Engine Knock

[bulldog77]

i have a knocking noise that has increased in volume over the past few weeks. Under the vehicle, it seems to be above the oil pan. The oil is full and clear and has been changed every 4,000 miles. It uses no oil at all between changes. Has anyone had similar issues with a 2001 RX3000 AWD? My thought it could be a rod bearing. When I put it in reverse, it may go away momentarily but return. That makes me think it is not a rod bearing. Any thoughts?

[lenore]

What grade gas do you use? Also do you have any check engine lights.

[bulldog77]

What grade gas do you use? Also do you have any check engine lights.

Premium gas and no check engine lights are on. constant ticking/knocking sound at idle. It is definately in the bottom of the engine.

[mikey00]

This sounds like it could be a serious engine problem. If you put it in neutral and rev the engine slightly does the frequency of the knock increase indicating it is engine related. If so I would pull the front valve cover and check for sludge. If you find some it may be time to hit Lexus up on your 8 Year 120 day sludge warranty.