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View Full Version : KA24DE-T Possible Knock/Detonation


S14Ryan
07-15-2013, 11:48 PM
Hey Zilvians,

I have a built KA-T with Crower Rods(among other things but only rods relevant), and I have recently developed a barely audible knock in the motor. About 500 miles previously I had done the rod bearings as I had developed a rod knock. One of the bearings was pretty toast but the journal remained okay. I polished all the journals and they all spec'd out to .002" of oil clearance. I used assembly lube and torqued to spec and all that jazz, so the job was done correctly. The knock is not heard on first start up before oil pressure built like when I had a bad bearing previously. It is a barely audible knock at around 2-3k RPM, and then seems to go away. The knock cannot be heard at idle and also goes away immediately after lifting off of the gas which leads me to believe it may be detonation/spark knock. I changed the oil and it did not help.(rotella 15w-40) I am just wondering if it could be caused by bad plugs/wires/cap/rotor? I have not done cap/rotor/wires in a long time but I did replace the plugs about 3k ago. I'm stumped as to what it could be. Car starts up and drives fine, it even boosts properly, I had been driven it probably 20 minutes after I heard the slight knock start to occur as I had to get the car home. I changed the oil and took it for another drive, got it up to 6k rpm and about 5psi of boost to see if it would get any worse(I had nothing to lose...) and it didn't get any worse, and if the bearing was bad it should have at least gotten worse but no. I'm stumped!

Any help would be greatly appreciated!