Check the engine mounting bolts for tightnessI inherited an MTD TurfPower 42" lawn tractor with about a 12 h.p. Briggs engine. I try to keep it running in memor of my dad. It uses a little oil and had been running o.k., but now when I shut it off, it makes a clanging sound and it wheezes when it stops. I'm guessing it could be something with the valves. Any ideas?