What causes a chirping noise on an '89 toyora supra even after the head has been replaced?
Can you tell which area of motor it's coming from? If not use vacuum cleaner hose or piece of PVC pipe hold one end to your ear while carefully positioning the other around the motor. The chirping will get louder the closer you get to the problem. I would guess a pulley, belt or tensioner. Might even be a timing tensioner on your timing belt/chain.
dandy has a good suggestion there. A valve job, or replacing a head, is major surgery and re assembly many things can get overlooked and not put back together quite right
Many many things. Metal on metal spinning, serpentine belt . Belt tension pulley bearing etc.
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