My truck is a 2005 5.4 3v screw. I have a noise that happens when it is cold outside. If I can let the engine warm up it does not happen. The noise occurs after driving a little. It seems to happen just before the thermostat opens up. It sounds like a deisel engine. I put the truck into neutral and the noise will gradually go away. It sounds like the thing is going to blow up. It usually does this a couple of times until the thermostat is open. I have read and read and read but can't seem to find someone with this situation. I was originally thinking cam phazer but the noise does not happen at idle. I have noticed that it takes a couple of seconds for the oil pressure gauge to come up when cold starting. Also the check engine light has come on. I went to Autozone and had the codes pulled. they are Cam sensor bank 1 failure and Cam sensor bank 2 failure. After the engine is warm she runs fine. Any thoughts?

 

Any way you can make a recording and install it here so we can hear it? First thought was oil filter brand and oil but you say it has to be driven a while before this happens. Can you get an inexpensive mechanics stethescope and try to locate the approximate location? Have you tried removing the serpentine belt to determine if its a FEAD component, although you are getting a engine light so it may be the chain tensioners. How many miles on the truck?

 

The truck has 76000 miles on it. I am not sure if I can record the noise because it only happens while driving. Not sure what a FEAD componet is but I will look it up.

 

FEAD = alternator, power steering pump, etc. Anything driven by the serp belt.