Originally Posted by MDH33
Yeah, not sure why they checked the compression either, which made me suspicious. I told him to call back and confirm they checked the timing belt. I also said it might be worth taking it to another shop. (He's in Michigan).
Would the timing belt failing or slipping cause a compression issue?
Yes. If the cam timing is wrong the valves are opening at the wrong time in the cycle and yields low or zero compression. Not sure checking the compression is any easier than just inspecting the timing belt on a 5VZ, but it's a valid check for a slipped belt or chain. If the mechanic works on lots of brands he may not be super familiar with the 5VZ, though, and sometimes a compression check is actually easier. If it broke the engine wouldn't run at all, I'd guess Isaac is probably right about the tensioner if all that was done was a belt and maybe water pump.