The issue is not really the Timing belt cracking and failing. A guy in my neighborhood bought a 98LC off the lot in 1998. He didn't know it needed a timing belt at 90K or heater tee's. Last year at 250k miles and ~20 years, He had them done at a shop somewhere, shop offered no remarkable comments.
I've heard stories in mud of T-Belt failure causing interference damage. But "I've not seen" one picture of bent valves form interference or damaged pistons posted.
I've read many stores of broken belt under load, accelerating on HWY or spinning crank with belt off without interfance. In which new belt installed and all was good.
We've long held a belief that the
2UZ-fe VVT-i engine is a true interference engine. But I pulled the belt off a VVT and turned the crank 720 degs and then some,
No interface. I pulled the heads, not a single mark on pistons tops or valves. That said, a service manager at a Toyota Dealership said to me; they bought a client a new engine after a Tech aligned the belt to the wrong (T) marks.
I suppose a very high mileage engine with weak valve springs in a really loose engine could possible allow for some interference in the right condition, just I've not seen it.
What I've been seeing is water pumps weeping (failing), bearings of pulleys a bit noisy (failure) and tensioners leaking (failing).
Additionally some gasket begin failing (for one reason or another) need refreshing to protect metal components, like block from damaging effects of electrolysis.
It's a good time to inspect the fan bracket. Any play, noise or oil seepage and replace for sure, if not just replacing as PM.
I've never seen a bad belt other than in mud.
