My '94 22re is making quite a lot of racket under load. It doesn't have to be a heavy load either. Just slowly accelerating from a stop will cause it to ping, but it is very loud when cruising down the road. At an idle, and when revving up at idle, I don't hear it.

HG was recently replaced, and things were fine for a couple weeks after. Then, one day it suddely started to ping.

Valves are adjusted properly. Timing is set to 5 degrees with jumper installed. I usually run 87 gas with no problems, but I put in premium for one tank to see if it made a difference. Nope! It's not a rod knock. It's not the injectors.

I noticed that the engine recently lost compression. It's now at 140-150 instead of the 175 before. And the cylinders lose air when left to stand for a few minutes. I'm not sure, but it might be burning oil. I haven't driven it enough lately to know.

Any ideas? My wife's cousin is a Toyota tech, and he said that oil in the combustion chamber can lower the octane of the fuel. Well, like I said before, the premium didn't make a difference.

Just wondering if anyone here has had a similar experience?