Sludge can build up in the engine because Toyota did not recommend frequent enough oil changes. Lexus will sometimes offer a discount on cleaning the engine if necessary. Owners who changed their oil every 3,000 miles did not experience these problems. This sludge build up can lead to excessive oil consumption.
Excess Engine Oil Consumption on Toyota Highlander
Average mileage: 64,828 (42,312–75,000)
Engine affected: 3.0L V6
6 people reported this problem
2002 Toyota Highlander - 3.0L V6 75,000 mi, Visitor
Discovered oil consumption in Oct., 2014. Mechanic suspected sludge because I drive short trips around town. He has been adding detergent to oil and I monitor and fill oil reservoir as needed. He has not specifically checked for sludge (gelling). He informed me this was a problem with this engine due to, in his opinion, to a need for improved oil circulation via an engineering change.So far the engine is performing very well. I plan to trade the car in in September or October. Please note: When I bought the car, new in 2002, there was a notice about potential gelling. In October, 2014 I discovered on the internet a newspaper article about this problem. Toyota was correcting the problem for owners for 8 years after purchase. I'm not sure what they did.
2002 Toyota Highlander - 3.0L V6 72,000 mi, Visitor
Plan to have engine flushed with detergent.
2001 Toyota Highlander - 3.0L V6 70,000 mi, Visitor
Suddenly started using one quart of oil per 100 miles but only on highway 60 mph or more. Around town used no oil. Regular oil changes were always done.
2002 Toyota Highlander - 3.0L V6 42,312 mi, Visitor
3 quarts of oil in 500 miles, so much for toyota reliability. I sould have bought another Ford.