View Full Version : Question in regards to timing belt (Toyota)
Do timing belts usually show symptons before they go, or is it something that just goes and you're screwed?
I need to replace the timing belts on both of my Toyota trucks (and plan on doing so), but I was just asking anyways.
Sometimes you get a sqeak or a squeel but most of the time they just go.
Give us year/model/motor size on the trucks.
The belt its self will almost never make noise. Over time the belt will develop small cracks as it becomes more brittle with time. Just like the belts running your A/C and power steering. Eventually it snaps, and if it's running, the pistons hit (read: bend) a couple of valves, locking the motor up, and requiring serious money spent on repairing/replacing the head.
The noise you'll hear if it IS making a noise are usually from the bearings in the idler pulley or tensioner pulley wearing out. A whirring, squealing, or grinding/howling noise is typical. Sometimes the timing cover will rub on a pulley or the belt, and you'll get a noise that way. On most vehicles with plastic timing covers this is easy to diagnose by simply pulling the top of the cover back, and checking to see if the noise gets louder.
If not, you need to take the serpentine belt off the motor and run it again without the alternator, power steering, and other accessories turning to better diagnose the noise.
Earlier Toyota trucks with the 2.4L 22RE 4 cylinder had a chain that was run around plastic guides. When the guides wore through, the chain would begin to rub against (and eventually through) the aluminum timing cover. Often times, this resulted in a coolant leak as well. Lots of people have unnessicarily replaced the head or head gasket because of this leak. You'll usually hear a 'rattle' noise when starting the truck if this is happening, which quickly goes away.
Oh, and many newer japanese motors have a water pump up under the timing cover, running on that belt... instead of out in the open like older engines. It's always a good idea to replace it while you're in there.
The timing belt it's self is fairly cheap. Usually around $20-70. It's the water pump, tensioner/idler pulleys, and several hours of labor that kill your bank account.
I did the timing belt on my wifes wind-up toy (geo metro) for $90 total in my garage. But since it requires unbolting and dropping the engine 6 inches out of the car to remove the crank pulley, that's not a job for everyone. There's also the "put it together wrong and you get to buy a new motor" factor. ;)
Yeah, they usually give a symptom, a mileage time when to replace it, and you better follow the advise, especially on a Toyota, that is an intrusion engine.
I had a '97 prelude that had the timing belt go at 59,400 miles (600 shy of the recommended replacement mileage). As stated, it's an inclusion engine so if the belt breaks it sends the valves into the piston. It cost me a LOT more money (about $1500 bucks, but i did get a better head). I would't wait.
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