This isn't super important, but while I was here I figured I'd ask. When I drive my car under load (as in accelerating, not just sitting still and revving), when I get to around 3500-4500 RPM it sounds like I have some sort of a knock but it goes away after about 4500-5k. The car was my first stick so I drove the **** out of it and I'm about 2 months away from a motor swap, hence why I could understand a knock (on top of the motor just rolling over 190k). A while ago I had to replace the O2 sensor and one of the bolts broke on the 2nd part of the two piece mani when I was putting it back on, just wondering if it's actually a knock or if I'm just hearing the manifold leak. Sounds more like a knock though . . . if I drive it conservatively can it last the two months?

 

Check the ignition timing and buy gas at a different station.