I've recently noticed a tick from my engine. I doubt it's a bad lifter, I had them replaced last year. I was possibly thinking an exhaust leak. One thing I was wondering though, is it possible old or fouled plugs could cause a tick? It's been about a year since my last tune up and the car runs rich, so the plugs may be tired. I'm kinda hoping it's just a tune up thing. Any replies will help.