There's are other noises on the track which tend to mask some of the 'tap' but I'd say it sounds more like a manifold gasket blowing.
Is it loosing coolent in huge clouds of steam from the exhaust? Does the temp gauge go from cold to off the scale boiling hot in the space of about 30 seconds?
If it doesn't do any of those things, then I suspect that it isn't a slipped liner.
coolant burning will remove any carbon from the plugs so they look like new.
normaly if they is a tapping it can either be
1 worn cam
2 worn follower
3 worn rocker arm
4 slipped linner
5 cat
6 exhaust blow
7 false teeth in glove box
coolant burning will remove any carbon from the plugs so they look like new.
normaly if they is a tapping it can either be
1 worn cam
2 worn follower
3 worn rocker arm
4 slipped linner
5 cat
6 exhaust blow
7 false teeth in glove box