Trekkie

But considering that it doesn't make the sound when cold, and the noise was already there before the last oil change, do you still think it may be a lifter?

Thanks, that is a relief. I don't think I have a cracked block since oil is very normal. By the way, I checked the oil level yesterday and there were 3 litters needed to top it off. Either on a very recent oil change they screwed up or something else is going on. I haven't seen any leaks. Once I topped it off the noise was somewhat attenuated.

How can I confirm if it is a liner? What happens if a slipped liner is left like that? Will the engine eventually fail?

Thanks for all the clues. if it is, as it seems to be, a liner, what is the fix for that? can I replace that liner? do all have to be replaced? what is the reason they get loose on the first place?

P38A Noise.mp3Very interesting thread. My 4.6 HSE has developed the knocking sound. The garage diagnosed it as a faulty tappet but I have my doubts as it only happens when it has been hot. At first I thoought it was related to two water leaks that developed about the times when I was hearing the sound. After fixing the first leak it kind of went away but after fixing the second leak it lingered. I am attaching a sound file. I have never had thought the flywheel would be a possibility! Is there an easy way to see if the flywheel is the culprit or does the transmission and engine need to be decoupled?