What is the clicking sound coming from my motor? on 2005 Pontiac Grand Prix

Could it be related to the studdering while accelerating - like a constant hickup until I either let off the gas or push it to the floor? I have been adding Lucus Fuel Injector cleaner which stopped the hickuping with the RPM's the first day but then it has stayed constant while still using the cleaner for the last month at every gas fill up. But lately the clicking has started. I just added Seafoam to the motor 2 days ago and the clicking stopped for a day but is starting to come back faintly sounding. I drive a ton of highway driving daily...usually 700 miles a week. Car has 240k miles all on original motor. Plugged computer into car and it just says "Evap leak large" which is what it has said for the last 4 years - we can't seem to find the problem. Could it be related to this? Help haha - I'm trying to hit 300k in my GP!

by in Somerset, WI on October 16, 2013
2 answers
ANSWER by on October 16, 2013
Not good to use injector cleaner on every tank of gas. Adding oil additive and it quit for a day, Huh Sounds like you need to get out of it for a day and let someone diagnose the noise before you get stuck out on the road.
ANSWER by on October 16, 2013
I agree with #1, it is getting old & tired, probably time to start looking for another ride! Good idea to have a mechanic put an ear to it though.