Hello from North Carolina,

My 03 Wrangler has had what I would call a lifter tick for a couple of years now. Once the engine warms up, the tick smooths out and is hardly noticed. In the last week I've noticed a loud tick, and occasionally it feels like its only hitting on 5 Cyl's. I accelerate a little and the 6th cyl comes back and it smooths out again.

My TJ has 138,000.

I've done some research, and I've read that it could be an exhaust header crack, bad lifter, bad injector, and even a bad piston. Also the oil is full but due to get changed, which i'll do in the next week.

I'm thinking more towards the injector theory...Any advise please?