I've got a toyota 22R in my car. A few weeks back water got mixed with oil due to the plastic timing chain guide being broken. I got the engine cleaned out and replace the timing chain. guides and gears. Now when I start it up cold or when it has been sitting for ~15 minutes, the is a very loud knocking or hammering sound for 2-3 seconds. After this time its gone. I thought the oil pump wasn't pumping fast enough so I got it replaced, but the sound is still there.
Any Idea on what it could be?