Knocking noise coming from piston/crank
17 March 2007, 02:10 PM
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Knocking noise coming from piston/crank
Hi, I need some advice on why my scooby is knocking. I have been told its a common fault on scooby's. I have a 96/97 uk spec turbo 2000, I have been advised it could be my crank, or fourth piston slack or my oil pump not holding enough pressure. Scoobyclinic has quoted me £2500+vat to sort this and frankly i have not got this kindf of cash to spare at the mo. Any advice or ideas would be much appreciated. Thanks
17 March 2007, 04:14 PM
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if it knocks from cold and then quietens off after 5 mins or so, it will be piston slap which is coman on your year of car, don't worry about it .If it is knocking all the time ie when hot sounds like something more serious.
17 March 2007, 07:40 PM
#5
The diagnosis from scoobyclinic was quite broad, to say the least.
A short engine is the Block, Pistons, Conrods & crank Etc, The part that your Cylinder Heads & everything else bolts to.
Dean
17 March 2007, 08:40 PM
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Piston slap can & will still knock when hot if the vehicle has a bad case of piston slap, Just because it does it when it's hot, Does not mean it is any more serious than piston slap.
The diagnosis from scoobyclinic was quite broad, to say the least.
A short engine is the Block, Pistons, Conrods & crank Etc, The part that your Cylinder Heads & everything else bolts to.
Dean
The diagnosis from scoobyclinic was quite broad, to say the least.
A short engine is the Block, Pistons, Conrods & crank Etc, The part that your Cylinder Heads & everything else bolts to.
Dean
I believe a modified piston can by bought from subaru to cure this problem as it was a factory fault on the stated years of the car.
17 March 2007, 08:46 PM
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As a general rule the knocking dose stop, or noticably quietens off when the engine is hot , as the piston rings expand due to the heat greated .If the knocking still is presant and is the same "volume" as when the car is cold i would suggest some else is wrong as i quoted above. There are proberly hundreds of 96/97/98 impreazs driving around with this problem and causers the car no problems except a bit of embarassment to the driver .
I believe a modified piston can by bought from subaru to cure this problem as it was a factory fault on the stated years of the car.
I believe a modified piston can by bought from subaru to cure this problem as it was a factory fault on the stated years of the car.
All of the above is true, all im saying is that piston slap can still be apparent when hot & should not just be ruled out because of that.
Dean
Last edited by DeanF; 17 March 2007 at 08:48 PM.
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17 March 2007, 09:43 PM
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try and get hold of scoobysmiff, as we've just taken his short engine out, and its sound like the same thing, the bearing has gone on the 4th piston crank end, you should be able to get new bearings for around £50,
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