tep... tep... noise when idling and slow going
 

Hello^^

My 2000 boxster S has some noise like 'tep, tep, tep' when idleing and slow going T.T

It's not airconditioner fan sound, when I off aircon, still tep tep.

after run and stop in parking lot, I can heard that.

about over 2000rpm, I cannot hear that tep tep sound.

Sometimes, keep idleling start 'tep..... tep.... tep....' and after it comes more faster 'tep tep tep' and sound disappear,
but, after high rpm and keep idleing, sounds comes again slow 'tep..... tep.... tep'.... and repetition comes faster... and sound disappear.

I search many articles in this forum...

I guess... do my water pump have noise, like this?

I can hear it at night or indoor parking lot. cuz sounds small.
It's smaller than radiator fan working sound in back of passanger seat.


How do you think about this noise??
Is it water pump noise?

thx for reading my poor question.

I'm no expert but I had a prev car (VW) with hydraulic tappets and when the tappets weren't working properly (oil passage abit stuck ?), I used to have the tapping noise that comes and goes... an oil flush helped but finally I had the tappets changed and no more noise.

On my 986, there is light tapping noise at idle but it's consistent and regular.

My approach ...
 

Inside or out side the engine? Remove fan belt while recording its path, leave access panel off. Run engine for only 20 seconds. If same noise, inside engine. If not then next step.

With belt still off, hand spin all idler pullys and all auxiliaries (water pump, alternator, a/c, etc). See if any of them wobble or sound funny when spun. When spinning them by hand, spin them only in the direction they would spin if connected to the belt.

Reconnect belt using the diagram you made before taking it off.