A sticking tappet is at cam frequency, which is half engine RPM. Slipped sleeve will be at 1 or 2 times engine RPM. Very easy to tell the difference when you have heard them. Sleeve noise is a horrible one, really sounds like the engine is tearing itself apart.. Tappet is a less scary low frequency tap.

The problem with engine additives is that they are very light/thin and disappear rapidly. They also have varying effects on viscosity, none of them good.

If you really want to clean out the engine, use a product that's designed to do so and for the entire period between oil changes. That's Shell Rotella T 15w40.. It has 3 advantages for your V8 : ideal viscosity, high detergent, high ZDDP.

I was a bit sceptical myself but put it in 1000 miles ago, and my tappet noise is being heard less and less often. It's very rare to hear it now, used to be constant when the engine was warmed up.

 

If I were you there's 3 things that a d2 owner must do to keep these beasts on the road IMO
Change to green coolant and at the same time replace your stat with a 180 stat
Get yourself an ultra gage
Replace all fluids

This is the min I would do right off the bat
My d2 always runs between 190 and 199 degrees f

 

Sounds exactly like what I had - it is most likely either Tappet/slipped liner or oil pump gear is shot or combination of all ...Either way not good and for me I was unwilling to put up with. Most importantly, find a good LR Indy in your area to start to diagnose and figure out your direction to take - this is my 2.25cents worth of advice. I got so mad and so sick to my stomach of all the crap that was starting to break on mine. PS Pump, steering pump, diff leaking, Transfer case leaking etc..... I also had just replaced HG's with less than 500miles and the NOISE started and so I bought a new rebuilt motor from Cannibal V8. This was the only way I was going to have any confidence the %$#^ POS would not break again. Now I luv my LR again ... but for many more reasons than just motor. It is a Trek and has history, everything has either been fixed or replaced or upgraded (see sig) one expensive experiment! All I can say is Good luck with your decision ....

 

I can probably help you. I'm willing to try pinning if an inline thermostat doesn't keep it quiet. Call me up.

 

Thanks for the feedback. I feel like this has been discussed ad nausseum. Oil pressure gauges. Is there a way to set one up temporarily? My initial thought was the pancake sender and wire it to a gauge and just place the gauge in the cabin and keep an eye on it that way. Once I confirm all is well I would remove it.

Or, Pepboys has them for $20 that run off a nylon hose. What would the other end of that hose go to?

Or, is there another way entirely I am not considering?
thank