My 06 5.4 SCAB has been making a weird noise for the past few weeks. I would describe it as somewhere between a nock and a ping. I can't pinpoint exactly where it's coming from, and it seems to happen randomly (AC on or off, heater on or off, hot or cold, any RPM, moving or not). It happens probably five or six times a day.

The truck is running perfectly, like it always has. I havent noticed anything else weird going on. Where should I start my investigation? Am I over reacting?

 

If its a noticeable tapping sound coming from the front of your engine at low RPM when the engine is at running temperature, it could be your cam phasers. There is also issues with lash adjusters on the 3V 5.4. Look at TSB 06-19-8

 

Also check the belt pulleys and belt tensioner by removing the serpentine belt or by using a mechanics stethescope and while your at it check the cat heat shields. A stethescope is very helpful for finding noises of any kind. Good luck.

 

I just read the TSB. I don't think any of that applies to the noise I'm getting. Mine is just one random knock/ping every once in a while at all rpms. I'm gonna keep my eye (ears maybe?) on it and see if there's any change. I'm pretty sure it's just a normal noise from what I've read.

Thanks guys