If the Idler bearing seizes or tensioner goes bad the belt will break or fall off. Those should be replace with the new belt.
Timing chains and gears can give an audible warning prior to failure that something needs attention. There are those with a tin ear who will not hear this warning. I have not heard of a timing belt giving a fair warning before failure.
2001 Hundyi Excel At 70,000 miles in a parking lot. One lifter was damaged. All under warrenty {75,000}.
When I am in the States, I reside in a retirement park near the border. A neighbor told me a couple years ago, that he was a retired mechanic, and that he could tell by the sound when his timing belt on his Toyota needed replacing. He usually ran them around 140,000 or more before that happened.
I cannot vouch for his statements. In this world anything is possible.
My timing belt didn’t break, but I did have two serpentine belts and a tensioner pulley break on my 1998 Ford Ranger. Not a fun experience! Also had two ignition switches lock up, requiring that my truck be flatbedded to the garage. My mechanic tells me this is a common problem with Fords. The stupid thing is made out of plastic. How stupid is that?
Timing chains and gears can give an audible warning prior to failure that something needs attention.
Operative word there is CAN…Not true in ALL cases. I had a chain slip…I did hear a noise…just before it slipped…about 2 seconds before it slipped…Luckily it WASN’T an interference engine.
Amen. All my cars, except my 1995 4-Runner, have timing chain. I was still an in-experience DIY when I bought the 4-R. I have peace of mind & save a bundle.
Timing chain play or backlash can be measured and there’s a spec for whether or not you should replace the chain and gears at that point. No such procedure exists for belts, especially if you have a spring loaded tensioner. Plus so many belts are on interference engines. All-steel chains and gears last much longer than belts. What is the rationale, from the carmaker’s point of view, for belts? It’s gotta be more than “Chains are noisier.”
I bought an '82 Chevette from the original owner in 2000. The timing belt broke at two o’clock in the morning thirty miles from home cruising up a deserted highway–no kidding–maybe nine months after I bought it. It then broke every three and a half to four months after that because my ‘mechanic’ told me there was an oil leak over the timing belt and that it would be easier to replace the timing belt periodically than to fix the oil leak.
P.S. I never left the house without a quart of oil or an extra timing belt after that.
1987 Toyota Tercel, 123000 miles. I was cruising at 65 and began slowing down as I approached a stop light. As I stopped at the light, my car died. It took us forever to discover that it was the timing belt that had broke. No valve damage, still cost a fortune to fix though.
95 Neon, broke in 2006 at around 100,000. don’t know exact mileage due to intermitent odo/speedo operation. On a flat highway at 60 mph in nice weather. Tensioner bearings failed and belt broke. Replaced tensioner, belt, and 16 bent valves. Still runs great
Helping a friend whose Ford/Mitsubishi pickup truck had quit. I found that there was no spark and suspected a bad ignitor or coil. Later that night I realized that every time I took off the distributor cap the rotor was in the same position (We had always put the cap back on before cranking the engine). The next morning I verified that the cam was not turning and that the belt had broken. The timing belt had been changed fairly recently (maybe a year) but there was a leaking oil seal on the front of the engine, contaminating the belt.
This happened to me with two used cars: a 1983 Honda Prelude and a 1985 Nissan Sentra. With the former, the belt broke on an Interstate-type road at 60mph as I was entering an exit ramp. Because of the engine, I only had to replace the belt ($200). With the Sentra, the belt broke at 5mph as I was stopping at a stop sign. However, because of that engine configuration, I had to have the entire engine rebuilt. I will NEVER do that again; nothing but problems afterwards. If you own a vehicle with a timing belt and the service manual recommends replacing it at x-miles; DO IT.