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Knocking...well more of a tapping sound, help

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98 outback 2.5 mt, car has 165000miles, valve job, head gasket replaced

 

when the car starts out cold especially in the cold salt lake city winter, there is a fairly loud tapping sound. when the car warms up, the sound disappears in the cabin, but still audible from outside the car.

 

When starting in fairly warm weather 60F ish, the tapping sound is faint but still there and kind of goes away after the car warms up.

 

I've been told that this could be the timing belt tensioner for whatever reason, could it be anything else?

 

when i did a valve job on the engine ealier this year, i replace the belt but not the tensioner.

 

Any thoughts?

 

Thanks alot!!

sounds from what you said like it could be a piston slap......its there when its cold and gone when it warms up?......

  • Author

explain piston slap?

 

i have had all the valves machined 5000 miles ago when i got the car.

this is just what is sounds like to me....it could very well be something else.......do a search or look at the bottom of this thread were the "related threads" are located and it should give you a good definition of piston slap as well as other valve train/ engine noises.....in short i believe there is excessive clearance when the engine is cold and makes the piston kind of slap against the clyinder walls....once everything warms up and expands everything seats well and the noise is gone.......

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