine
A starter that spins without turning the engine is caused by the starter gear failing to engage the engine's flywheel. This usually indicates that the starter pinion is sticking and not allowing its gear to move into position with the flywheel. Less common are broken starter gears or broken gear teeth on the flywheel resulting in the starter being unable to contact the flywheel.
Engine Hard to Start Cold
An engine that's hard to start when it is cold is caused by the engine either producing a weak spark or not providing enough fuel to the cylinders. A weak battery will produce a weak spark at the plugs, and will turn the engine over slowly. A worn distributor cap, old or broken plug wires or a worn distributor rotor can result in a weak spark at the sparkplugs, causing the engine to turn over excessively before catching. A clogged fuel filter, dirty fuel injectors or weak fuel pump can result in too little fuel reaching the cylinder, causing poor fuel ignition and the need to depress the accelerator to assist starting.
Engine Hard to Start Hot
An engine that is difficult to start when hot can be caused by a clogged air filter restricting airflow to the intake. This causes a rich condition at hot startup, often noticed by "flooding," or the smell of gasoline after repeated starting attempts. Another possible cause is a weak coil or electrical system that is compounded by the heat produced from a hot engine. Heat increases resistance in electrical systems, lowering the effective voltage at the critical ignition components. Less common problems include faulty emissions systems that must be diagnosed by checking for fault codes stored in the vehicle's computer with a scanning tool.
- Hayned Repair Manual: Chevrolet Silverado-GMC Sierra; 1999 thru 2006
- AllPar: What to do when your fuel-injected and carbureted car won't start
- 4 wheel drive image by Canakris from Fotolia.com