This 2019 Toyota Rav4 (MXAA52R) with M20A-FKS engine has not been serviced for 3 years and 65000km. According to the owner only the engine oil was topped up as required, this has resulted in extreme sludge build up and possible consequential damage. Engine is also noisy in the top end, possibly just a hydraulic lash adjuster. There are only 3 ways to approach this.
(1)De-sludge the engine, fill with new oil and replace the oil filter and hope for the best.
(2)Dismantle engine and assess the damage that may have occurred and quote repair.
(3) Cut your losses and replace the engine.
Owner has decided to replace the engine.