'91 Ls400 Engine Chatter

[Evan Ruff]

Hello,

I've got a 1991 Lexus LS400 with around 81,000 miles. The car is bulletproof reliable and has never given me a problem. I'm noticing a strange chatter coming form the engine. It sounds like a clicking/tapping sound and seems to increase linearly with engine speed. It sounds like it could be coming from the head but I haven't really poked around in there too much.

A relatively experienced friend of mine heard it and diagnosed it as "valve sticking," but it seems slow enough that it couldn't possibly be that.

Has anyone experienced this kind of problem before? What other checks should I make to the engine to help track it down?

Thanks,

Evan

[monarch]

The owners manual advises to have the engine's valve clearances checked every 60,000 miles. You may have a few valves that have developed an excessive amount of clearance, creating a tick..tick..tick type noise, especially after the engine has warmed up and is idling. So I'd take the car to a Lexus or Toyota dealer and ask them to check the clearances and to advise you if any are out of spec .