I have a '99 F150 with the 4.2l v6. The engine is backfiring on one cylinder. It doesn't happen much & no one else has noticed it while riding with me, but I know it's there. Has anyone else had this problem? Did you fix it or was it a dealership type of repair? Any help would be cool.

 

What do you mean it backfires on one cylinder? Do you have dual pipes and it pops on draw back, that would be normal, I love it. It could be backfiring if it is out of time.

 

i had this problem until i changed my plugs. I filled up with supreme, and had around 22,000km on the plugs.

 

What I mean is when I'm shifting from 2nd to 3rd on the left bank of cylinders I can hear a muffled "pop" sound. It usually happens when the humidity is high or it's raining. Also, I detect a little surging under hard accelleration. The truck only has a little over 40K on the odometer, but I've noticed this since it had 17K. I haven't checked anything because it's still under warranty & I keep telling myself I'll get it by the dealership. But the dealership is anbout 60 mi. away.

 

I'm going to guess it is spark plugs and/or wires. There could be a small worn spot on a plug wire and the moisture as you said is getting to it. Be sure and let us know when you find out what the problem is.

 

Thanks