I ultimately had to replace the radiator on both my 2007 and 2006. The plastic was quite brittle, same as the thermostat housing and most of the plastic cooling parts. RockAuto has great prices on the NIssens radiator. With the radiator out of the way, you gain much better clearance and visibility to front of the motor. If you still have your factory radiator at 200k miles, you may be due for one anyway. The trickier part is removing the condenser coil unless you're prepared to recharge the a/c system.

Also, the VVT phaser gear fails by not locking when the engine is shut off. When unlocked at cold startup, it makes a very specific knocking noise for a quick second until oil pressure fills the VVT chambers. I did not have any timing related DTC's like you have. The rest of my timing components were in surprisingly good condition. I expect if your DTC's came about the same time you heard the noise, that you may have broken a guide, a bad tensioner, or stretched a chain far enough to set a DTC.

One more tidbit. The kit at Christopher's Foreign Car Parts. – CHRISTOPHERS FOREIGN CAR PARTS.COM is a nice kit at a great price. I did actually talk to him on the phone before ordering. His number is on the page for the LR3 kit.

Please keep us all posted! I'm curious to see what you find when the front cover comes off.

Good luck!