Seca RV

I have a 1992 Seca RV AE93 I am the second owner from new and AE93 is on the compliance plate only difference is the RV model has 1.8 litre engine multipoint injection factory fitted with am/fm radio cassette and cd player and a rear spoiler

I have a 2004 Camry Altise 2AZ-FE has a noise coming from the drive belt area have replaced tensioner pulley also water pump and Serpintine belt and noise is still there not idle but under load spray some belt slip stop on and noise is gone for a couple of weeks then it is back has anybody have any ideas to find the issue