Guys,

 

I was driving down the A13 lastnite and it was around that time i started hearing a 'knocking' noise from the engine!!

After calling Andyduff and some more further investigating i realised that it was only happening from around 2500rpm to bout 3500-4000rpm???? it doesnt happen b4 or after?!?!

 

Sounds quite bad, thought i blew me engine, have i? does any1 no what it could be? The knocking sounds like when u hold the end of a stick to a bicycle wheel.....

 

thanks jaz

sounds like big end bearings to me, the 200sx's are renowned for them and that sounds the same !!!

Is it a loud sound ?

 

Could have something to do with the VTC-solenoids, but usually this is barely audible.

Sometimes the plugs of the detonation sensor and the VTC solenoid are swapped (since they are the same)

 

-Eric

Thanx 4 the replies guys,

I dont think its what u said Eric cos its loud. Olly, big end bearings, what & where r they? y would they go? i just recently put in my boost controller, could the extra power screw the bearings?

 

also would it be cheap to repair!!??:(

 

thanks

jaz

sorry 4got to mention that the noise didnt really occur this morning when it was cold....dont know what that means?

If its a big end and loud I dont think it would care what the temp is. Is it Auto? I say this because drive flex plates can break, and sometimes be on and off for a while. And Cats can make noises too when they break up. Could be anything, more info needed..

Hi Mark,

 

Yeah mate its an auto, 90' uk spec. ive had loads of probs with the box, acting erratic etc but the noise is there even when the box is not ingaged ie in N or P....

If its a run big end bearing then a cold engine with thick oil can mask it until warm although you might hear a clear knocking for a second or two while the oil pressure rises. Look out for lower hot tickover oil pressure than usual as the oil obviously leaks out easier from the run shell.

 

Other symtoms can be it goes quiet when the engine is under light load at lowish rpm but noisy when simply revved with no load on it.

 

Also it is a clear metallic knock knock type sound?

 

Dont keep driving if you suspect this as you will damage the crankshaft if you havent already.

 

As to whether there's a connection with fitting a boost controller - yes if you thrashed it a lot lately and yes if you are not gentle with it when cold.

 

Could be expensive - hope it isnt a big end gone.

I had a spun bearing and i found that the noise was there at around 2500 - 2800 rpm onwards no matter what i did, unless i was wot from below that rpm (you then probably just could not hear it) i think you can have it diagnosed by pulling sump of.

not worth driving it further, like Willio says, if youve damaged crank you run risk of doing far orse damage, ie throwing rod through block ect.

Originally posted by jaz

The knocking sounds like when u hold the end of a stick to a bicycle wheel.....

 

Have you checked your alloys to make sure no-one stuck some spoke reflectors (free with Frosties) in there? Other than that I can only suggest you check someone isn't trying to slow your Zed down by wedging their Dunlop Green Flashes between the tyre and the frame..... :D

 

Sorry - just a bit bored and your comment resurrected long forgotten memories of my BMX. Hope it isn't anything expensive :)