The headgasket was just replaced. And the head was machined because it was slightly warped. After the repair it drove fine for a day and then started pinging. And has gotten really bad. I've changed knock sensor and MAF. Strange thing though is the knocking stops when I disconnect the MAF. It sounds like the computer is advancing the timing too much but I can't figure out why. I did get a trouble code P0075.(Oil control valve). But cleared it and it hasn't returned.

 

reset ecu

 

I think that your headgasket is blown again. The problem on my engine whas that the headgasket was not tightened enough (compressed) from factory. Take out one cyl head bolt and check the end of the threads if its damaged. On my engine the threads on the top deck was too shallow so the headbolts hitting the bottom of the threads and didnt compress the headgasket.

I hope that im wrong.

 

Make sure tbelt tensioner has not lost hydrolic presseure can cause cam.advancement under load.
Oil pressure control valve also assists in cam timing.
camshaft also known to twist if engine has overheated putting timing out.

 

hey mate, I’ve had this diagnosed. I thought it was carbon build up or the thrust bearing, I had my clutch replaced and I was surprised to still hear the same noise but even louder.
I had it diagnosed and all it is, is your transmission. Purchase the gear box from wreckers for under $600 aud. Although I will say when you replace it with the new one, you need to use all of the old gear cogs and diff, the mouse simple comes from the axle or whatever you would call it ( the rod that the gears are on. Not sure exactly how it works but this is the reason your car is knocking.
it was getting on my nerves for over 2 years and I was stressing every day and night and trying to figure out solutions. Hope this helps 12+ years later.