You are getting into something you know absolutely nothing about and as your name states, looking 4X4Trouble.
Why the hell would you want to pull that apart to look at something that is not designed to be played with?
How about you change directions and address the issues you have regarding possible oil pressure/ticking issues? Have you done a full oil pressure test, stone cold at idle and 2000 RPM's and hot at idle and 2000 RPM's? If not, do that first then get back to us with what the 4 sets of numbers are. Then go to the LRO, at the top of the D2 section and read my sticky regarding head gasket and valve train noise that will show you how to determine what is causing your tick and how to repair it.
By the way, what oil, weight and oil filter are you using and how often do you change it?

 

Thank you all for your advice. It very much appreciated.. and you are all right.. First i will buy my own oil pressure guage. Second i do think there is some sludge in the oil system, and in needs some kind of flush..Mike i did the automatic fluid flush with no change. Third, if i still feel that the bypass and pressure relief valve are the issue i will shell out the money for a new timing cover..ouch $600. Forth, i will upgrade to the new filter and 15w-40 sythetic.

 

Consider same tasks, but in different sequence:

1. Change filter and oil again (you just flushed oil, so this will get out some more gunk). See https://landroverforums.com/forum/di...estions-46975/ for a filter that will provide an immediate boost to oil PSI.

2. Test with oil PSI gauge. Let the results point your next actions.

3. Consider a front cover from a donor engine. Not a 2003 in the range. If salvage yards are nearby. But try to eliminate the easy ones before dealing with the valves mounted in the cover. Perhaps Rover knows best, if the valve needs fixing, it probably has run that way for a long time and scored the walls of the cavity.

 

Look your getting in deep, I know of no good way to check oil pressure than through the oil pressure port. Problem is you wont find an adapter to change the oil pressure hole straight thread to a 1/8" NPT for the 15 dollar gauge your going to buy.

Which means you need to buy a new oil pressure switch, smash the end off and solder on a 1/8" fitting, like this one I've been using for years and years.




And then when you find out your oil pressure is low, you need to pull of the rear main cap, and 2 rod caps and inspect the bearings. an then when you find that your bearings are all worn out, you need to take all the main caps off + the starter so you can get to the cross bolts, drop your crank an 1/8 th of an inch, replace all your bearings. then you need to cross your fingers that you don't spin one the second you start the motor. Then if your lucky, your oil pressure wil go back up enough so oil once again gets to your rockers, that's to say your lifters arent shot and are the cause of your ticking in the first place...

What i'm actually trying to say is, turn your radio up louder.

 

You tend to use what is available (like the old oil switch) -
Like the write up on in-truck bearing replacement, we also had one from New Zealand recently. Eventually more of us will have to confront that.

 

Here's an adapter for the Rover oil pressure switch port.
The Brakequip Store
1/2" x 20NF male to 1/8" x 27NPT female

Of course, if you have a bad oil pressure switch lying about and can braze, that would be cheaper.

 

Thanks antichris, I will be ording that piece soon. Here's an update. It's been 2000 miles sence I replaced both head gaskets. I've noticed that the tick has gotten quieter.