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-   -   Does this sound like it's piston slap? (https://www.scoobynet.com/general-technical-10/815819-does-this-sound-like-its-piston-slap.html)

ImprezaBoy 11 February 2010 11:23 PM

Does this sound like it's piston slap?
 
No audio clip. but been told my engine's got a bit of piston slap and just want to confirm that's what it is, and not something more serious like rod knock, spun bearing etc.

Basically first thing in the morning is when it's loudest, it's pretty bad (imo) as it's idling first thing and as you're driving.

Then, when the engines warm, it's pretty much silent on tickover, but you can hear it (much quieter than when cold though) as you go up to about 2,500rpm then it seems to fade off. Also, the strange thing is that whilst you're acclerating up to 2,500rpm if you let off the throttle, the noise goes completely? It seems it only really happens idling at cold, or when under load (and VERY faintly when revving up to 2,500rpm when warm but barely at all).

Just confused that the noise seems to go away when you're off the throttle.

Besides that the car pulls fine etc. and drives spot on, just a bit worried. Triton reckon it's slap but I just wanna be sure it's nothing more serious as I understand slap's quite common.

Cheers.

(oh yeah, another thing is that the speed and pitch is pretty much identical to the engine speed/rpm, where as engines I've heard with a spun bearing or rod knock seem to knock at slower speed than the engine?)

BRAVEHEART_STI 11 February 2010 11:57 PM

i have this aswell mate very common on version 4 and 5 cars piston slap will deteriorate when the piston expands ( warms up ) as piston slap is caused by the piston being undersized when cold and basically slaps around the barrel ?

turn on ur car in the morning and allow it to get up to full temp without touching the throttle or driving the car , this is the best way to prevent damage and also try using a good oil eg: millers or super mobil 1

ImprezaBoy 12 February 2010 12:20 AM

Are your symptoms the same as mine mate? I.E it not being heard off throttle and only up to about 2,500rpm?

butlerwrx 12 February 2010 01:06 AM

Hi mate my mates car does this and has done 4 about 3 years lol

ImprezaBoy 12 February 2010 01:25 AM

Really? That makes me feel a little better tbh mate thanks lol. Does it make the same noise when warm at the same RPM's etc?

dj219957 12 February 2010 07:28 AM

what year is it?
my 93 wrx has piston slap and sounds knocky in the cold mornings. ive just got used to it. so long as it dont use oil its fine.

lee1184 12 February 2010 08:10 AM

My old (98 Turbo 2000) Scooby did this, i was told by the dealer it was piston slap i pretty much knew this already but they confirmed it as there was a time when quite a few people complained about it and were given a short-block exchange under warrenty.

harrisonl84 12 February 2010 10:44 AM

Yep piston slap still scares me sometimes. just take it easy when its cold dont go in turbo for at least 5-10 mins.

ImprezaBoy 12 February 2010 11:14 AM

Glad that's what it is. TBH I don't usually let it warm up at idle as I've always been a believer that it does more harm than good so I just drive off in the morning, but don't accelerate hard or go over 2,500rpm 'till it's warmed up.

As long as it doesn't get worse I guess...

Oh and it's a 1998.

JohnD 12 February 2010 11:37 AM

All the classic symptoms of slap. It goes when you close the throttle as the load on the pistons are reversed. '98 cars are prone.

JohnD

TonyBurns 12 February 2010 12:34 PM

98's were the biggest culprits, some 97's, very rare on any other model after that.

Tony:)

happydude303 12 February 2010 12:35 PM

i had it on my wrx to dont worry about and also if triton have advised that they now what there talking about i have used them for some time and they also rebuilt my engine and it sweat as a nut. ringo and andy vey are good bunch and there never come the old sh£t with you to try and get money out of a job oh and yeah let it warm up for a good five minutes before driving

ImprezaBoy 12 February 2010 12:42 PM

Yeah I had my APR's fitted by them a few days ago and a new thermostat and was very happy with their service, they really seem to know what they're talking about and also super nice guys. The price was great too and you pay what they quote which is nice! It worked out cheaper than Kwik-Fit lol.


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