I started to hear "the tap" recently. Since the extended warranty that came with the truck is up in about 6 months, I decided to take her in for a look at the cam phasers. Initially, Longmont Ford gave them a $4000 estimate (they threw in an oil pan gasket and a new IMRC). The warranty company didn't like that so they sent out "an adjustor". The adjustor agreed that I had a cam phaser problem but wanted to see the engine openned up to make sure there was no sludge. I went over the dealer last night and took this picture. I don't see any sludge...damn clean for 80K miles if you ask me.