Excess Engine Oil Consumption on Toyota Avalon

Problem Description and Possible Solution

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.

Problem Data
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Average mileage: 128,280 (12,000–205,000)
Engine affected: 3.0L V6
7 model years affected: 1997, 1998, 1999, 2000, more2001, 2002, 2004
20 people reported this problem
Viewing 1 - 10 of 10 problem details
sludge in engine.

change oil 3/5000 miles.

not fixed.
There was built up sludge from oil changes at 5,000 mile intervals instead of 3,000. They cleaned out the sludge and replaced a few parts in the engine that could not properly be cleaned.
Sludge build up in the block.
Have had problems since I bought the used car. interesting that others have experienced the same problem. Will check on these sights before buying my next vehicle. Brought this up to dealerships repeatedly. Have gone through numerous (at least 5) PVC valves!
Car was to the point of oil contaminating the exhaust system at about 135K miles. Previous owner didn't change the oil frequently enough and this all resulted in top of motor replacement. Sludge cleaned out now (i hope) and it no longer smokes profusely like it used to.
Only cleaner I found that worked (I tried 5 of them) was Auto Rx. follow the instructions completely.
Sludge accumulated on the underside of the valve covers in spite of scheduled Mobile 1 oil and filter changes every 4,000 miles (Mobile recommends every 7,000 miles). Don't know if the oil was the problem or moisture condensation/oil mix (after engine shutdown)caused the sludge. However sludge eventually got into the valve guide seals and caused heavy oil consumption (1 quart ever 100 miles) which ruined a catalytic converter. Cost of the fix ? Toyota dealer charged $3,416. No idea if it will happen again. Changed to total synthetic Amsoil 5-20 and Amsoil filter. Love the car but thinking about installing a small block Chevy and converting to rear wheel drive (did that to a Nissan Altima).
Oil was being blown out the exhaust (white smoke) making it look like it was coolant but the oil was leaking rapidly, not coolant at all. The entire engine had to be cleaned out due to sludge buildup and I am only going to run synthetic oil from now on to avoid the problem again.
Just started useing oil very bad. I took off front valve cover and holes in head was stoped up.. I could not get the back cover off. This is a very good and clean car..Help....
sludge stopping up the PCV system causing blown valve cover gaskets and engine had to be cleaned and flushed with valve cover gasket replacement.