What oil did he put in it and what type of mechanic is this?

Thin oil or thin synthetic (less than 15w40) will often have these results.

You need to be going to an independent land rover only specialist, not a dealer or a "foreign" car shop. the latter see LR owners as a walking stack of $100 bills and don't always know the specific details related to these trucks... like not using thin oil.

Change it again to Rotella 15w40 and report back.

 

x2 on the marvel mystery oil...


I have added a cup or so of a/t fluid to quiet up noises...


restored 154 m998 hmmwv's last year and some of the rebuilt engines didn't sound too good upon startup. splash of fluid into the oil and presto lifter noises quieted up and haven't heard them since.

 

I used Mobil One 15W40 synthetic for one oil change. The lifters started getting noisy.

I spoke with my buddy who owns a LR shop. He says to go back to organic oil. The reason being the old push-rod valve designs on our engine is more conducive to organic oil.

I switched to Rotella 15W40 and the lifter ticks have pretty much gone away.

 

use Rotella 15W40 regular oil, i made the mistake of putting in 10-40 sounded like the engine was filled with marbles