Erick, 5 Corners Auto Repair in Central NJ did the plug weld to your sleeves...?
And it stopped the ticking...??

I ask BC I am not to far from NJ, love my disco, hate the ticking, and already brought the temps down to around a constant 195* to no avail. (Gray 180 thermostat from Rovers North)

 

Unless the engine, bores, rings and pistons, are knackered it's unlikely to be piston slap per se although it occurs to a lesser extent on most engines.

What causes piston slap? | Ask.com

 

Have you fiddled around with the ignition or valve timing recently? are you confusing piston slap with pre-ignition (pinking), an easy mistake to make and they sound very similar to many.

 

Sorry about the late response

YES, he 100% fixed my tapping. Give him a call, he's a good dude and he quoted me about 1500-1800 for it. In the end, it came out to around 3100 because he had to replace the radiator, swap out sway bar, tie rod ends, rebalance, etc but he does FANTASTIC work.

 

While your reasoning sounds fine and good, seriously, the majority of these vehicles develop a piston slap, if not all of them on the stock cooling system. Because it's not an inline setup, the coolant simply circulates through the tubes and not through the radiator once the thermostat hits 220 degrees. Which, by the way, the 220 degree thermostat that comes stock with the Discoveries is completely stupid and far too high of a temperature to open at. The entire cooling system is made by monkeys. If your vehicle does not have a tap, do NOT keep running it with the stock cooling system. You must change it or it will develop a slap. I'm not sure about your vehicle as you're driving a TD5, but I can tell you with all gasoline Discoveries, this issue will occur.

 

i think someone might be confusing piston slap with a slipped liner, two completely different things.

 

I think we could call it Liner Slap