I had Noisy clicky Lash Adjusters. I removed all the lash adjusters and did a 3 step diesel cleaning on them and put them back in. The clicking went away after running the engine but returned later on. I was going to buy new lash adjusters but I discovered and oil leak from the Crank Shaft Position Sensor Housing/Bracket. It connects to the right side of the 4 cylinder 4g64 head via 2 screws. On my car it was sealed to the head with some kind of RTV sealant which is NOT the correct way to seal this part. I bought 2 oil resistance O-Rings and slid both over the part which inserts into the head sliding the second O-Ring over the first to make a wider and tighter seal. So far the oil leak is gone, and since this fix the lash adjusters immediately went silent.

1. clean the rtv off the 2 surfaces
2. O-Rings
3. install -careful it is machined aluminum and will crack very easily if you over tighten the screws. There may be some exposed threads on the screws but it is a wider/thicker gasket now and will not need to be tightened as hard has the old one especially if it was RTV.