I am working on a 97 riv vin1 and it has a chirp/etch noise coming from the front cover area. have replaced timing chain,gears,waterpump,all belt pulleys,alternator,supercharger,p/* pump and it is still there. now only noisy at idle and noise is still there with belts taken off the engine. soundsw like an "erp-erp" from engine. pinpointed to front with stethoscope. need help fast, it is a customers vehicle and it just came back after 6 months. the only way it did go away was when i added BG brand MOA to engine oil after oil change. HELP HELP!Thanks.

That certainly sounds like valve train noise. Judging by what fixed it and making an educated guess, anywhere between the lifters and valves.

Any chance it might be the balancer going south?

2 and a half year old thread. Looks like it never got answered.