yesterday i just did regular maintenance on my truck 97 4.6L. I gave it an oil change, cleaned the air filter, changed out the rear diff fluid, and cleaned her up too. well when i cleaned it. i took it to the quarter car wash and sprayed down the motor to get some of the grease and stuff off. well that was last night and now this morning i start it up and i hear a loud screeching coming from under the hood. well i am wondering if the engine cleaning has anything to do with this noise. Last month i replaced the alternator w/ pulley, and the idler pulley. it almost sounds like its the water pump but i am not sure. Any help or guidance would be greatly appreciated. Thank you.

 

sounds like you got soap on the belt. If you didnt replace the belt maybe you should. if you did get some belt cleaner.

 

now the noise only starts at around 2500 rpm. anything below that it is gone. Soap can really cause this? ill try some cleaner.

 

soaks into the belt... I would take the belt off and scrub it with a mild wire brush... maybe a brass brush