Skip the auto shop - Our mechanics make house calls

Q: Car damage after timing belt replaced

asked by on

I just replaced the timing belt, but I think there is valve and piston damage.

A: Your Subaru Forester comes equipped with a ...

Your Subaru Forester comes equipped with a boxer engine that is often referred to as an interference engine. An interference engine means that the pistons and valves inside occupy the same space but at different times during operation. The timing belt is what keeps these components from colliding together. When the timing belt fails, it is then likely that the pistons and valves occupied that same space and caused damage.

In most cases the pistons can be reused and bent valves can be replaced. However, I have seen when the force of the two colliding can actually crack the pistons. Cracked pistons would be a worst case scenario, requiring a full engine rebuild to repair. Bent valves means the cylinder heads will have to come off so the repair can be performed. Once the cylinder heads are off the pistons can be carefully inspected for damage. A certified mechanic will have the proper tools to determine if you have one or more bent valves, or if your pistons are cracked.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Save up to 30%

Get a quote

What others are asking

Q: Air conditioner compressor does not turn on

Hi. If the air conditioner compressor does not turn on, this may perhaps be indicative of a problem with the fuse or relay, or perhaps something more serious, such as a failed compressor. I would recommend having the vehicle's air...

Q: The car cranks but occasionally wouldn't start

If the battery is going dead after a couple of days then you have an issue with something drawing the battery down. A battery that is low may not be able to start the engine since the starter will take...

Q: Unable to lock hatchback door

You likely have a bad door lock actuator, or a broken wire. To determine the cause of the problem, the hatchback door panel will have to be removed, then electrical testing will have to be performed. A qualified technician from...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.