Here's what could be wrong:
* Bent valves: This is the most likely and potentially most costly damage. Bent valves need to be replaced or repaired, requiring head removal and potentially machine work.
* Damaged pistons: Less common, but possible. A severely bent valve could puncture a piston. This is very expensive to fix.
* Damaged cylinder head: The impact could crack the cylinder head. This requires replacement or extensive repair.
* Damaged crankshaft: Less likely, but a possibility depending on the severity of the piston-valve collision.
* Timing belt components: The tensioner, idler pulleys, and water pump might also be damaged and need replacing.
Is it worth fixing?
This depends on several factors:
* The extent of the damage: A few bent valves are significantly cheaper to fix than a cracked head or damaged pistons. You *must* have a mechanic inspect the engine before deciding anything. Getting a compression test is crucial to assess the damage to the cylinders.
* The car's overall condition: Is the rest of the car in good shape? If the body is rusty or the other systems are failing, investing heavily in engine repair might not be worthwhile.
* The cost of repair versus replacement: Get quotes for repair from a reputable mechanic *after* they've assessed the damage. Compare this to the cost of a used engine or a rebuilt long block (the engine without the peripherals). Used engines are a gamble as you don't know their condition.
* Your mechanical skills and tools: If you're mechanically inclined and have the tools, you might save some labor costs, but even then, specialized tools might be needed for valve repair.
In short: Do NOT start the car. Tow it to a reputable mechanic specializing in older vehicles. Have them perform a thorough inspection, compression test, and provide you with a detailed estimate of the repairs *before* you decide on a course of action. The cost of repair could easily exceed the value of the car, especially if significant internal damage is present. Weigh the repair costs against the cost of finding a replacement engine or a different car altogether.
