Hi,

It is not yet fixed. We drove it a bit and runs strong. I changed oil again to 10w30 brand name oil with some Lucus oil stabilizer hoping maybe it would help but stayed the same.

Sound does not get worst when rpms raise or when driving around. It remains prominent at high idle mostly.

At this point, I am thinking the next and cheapest step to rule out the lifters, is to put new ones in.