My timing belt broke on my car while I was driving it and now the engine won’t start. I was told by my mechanic that the valves are bent? How can the valves bend, is he lying to me? What should I do now?
Elena, NY
Hey Elena,
Yes the valves can bend when the timing belt breaks, and this can be very costly to repair. When the timing belt breaks while the engine is running the valves can come in contact with the tops of the pistons and when this happens something has to give and usually the valves take the brunt of the blow and bend. Once the valve is bent the engine usually will not re-start or if it does it will run poorly and smoke out the exhaust pipe.
Removing the cylinder head (basically the top half of the engine) and replacing the valves is your cheapest option, replacing the engine is the most expensive option. In most cases replacing the valves, commonly referred to as a valve job, will correct the damage. I have in a rare case seen the piston crack, and in that case replacing the complete engine was the only real option.
I would suspect a valve job to start at about $1,000 depending on your vehicle. This is a large job and there are many other items that you might want to consider replacing at this time since the mechanic will have to remove them to perform the valve job. Some of these items would be:
1. Spark plugs and spark plug wires
2. Timing belt tensioner pulley
3. Water pump
4. Thermostat
5. Fan belts
6. Heater and radiator hoses
I would also recommend you have an oil change done and install new antifreeze in the radiator after this repair. Dirt and debris will fall from the cylinder head once removed and can contaminate the engine oil and antifreeze.
Here is a picture of a bent valve, notice the bent towards the bottom of my palm at the dark area of the valve. Incidentally the dark area of the valve is caused by cheap low grade gasoline which leaves carbon deposits on the valve…just like you hear about on the TV commercials.
Blessings,
Austin Davis