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-   -   Piston Slap MY97....? (https://www.scoobynet.com/general-technical-10/475855-piston-slap-my97.html)

STI -V4 07 December 2005 12:47 PM

Piston Slap MY97....?
 
Hi peeps,
went to look at an Impreza Catalunya with a friend of mine as he has very little knowledge about scoobs..
anyway car seems fine - 1 owner 120k fsh and all the rest.. only thing is on cold start sounded a bit tappety..? from the back of the engine nr the top of exhaust..
Owner said its pistonslap and has been doing it for years - since the car was around a year old..!!
Sound goes away when car is warm (about 10 mins after start up)

So my question is my Friend really likes the car and the only thing putting him off it is the piston slap.. is it anything to be worried about - will it get worse and knacker the engine or not..? Is it repairable - how much?

car is completely standard and my mates gonna keep it that way.. never heard this before however my past impreza's have always had decat's followed by full zorts systems so i guess i wouldn't hear it anyway :)

Cheers

ALi-B 07 December 2005 01:11 PM

First make sure it's piston slap your hearing, should sound louder on mild acceleration of the engine. Lessens when you back off.

If it stops when warm and within 10mins then thats fine really. If it was doing for longer (i.e 30mins) or when hot, I'd start to worry.

Effects are increased oil consumption as the bores wear out of round. Cure is new pistons, with the very remote possibility of rebore or new block depending on bore wear (if any). So is best left until the engine sufferes a more severe problem (such as bearing wear/failure) and sort it out then. Cost will be roughly teh same as a full engine re-build, as at 120K you'd replace the bearings as a matter of routine while the engine is apart.

jaytc2003 07 December 2005 01:16 PM

personally I wouldn't touch it. If I had bought a new car and it started doing it since around a year old I would want the dealer to sort it.

It isn't a feature that subaru had, so I wouldnt accept it as it could lead to something expensive in the long run.
There are plenty of cars out there, just tell your friend to bide his time.
Just my 2 cents

ALi-B 07 December 2005 01:27 PM

Almost all Rovers and Renaults, and even some Hondas and BMWs have piston slap when cold from new. It must be understood that controlling expansion and contraction of lightweight alloys and iron, whilst maintaining a safe clearance tolerance to avoid seizure is a tricky task. ;)

My 2nd engine still slaps, after the first was replaced with a complete new short engine under warrantee for the very same reason (although this one stops within 5mins, rather than 15mins which the old one did and is nowhere near as loud).

My main concern would be the bearings @ 120K.

hmhaga 07 December 2005 01:44 PM

>It isn't a feature that subaru had

To rewrite the Microsoft "it is not a bug, it is a feature", I'd say that piston slap is a feature of the MY97/98 ;) I've had piston slap in my car (MY98) since new as well, now passed 160.000 km and a LOT of trackdays.

STI -V4 07 December 2005 01:58 PM

Thanks guys - the owner did say he took it in for the dealers to see when it started and they did say they would repair it under warrenty at the time - however when they said it was an engine out job and it could occur again he didnt bother getting it done..

And yes goes louder when under a bit of rev and quietens down when you release the throttle.....

only does it between say 1000rpm to about 2300rpm but yes the car was left started about 10 mins or so then you couldn't hear it at all....

Cheers


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