Skip the auto shop - Our mechanics make house calls

Bent Valves and Other Common Issues After a Timing Belt Snaps

timing belt

Ignoring your timing belt can come with a high cost. Timing belts don’t often snap, but when they do, it can cause piston damage, ruined cylinder heads, and engine valve damage.

Probably, when you think of your engine, you picture the valves and pistons, but you don’t think much about what keeps them in good working order. Let’s state it plainly – nothing is more important than the timing belt. It drives the camshaft, which is what keeps the valves synchronized, and the crankshaft, which controls the pistons. Your timing belt tells the pistons when to rise and fall, and the valves when to open and close.

How to tell if your timing belt is bad

Timing belts don’t often give you a lot of warning when they’re about to give way – they might squeak or chirp, or they might just suddenly break. More often, though, damage is due to wear in the timing belt. You can do a visual check – see if there’s any cracking, glazing, missing teeth or oil contamination. Or you can have a mechanic check the belt for you. Most vehicle manufacturers also recommend that you make timing belt replacement a part of your routine maintenance, replacing it every 60,000 miles. Some belts are good for up to 100,000 miles. If you’re in doubt, check your owner’s manual, or ask your dealer or mechanic.

Interference vs. non-interference engines

The level of damage caused by a broken timing belt can depend on the type of engine you have in your car. A non-interference engine provides clearance between the valves and pistons, so if the timing belt breaks, you might end up with bent valves, and you might have to have your cylinder heads rebuilt, but the engine isn’t likely to be destroyed.

With an interference engine, though (and about 70% of the vehicles on the road today have this type of engine), the pistons and the valves move within the cylinder – just not at the same time. The pistons and the valves “own” the cylinder at different times. Here’s the thing, though – the period of time between “ownership” can be less than a second. If the timing is off, be it less than a second, there is nothing to stop the pistons and cylinders from colliding. This throws the rods off, and they start to poke holes in the engine block. Eventually, the engine simply cracks in half, and there’s no way to repair it.

Now you know the disastrous consequences of neglecting your timing belt – engine valve and piston damage, bent valves, cylinder heads that need to be rebuilt or replaced, and possibly even total engine destruction. If you don’t want to see those dollar signs adding up, check your timing belt regularly, and have your mechanic replace it on schedule.

The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
Icon-warranty_badge-02

Skip the repair shop, our top-rated mechanics come to you.

At your home or office

Choose from 600+ repair, maintenance & diagnostic services. Our top-rated mechanics bring all parts & tools to your location.

Fair & transparent pricing

See labor & parts costs upfront, so you can book with confidence.

12-month, 12,000-mile warranty

Our services are backed by a 12-month, 12,000-mile warranty for your peace of mind.

Get A Quote

Need Help With Your Car?

Our certified mobile mechanics make house calls in over 2,000 U.S. cities. Fast, free online quotes for your car repair.

GET A QUOTE

More related articles

P0222 OBD-II Trouble Code: Throttle/Pedal Position Switch/Sensor B Circuit Low Input
P0222 code definition Throttle/Pedal Position Switch/Sensor B Circuit Low Input What the P0222 code means The manufacturer specifies a range of acceptable voltage to be produced from the throttle position...
Veteran and Military Driver Laws and Benefits in New Mexico
The state of New Mexico offers a number of benefits and perks for those Americans who have either served in an Armed Forces branch...
P2159 OBD-II Trouble Code: Vehicle Speed Sensor B Range/Performance
Diagnostic Trouble Code (DTC): P2159 P2159 code definition Vehicle Speed Sensor B Range/Performance Related Trouble Codes: P2158: Vehicle Speed Sensor B P2160: Vehicle Speed Sensor B Circuit Low P2161:...


Related questions

Q: Unable to shift power steering motor to replace fan belt. Have loosened x 2 adjuster bolts.

Hello. It's been a while since working on one of these, but if my memory serves me, there is either a bolt that is sort of behind and under the pulley, accessible with a box or open-end wrench. The other...

Q: Car won't start after doing valve cover job.

Hi there. From the description you have provided, something was reassembled incorrectly. Not replacing the upper intake (plenum) gaskets should not have caused the vehicle's no start condition. Once that you have the plenum removed, carefully inspect all the components...

Q: Gas pedal pressed to floor before car accelerates

Hello, we will be happy to assist you. I would suggest that you have a technician use a capable scan tool to perform a function test on the vehicle. Doing so will test most of the sensors on the vehicle...