I love all this on line diagnostics though because you get so much feed back from everyone and it forces you to really think through it.
Yep.
Chirp scenario 1:
Exhaust leak; except, this has to be constant. So, chirp-chirp-chirp is the constant.
Belts chirp; more or less in an inconstant way. But some will chirp every cycle spin and remain steady like an exhaust leak or chirp.
Chirp scenario 2:
Belt chirp has to come around every few times, then the chirp occurs. But this may not occur but after so many revolutions and returns. So, some belt chirp are sporadic or come and go.
Cam/roller gall will 'float' or the roller really spins. The way the cam is cut, it rides on the edge of the roller's flat surface, spins and lubes this way. This too is inconsistent searching for 'chirp.'
A. Tighten exhaust clamps.
B. Use bar soap, rub the belt teeth somehow to deaden the noise... If it is belt related.
C. Tear down the engine and inspect, or cut open the oil filter cartridge. This will show evidence inside the pleats. If you have metal debris, the engine is going south.