WRBlu

My MY03 WRX has developed what I would describe as piston slap, this developed soon after the 20,000M service - 07.2004

The vehicle was checked a couple of times by Cutlers of Streetly and they fitted a replacement cam belt pre tensioner. This did not affect the noise at all. Cutlers re checked the car and reported that:

“when the vehicle is ticking over hot or cold there is a piston noise from both rear o/s and n/s cylinders. If the tick over is speeded up the noise increases then goes off as the revs get higher”

The noise is not there when starting from cold but once its warmed up after 5min the noise starts, the noise does not go away when hot.
Its a ticking/light metallic knocking only noticeable from around 700rpm - 1300rpm. It rises and falls in frequency in time with the engine rpm and is particularly noticeable on a rising throttle.

Cutlers recommended a replacement short engine but eventually only got warranty authorisation to replace faulty pistons.
This work was carried out on 14.02.06 and I assumed all would be OK but having given it a few weeks listening the sound is still there.

Piston slap is known to affect 1998 vehicles, something must have been done to subsequent model year engines as I have not seen any reports of piston slap affecting MY03 onwards.
I can only assume that I have a faulty motor.
Or if the noise is supposed to be normal then these engines must have a design fault?

The noise was not there up to 30000k so since then something must have gone wrong with the engine in my car. Can anyone confirm my suspicions, if not does anyone know an expert who could diagnose this problem?

McWRX

The noise you describe is similar to heat sheild / broken CAT noise. Although if you have had it in the dealer am sure they would have found this!?

I have heard good things about API - perhaps give David a call there to get it looked at?

[Davey]

Could even be cluch/flywheel related being at the back of the engine.

lightwave693

slap would be there from cold and go when hot unless its extreme.