Our crunching sound on bumps was front anti-roll bar bushings (MZ5 2006 15k miles). It did it in cold & wet weather (Seattle winter rain, 30s-40s deg F) and was really loud. Fixed by Everett (WA) Mazda several months ago, complete success so far.
We have 2000 rpm hesitation once in a while...
Very similar here. It's very occasional, like I have to hit just one spot of combination of engine rpm and throttle opening. I believe it's about 50% open throttle at about 2000 rpm. When it happens, it is a complete failure of power for a split second. The passengers' head lurch forward and...
A different thought here, that I never would have applied to any of my previous cars (VW / Honda / Nissan). My Mazda5's dipstick seems to be somehow "oil repellent". When I first pull it out, it looks like it has no oil on it. The solution is, stick it back down all the way and pull it out...