My 02 Wrx had a broken exhaust camshaft on the passenger side, I picked up a set of used low mile heads off a Subaru Facebook page and got them decked and cleaned. I pulled the engine around Christmas and begin the rebuilding, I reused the pistons and put a fresh set of OEM Subaru piston rings along with a light hone.
Reassembeled the engine and it ran great, no noises or anything from it. Two days after the rebuild i decided to reflash the car with cobb sti injector economy tune and immediately after the reflash my engine began ticking :dizzy_face:. I reflashed back to my normal vf39 Cobb tune and its still there.
The noise is high pitched as though it is valve lash but I've checked and reckecked the valve lash and they're all within spec.
Sound appears to be coming from cylinder #4 but when using a stethoscope it sounds like it's from the head, like intake side of it.
Pulled the intake and swapped injectors from right side over to the left and the noise didn't move nor change
The tick does not change with load, making me believe it's not bottom end related and I didn't really mess with the bottom end.
During deceleration the tick is still there and has a direct relationship to rpm
Here's the kicker though, if during deceleration I turn the key off the noise goes away, but to my understanding there is no combustion in deceleration and injector duty cycle is 0% so what is different between deceleration with key on and deceleration with key off?
Engine used to run rough at idle and pulled low vacuum before rebuild so that's why I re ringed it and it runs sooo smooth now and pulls 19-20inhg vacuum.
Vf39, headers, up pipe, full turbo back exhaust, fmic, 2014 sti injectors, grimmspeed 3 port ebcs.
I really need help here guys, any input will be greatly appreciated, im a mechanic by trade so I refuse to take it anywhere but I'm stumped.