i have 2002 wrx impreza uk car.

i have a heavy pinking type of knock when i rev my engine steadly but is not there when i blip my throttle and is not there on tick over. HELP!

I dont want to take the engine out at the moment, unless somebody can point me in the right direction to the problem? any commen faults?

the pinking type knocking noise comes around 2000 onwards through out the rev range.

this knock doesnt happen on start up or at idle, just when reving steadly.


thanks very much with any help regarding this matter.

 

if you rev and lift off does it knock on the rev down?

if steady throttle only check the cambelt tensioner..

Simon

 

hello simon,

alittle more info for you, if you rev it up steadly and let go off the throttle the knock noise goes, and if you keep at required rpm the knock noise is present until you let the throttle off. Havent checked the cam belt tensioner yet but is there a possible problem with this?. the current mileage is 68000. i replaced the cambelt and tensioner at 54000. no problems until sunday just gone.

 

bump

 

If you fitted a new tensioner,torqued up the retaining bolt correctly and removed the retaining pin 14,000 miles ago,it should be ok but worth checking again.
Might also be the front pulley bolt loose and the pulley chattering on the keyway of the crank OR the dreaded big end failure.
A big end bearing which is just starting to fail will be evident around the 2-2500rpm range.
Might be worth getting a specialist in your area to have a listen to the noise.

Mck

 

what merlin said

 

this knocking type noise is more evident from the n/s part of the engine, possible more towards the back. sounds like a metalic noise too.

 

Its starting to sound more and more like the big end mate

 

or could be something trivial like a shield rattling?

Just pop it into any reputable garage which will soon be able to tell you.

I assume you don't have anything to monitor engine knock?

 

Loose turbo heatshield?

Ns04

 

no i dont have anything to monitor engine knock. its not the heat shield. ill going to take the engine out at the weekend and strip it down.

 

Drop the engine oil out into a clean container and check for "copper and silver" contamination/flakes - that would point to big end failure.

Mick

 

which cylinder is more prone to big end failure mick?

 

Sure it’s not worth a second opinion before you strip the motor, get a garage to have a listen. As Mick said check the oil and also check the filter, cut it open.

As to what bearing picks up is totally dependant on the cause, as far as det then it can be any. If oil starvation issue or break down then “usually” the first to suffer is the furthest from the pump..