I have a sound coming from the engine sounds like throwing water on a hot piece of metal. Spitting type of sound. It first appeared after I had a shifting point changed and had the truck on the dyno. Not the tranny, and the speed shop can't seem to find out this what or why this sound appears. It just comes and goes. It's driving me nuts.

 

Sounds like your Air Conditioning condensate water dripping on the exhaust pipe - which my truck does all the time after running since I had the service bulletin work done on the drain. But, it seems your mechanic would have suspected that?

 

WE turned off all the air systems, plus anything else. We can't hear it in neutral, only when we're driving and at any speed from 20-90mph. I parked the truck last year for two months, then this spring it was still there. Drove it up to the tranny shop, they said it was coming from the front of the motor.

 

Did you check the spark plugs, the heater hoses, and the intercooler hoses for leaks?
Exhaust leak?

 

I changed plugs and belt, with the regular maintenance. They looked over the motor and they said without ripping the motor apart it's a grab bag of guesses. I thought it was a vacuum leak, but it comes and goes. There will be nothing for 200mph, then it'll do it for a few days. Drive it like easy,or beat on it, it seems not to matter. Thought another Lightning owner may of come accross this problem. Would a vacuum or some kind of pressure switch come and go with a glitch?