Knocking

[reflex]

still havent got my power fc tuned yet. its booked in next thursday. Just a bit curious about one thing when i turn my car over and its dead cold I get a knock reading of about 55-60. driving its fine, knock doesnt get above 10-12 but just when i start up, anything to worry about???

[Tommyk]

Mate

I get a similar sort of thing. My knock goes up to like 100 on startup.

Now there is absolutely no way you could get knock at < 500rpm. My tuner attributed it to a noisy starter motor

[Thunderbolt]

Could be due to the oil draining back to the sump after it has been sitting for a while. When you restart it, it takes a couple of seconds for the oil to get pumped back up and start lubricating again.

[R31Nismoid]

ive never seen more than 12 on mine.

[CoolingPerformance]

Pistons may be rattling a little as they are cold and have not yet expanded making a knock reading.

Thanks

Jordan Ross

http://www.CoolingPerformance.com

[reflex]

that would make sense since it is bloody freezing here. the car gets tuned on thursday so ill post up the results on friday hopefully

[Chris32]

Could also be starter motor hitting the flywheel

I 'accidentally on purpose' engaged my starter motor while my car was idling to see if it would pick up the noise.....

63 on the hand controller........

Chris

[VIP32]

My power Fc produce knock 1 on start up and 18 max on 1.3 bar of boost, Rb25 Hks 25/30

[reflex]

when i first plugged in the power fc there was no knock on start up. it has been colder lately. it gets tuned on thursday so hopefully all issues will be solved.

[R31Nismoid]

well i doubt pistons.

i was using forgies in my old 25 and i never had issues with knock.

I reckon check starter and other things

[reflex]

im pretty sure its the starter motor cos when i watch the knock reading it jumps up when the starter motor ticks over, its just a really quick impulse. is the knock sensor really sensitive or is there a problem?

[Mik]

im pretty sure its the starter motor cos when i watch the knock reading it jumps up when the starter motor ticks over, its just a really quick impulse. is the knock sensor really sensitive or is there a problem?

<{POST_SNAPBACK}>

I reckon it's due to the knock sensor circuit picking up the back EMF when the field in the coil on the starter's drive colapses. No idea why some do it and others don't though.

[rob82]

I reckon it's due to the knock sensor circuit picking up the back EMF when the field in the coil on the starter's drive colapses. No idea why some do it and others don't though.

<{POST_SNAPBACK}>

I think you hit it on the head there Mik. Probably a combination of the two. I disconnected the EFI fuse today and ran the Peizoelectric pickup near the starter motor what do you know, lots of noise when turning over.