Dont add oil to water-- if u have to or want to oil motor get a spray lube unplug unit and at bottom remove debris guard only clips on and spray shaft and behind impeller if need to lube upper motor bearing unscrew housing and carefully pull up enough to lube top of motor replace housing careful of watertight seals and test pump oil poured into pit would only be pumped out and does not contact motor which sits in watertight housing