PISTON SLAP or something else ?
 

Hi Guys. At first sorry for video quality. Hopefully you'll be able to hear that sound. Subaru Impreza Wrx Sti V2 Import 90,000 miles. When cold it's pretty loud but after gets fully warm it goes away but not completely ! It is much more quiet but still can hear it. It's sounds like a Woodpecker. I own this car for over 2 years now and that sound didn't go worst, it's still the same. When engine is fully warm you can only hear it when revving, NOT on Idle. What do you guys think? PISTON SLAP ?

http://www.youtube.com/watch?v=KOJhZBRVoBI

sounds like a bottom end rattle to me but i might be wrong

sounds like piston slap to me mate,doesnt sound like anything to worry about imho

My old wagon had the same noise and i had that for almost a year and nothing went wrong with it.

Also my bug has just started to make the same noise, you can hear as the revs drop, not as loud as that though.

Mine's currently of the road but will be getting it checked over before it comes back on, hope it's nothing to serious!

Mine developed some piston slap, dissapeared when warm( got told its nothing to worry about) then i could hear something when warm and when reving it. I have since taken it to get sorted and diagnosis is the piston slap caused scoring of the bore and piston and then that knocked the bottom end out....=S

Piston slap,mine does the same, dont they all ?

This is Big end LOL

http://www.youtube.com/watch?v=tIQjn89dREc

lean over the engine and by hand, rev it up and down slowly. if the noise comes at a sertin rev range and is not there at other, the chances are it could be the ends are on there way out

noise
 

Hi have you had the car up on a ramp might be worth checking the heat shield around the exhaust pipes they are suspect to cracking and making a noise hope this helps.

piston slap. sounds like mine on a cold morning.

Thank You Guys for your opinions and sorry that didn't reply earlier. I've had some technical problems with my internet connection. Hopefully you're right by saying it's Piston Slap. To be sure I'll check with Subaru diagnostic. Once again Thank You very much.

Winker, I'm running without heat shield so It can't be that but thanks anyway :-)

my m8 car had some kind of piston slapbut when he changed his headers to equal length the noise went

I was told that when revving the engine, if the noise is there as the revs climb & not as the revs drop, then it is piston slap. If it does it at as the revs are dropping after revving it, then it's something more sinister on the way.

Don't worry, if it gets proper f***ked, you will know...

http://www.youtube.com/watch?v=DIS5zjylb4c

Hi Tony,
So if it's true what you were told... I'm not happy :-( because mine is making that noise only when revs dropping. But as I said at the begining of my thread, I own this car for over 2 years and that sound didn't increase so... Hopefully it's nothing serious. I might be wrong but if that was something serious, it would be same loud all the time, but mine is knocking/tapping loud when cold and nearly goes completely away when fully warmed up so... it's sounds like Piston Slap.

You can also hear that sound when hold on certain revs (lower range), so not only when dropping revs down.
CONFUSED !!!

Found this when looking through youtube, might be something to look into.

Will be getting my belt and tensioners done when i get it back on the road, and hopefuly that could cure mine.

http://www.youtube.com/watch?v=UmZ1F8V8pc8

I've just had a similar knocking noise from the left (passenger) side of the engine - Subaru dealer took it in for diagnostics, and feared an engine rebuild. Turned out to be loose spark plugs on the left cylinders.

I can't say that is your problem, but check that as well.

Gareth

Cheers Gareth but I've changed my spark plugs 2 months ago and that noise is still on. I've had it before and after spark plugs change. So, it must be something different.

Have you listened through a long screwdriver to see if it may just be noisy tappets? I had what I thought was a dying engine in my previous Scoob but turned out to be noisy tappets and nothing more!

No I haven't. I've heard about that method but using wood instead of screwdriver. How should I do it ? Where to put screwdriver/wood ?

When I did it, I put a long screwdriver on either side of the injectors on both heads. Put my ear to the plasti end and had a good listen. Several tappets were quite audible. Injectors were fine as they tend to tick anyway in my limited experience. I'm no mechanic so please don't take me as gospel.

Ask a tuner on here about the method, sure you'll get something more accurate :thumb:

Yeah, the screwdriver trick works better than I expected. Surprising what you can hear just by touching it around the engine with your ear on the other end.

I wouldn't worry too much about it bud.

Cheers Guys. Will let You know how it went.

got the same thing, slight knocking wen started first thing for about 2/3 mins, changed the oil, still the same, feels like oil not getting there quik enuff, is ur oil pressure ok, gettin mine checked soon, been told 'stp' might quiet it down, not sure if these engines like additives?? ive blown a v2 import 65k with no signs of wear or knockin (fairly cold engine+ sideways twice round a wet roundabout then holding 145mph for 5 mins shud do it ;-) b4 and bought a v1 with blown engine and had both engine swapped with new cambelts for £700 supplied and fitted, and both cars are still going strong, so my imo enjoy the car, save a bit of dough just in case and find a good/cheap subaru mad mechanic and become his best mate. good luck

[QUOTE=OcTag3n;9868411]I was told that when revving the engine, if the noise is there as the revs climb & not as the revs drop, then it is piston slap. If it does it at as the revs are dropping after revving it, then it's something more sinister on the way.

That's the accepted theory!

sounds more like tappets but could be wrong, would get your clearances checked, if it is then you wont be doing the motor any favours by just keep running it, of course you could just keep running it for ages untill a valve seat burnt out lol, n tbh tappets are a quick job to get done will cut fuel usage and improve performance of car :)

@Dubsy yes matey stp do an additive that you can use as long as the lifters arnt to worn, castrol used to do a special oil that was designed especially for this used to be a classic with the audi 80/90 motors lifters, not sure if they still do and if it will be any good for a scooby might be worth popping down to local garage and having a chat

I didn't think impreza's had tappets, instead they use shims. Tappets wear loose, shims wear tight . As your valve wears into its seat and re-shiming the valve clearance is needed you have thinner shims installed. Shim rattle is good as long as its not excessive. If they dont rattle there to tight !

how much does it cost to get rid of piston slap? What's involved in doing so? It's really annoying. My car sound like a deisel in the mornings, til it's warm.

@chooperman ahh ure probably right matey ive never worked on a scooby yet so was going on a normal motor:) and yep as you state if its shims then no probs