Help with issues with an EJ22

My EJ22 has been in my Van for a month short of six years and has performed excellently. It has now done about 135,000km and only required a water pump and two (2) thermostats. I change the oil early, regularly and using Subaru Australia recommended oil.

I just returned from a 4,000km trip to Melbourne. Just before I left the hydraulic lifter(s) started making a noise and now they are quite noisy. (A Subaru mechanic confirmed my diagnosis in Melbourne.) Basically he said to leave them as they are as they are causing no problem. BUT I don't like the noise.

Who has found success with oil additives to help re fill them? Or is this stuff just snake oil? I am going to change the oil this week so thought it could be worth a try. I've also read 500ml of ATF 150km before an oil change is as effective.

Who has removed and refilled lifters WITH LASTING SUCCESS? Any comments please? (Are there any special tools or consumables needed?)

ALSO, and more worrying is that as I came home last night, as I braked to a stop at lights, the oil pressure light came on! It went off again, but I could make it come on at low revs by braking moderately.
PRESUMABLY the braking moves the oil in the pan and reduces pickup by the pump, but in 6 years I have never seen even a flicker of an oil lamp on this engine before. I'd appreciate any comments.

Thanks folks,

Dave

you need to put an oil rinse throught the motor before you drop the oil on the next change. this will clean them out. Subaru recommend this every 20k or so. Just get a wynns one at a local shop.

Dave , there is no long term fix for your motor regarding the lifters , you can flush the motor with what ever you like and the problem will come back .

Subaru ad an aditive to the motor when the new oil is put in the motor

Regarding the oil light , I think your motor is on the way out possably a bearing . Does the oil light come on with the clutch in under brakes ??