Getting in this thread a bit late. I've never ever had a timing belt or chain go bad on me in any way until now. My 2002 Avalanche 5.3 L 4x4 Z71 1500 has about 150K miles with zero problems and a change of plugs by me for the [censored] of it at 135k. No change in performance or mpg.
Meantime, I'm about to go over 100K miles on my 2013 Lincoln MKT 3.5L ecoboost and I had the nefarious P0016 Bank 1 Crankshaft Camshaft Sensor A reading after the check engine light would come on for days then go off for days than back on. I was going to replace the sensor but thought better of it since the check engine light didn't stay on. Then there was a few days when the check engine light didn't come on at startup. I took it to Lincoln who informed me that the main timing chain had stretched, which surprised me with Lincoln having done all the maintenance since I bought it new in 2013. They recommended that I replace the water pump because it would save me bucks in the long run....cost $2400. I just did the 100K maintenance 3 weeks ago except for the plugs.
Frankly, I am unsure of that diagnosis since I have zero symptoms in performance or sound or efficiency. I was going to buy the 2019 Ford F150 with a similar engine. Now, I wouldn't touch it. Great technology with parts not up to the task, IMO. Transverse engine 4 valves per cylinder, 4 camshafts, and 4 camshaft sensors. It also has 3 chains, the center chain I'm told is the problem with no assurance that it won't go out again in another 100K miles. After leaving the shop without the repairs and down $150 and 3 hours, no engine light and the engine running well as best I can determine.
Looks like I'll be looking at a Silverado or other Chevy/GMC pick up.
