[1996 4.6 P38 - knocking sound on idle]

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?

[1996 4.6 P38 - knocking sound on idle]

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.

[1996 4.6 P38 - knocking sound on idle]

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

[1996 4.6 P38 - knocking sound on idle]

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?

[1996 4.6 P38 - knocking sound on idle]

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?