* No Start: This is the most obvious sign. If the engine cranks but doesn't fire, a jumped timing chain is a high probability.
* Loud Knocking or Rattling Noise: When the valves and pistons are out of sync, they can collide, resulting in a very distinctive and often severe knocking or rattling sound. This is a serious issue and should be addressed immediately to prevent engine damage.
* Rough Running or Misfire: If the timing is slightly off, the engine might run roughly, stumble, misfire, or lack power. This is less definitive than a complete no-start or loud knocking.
* Check Engine Light (CEL): The CEL will almost certainly illuminate, usually with codes related to misfires or crankshaft/camshaft position sensor problems. However, the CEL alone isn't diagnostic of a jumped timing chain – other issues can also trigger it.
* Exhaust Smoke: Excessive smoke, particularly white (coolant) or blue (oil), can indicate internal damage caused by a jumped timing chain. This usually appears after some running time after the timing event.
Important Considerations:
* Interference Engine: The 2.2L Chevy is an *interference* engine. This means that if the timing jumps, the pistons and valves can collide, causing serious and potentially catastrophic damage. Immediate action is critical.
* Distinguishing from other problems: Many other issues can cause similar symptoms (bad ignition system, fuel delivery problems, etc.). A proper diagnosis requires mechanical knowledge or a qualified mechanic. Don't assume it's a jumped timing chain without a thorough check.
* Inspection: Visual inspection might reveal a broken timing belt (if belt driven) or significant slack in a timing chain. This requires removing the timing cover which is a moderately involved repair. A mechanic will have the tools and experience to perform this check safely.
In short: If your 2.2L Chevy engine isn't running right, especially if accompanied by a loud knocking sound, immediately stop driving it and have it towed to a mechanic for diagnosis. Driving with a jumped timing chain will likely cause significant and expensive engine damage.
