Right after buying my disco I was horrified to hear the dreaded tick/knock. I was certain that it was a slipped liner but a blocked lifter was a hopeful situation so I through in a bottle of rizlone. Lo and behold, the tick went away...

So several months ago, I let the oil get a little low, only a quart or so and the tick came back. Added oil, tick dissapeared.

Well, now it's back. However, It only seems to crop up at the end of the day, after idk how many heat cycles. Doesn't matter what temp the coolant hits, It doesn't tick until after a full day of driving.

I don't think this is a liner issue because there's no water in the coolant and it's not overpressurizing.

A bottom end bearing doesn't really make sense to me, I would think it would be constant. And a bad oil pump should cause symptoms at as soon as the oil thins out right?

I'm still leaning towards a blocked oil passage but the fact that it consistently waits till the end of the day is baffling.

 

Unless working 3rd shift the day's end is usually near the day's high temp of the day.

What weight oil are you using?

I experience the tick when at operating temp soon after purchasing my D2. Mine went away after simply running down/back I-95 for an hour. Have since only used 20w-50 syn oil and tick has not returned.
......

 

Not the end of the work day, happens after dark, so 8:30 or later.

Using 15w40 rotella currently.

 

Have you listened with one of the stethoscope dealies? I notice that my top end is more quiet with 15w 40 Rotella.

Maybe throw in some CompCams Break in fluid with the next oil change? Could maybe clean it? Run seafoam in the crankcase?

 

After my experiences I've had this week from my SeaFoam adventures I've been reading about it. The stuff is awesome... Unless you don't follow instructions! Put SeaFoam in the crankcase about 300 miles before your next oil change and monitor your engine oil's color. Some people have found out that their engines were extra dirty because their oil got too contaminated and clogged up the oil filter. This can lead to catastrophe, so just be smart about it.