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When a Timing Belt Breaks?

I have an '03 Honda Civic EX and an '01 Toyota Sequoia both of which have Timing Belts. The Honda is due to replace at 100K miles in a couple of years and the Toyota is due now at 90K miles. So, what happens in these cars if the belt breaks? I know in some cars the valves are damaged because they hit into the pistons, and on other cars the motor stops and won’t run but the pistons and valves do not contact each other. How do you know what type of motor you have? This is not covered in the owner’s manual.

I like to use the Gates Timing belt resource. Do a quick search on Gates Timing Belts, and you will get the on line catalog. It includes annotations of interference engines when applicable, plus more info. Interference engines are the ones that will ruin valves when the belt breaks.

You sure it’s NOT listed?? Every vehicle I’ve owned that had a timing belt stated explicitly if it was an interference engine.

Thanks, according to the Gates site both are interference type engines. Guess I’d better not wait too long to replace the belt in the Sequoia!

I’m one of those “people” who read the manual cover to cover and I don’t recall seeing the term interference type motor. They likely say something about possible damage but that could mean anything, such as loss of control due to the motor stopping suddenly. I’ll reread them again someday. Thanks

Get the best manual you can afford for your car,read it every chance you get. Get to know those engines inside out ,at least from the manuals perspective. Is’s so nice to see a Service Advisor turn tail when confronted with a informed customer,don’t let them take advantage of you not being “in the business”.When you hear B.S. let them know it is just that.

Stay connected to this Forum and it will help you greatly,most advice/insight given here is very good.

While the job can be expensive, it’s not something you want to postpone. You’re smart to get it done when recommended in the owner’s manual.

most of the Honda’s are interference type engines and the POSSIBILITY exists that valves can be hit, but this occurs less often in automatics than manual trannies. A manual will continue to drive the pistons unless you are pretty quick with the clutch, but I have seen autos that don’t damage the engine even tho they are “interference engines”. Depends on your speed etc…

Sell the Sequoia immediately (V8) if the engine is still running. I thought that is what I have heard. Maybe not, after checking CR.

That doesn’t make any sense. I can’t believe that a fluid coupling (torque converter) allows the rotating engine parts to gently and quickly come to a stop as the pistons contact the valves. The crankshaft and pistons have enough momentum that the pistons are going to whack the valves pretty hard, no matter how much the torque converter slips or how quick you are on the clutch pedal. In other words, don’t count on having an automatic saving your bacon on an interference engine when the timing belt breaks.

I’ve seen broken interference engine belts on autos and sometimes they don’t damage the valves or pistons, as noted, it depends on the conditions, engine speed, condition of tranny hydraulics, etc…no guarantee obviously, but not a 100% certainty of catastrophic failure…those with stick invariably have problems. Honda made extensive use of cam profile mods using oil pressure to increase power, and mileage and VVT timing engines VTEC is also a factor. But why take a chance, change when recommended and ONLY USE FACTORY TIMING BELTS for HONDAS, they cost about double a Gates or aftermarket belt but use different material and construction. I have had many Acuras and always changed the belts and when removed they look new and undamaged or worn, but then I alway changed the tensioner (which some try to save some money on)/ I microscopically examined the belts and found them to show no evidence of oxidation, slippage or micro fractures. But who cares, I paid an independent to do the work each time and saved at least $300 each time. Cheap insurance.

My '03 Civic EX is a stick and I will change the belt as per mfg specs. Thanks for the info about the source for the belts and quality issues with aftermarket parts.

The Sequoia runs great, haven’t read the CU reports but other sites all say they are reliable. Will get the belt job done in the next few weeks. Plan is to keep this SUV for a long time, need it to tow trailers.

Consumer Reports reliability data shows brakes and air conditioning as higher than average repair issues, and nothing else. Engine, major and minor, are all high rated as their best reliability rating.