If it is the 6VE1 engine like we have, 112000 miles = 180000km, so it could be a valve clearance issue.
I have seen valve clearances get larger from front to back generally from poor service history.
The valve clearance is shim over bucket and special tools are required.
You can do it the long winded way measuring all the clearances, remove all the cams, remove all the shims, mic them up, do some maths for required shim thicknesses, reassemble cams, remeasure all clearances again.
A big job, done it twice now.
I've also replaced a crankshaft from bigend bearing failure, starved for oil.
If you do think the noise is abnormal, I'd get another local opinion, or look at another car.
Can be expensive to do, the shims alone are about $20 each.
Hope this helps.