MazdaMitch no misfire. Oddly, it only knocks when the engine has NO load. If you'll remember our convo before, I thought it was an exhaust issue. It seemed like it was, because it changed, or went away when I moved the exhaust around.
Here's the scenario:
Engine sounds great, pulls great, under load, going up hills, etc. Sounds great, runs great, decelerating. It sounds like a "rod knock" when it's under NO load - and ONLY then.
I can't really pinpoint the sound, just yet. I am going to get a stethoscope and check around the block.
There's no metal in the oil. However, after getting off the interstate, the oil light was flickering at the stop light when I'd let it drop to idle. I'm running 20w50 synthetic. Once the engine cooled down from running on the interstate (about 1-2 minutes of 45-55mph) the oil light went away. The engine temps are good, what I mean by cool down might be better expressed by the oil temps dropping, since the engine isn't working as hard. Again, the oil light only came on (flickering) at idle.
It was about this point (after running around 50mph) that the knock started happening; only when the engine had NO load - just cruising in flat areas. Once I accelerate, or decel, it's fine. Idles nice, too - no clattering, etc.
If I had to guess, it's coming from the top end, back cylinder - that's where it's obviously loudest to my ear. I had planned to do a performance rebuild for this engine, but not this soon. We're trying to move and this couldn't happen at a worse time - well it could be worse lol - you know what I mean...
If anyone's been here before, let me know what you found - hopefully I can get this figured out quickly, otherwise, I'll be yanking this engine out.
