I see all these people going on about 'piston slap' and i havnt a clue what it is...purely out of interest could someone please explain??

Thanks,

Dunc.

 

When the bore of the engine goes oval and the piston is able to move from side to side a little. The engine would need a re-bore and pistons to cure this Not clever I looked at a sport the other week that suffered from this You can hear it by lightly revving the engine

Paul

 

My MY98 STi 4 has just come back from a £3200 engine rebuild because of this problem and apparently I got away lightly. I noticed what I thought was excess tappet noise and got it checked out. It was diagnosed as " Piston Slap ".
As part of the rebuild I had an uprated oil pump and cooler fitted, but most of the work done was to fix the problem.

 

What number of miles does this start to happen?

Getting worried..... most of the rattles I hear I put down to heat shields and Jacks....

 

What MY is your car ?. as on other threads the most prone years are MY 97/98 's. If its a UK motor you will be able to get it done under warranty, if dealer says its not a problem, cane him, beacuse the cure is a new short engine and he's just ducking the issue. Mine is an import so it was a case of raid the kids piggy banks.

 

96/97P STI on 50K. I've just found a mp3 of the noise, and I don't think I have it. Its quite a "gruff" "growling" and makes the engine sound like its really fcuked. But I'm changing the oil later, and will be removing the heat sheilds before long....

 

Dan

It isn't that loud send me the file if you like? Address in the profile

Paul

 

If I didn't know better I'd say the car in the mp3 file was a diesel...

The file is online at http://homepage.ntlworld.com/alan.leslie/

 

This used to happen a lot on Cossie's on the early days due to people tuning them wrong, all they were doing was winding up the boost and fitting bigger injectors, the excess fuel at low rpm was washing the oil from the bores and the rings were gouging the bore causing them to get larger than the pistons then the pistons would rattle about a bit, its especially noticeable when a engines cold.

 

Dan

That does sound loud but the noise you are looking for is the tappy noise as the engine is revved. Ignore the other noise. Is that a scoob engine?

Paul

 

You will know the sound its like a "clack clack clack " sort of a noise when its cold and on rev pick-up, not gruff at all. Get a good oil monkey to have a listen. I was lucky the lad I know through the garage when my Mrs works is into the Group N rally scene, and he recognised it straight away. Engine out and sent to Gwynnes in Oxfordshire. Can't speak highly enough of them, job well done.

 

Yep, its a sccob as far as I know. I found many links to it after doing a search for piston slap. I presumed that it would sound like a "slap." That tappy noise I have heard on every scoob engine I have ever heard, just to different degrees.

For the moment I'm gonna be happy with just sticking thicker oil in...

 

If your car sounds like a diesel when its cold, and like a scooby when its warm, you've got piston slap...

Dan

 

 

lol well i cant really tell which bit is supposed to be the slap bit lol
mines a little bit noisey and tappy when cold, but arnt all cars

im not that botherd, its sweet when its warm
its a 96/97 wrx on 58 000