Clicking From Coilpack When Revs Hunt

[konect]

Hey all,

I started my car tonight and noticed that there is a clicking sound present from what appears to be coilpack 1 or 2. It was more obvious when the car was cold but then as it warmed up it became less regular.

When I got in the drivers seat I noticed that when the revs are consistent the clicking goes away. When the revs start hunting the clicking sound occurs when the revs reach the lowest point before going up again. Eg consistent ideal is 900rpm, drops to 800, clicks and revs return to 900.

Anyone know what this could be or experienced it before?

Engine: RB25

Computer: PFC

Coils: Splitfire

Cheers,

Konect.

Edited June 1, 2013 by konect

[KiwiRS4T]

Coil packs shouldn't click - is it the sound of the spark shorting to the head? Remove the coil cover and observe it in the dark or look on the coil pack for signs that it has been shorting out.

[konect]

Yeh it does sound similar to the coil shorting which was my first thought. I've done the lights off test and couldn't see anything.

The thing is, it only happens when the revs hunt. If they aren't hunting, then there is no clicking sound. That's what's got me stumped on this one :S

[StevenCJR31]

the revs are hunting because you are losing spark somewhere

ie the cylinder is not firing due to loss of spark

[SargeRX8]

As others have said the clicking sounds like a spark arcing where it shouldn't be. You can pull out spark plugs while the engine hunts to see which spark plug has no effect to the hunting. It could be a damaged coil which the spark is leaking from. Are you sure you're not hearing the injectors pulsing? If the engine hunts, from another cause, the rpm slows down and so does the injector cycle which what you *may* be hearing is your injectors opening and shutting. Again though, seems you've narrowed it down to cylinder 1 and 2 so what I'd do is swap cylinder 1 and 2 coils to 5 and 6 and see if the clicking moves to the back. Inspect the plugs, change if necessary and go from there.

Hmm also read how you said its worse when its cold. Usually if its a coil related issue the problem is more prominent when the engine is warm.

Edited June 2, 2013 by SargeRX8

[konect]

Thanks guys.

I swapped coils 1 and 6 today and got a second set of ears on the job too. We 'think' that it might actually be coming from under the inlet near the alternator. The sound still comes from the front end of the motor, but with a second set of ears we thought it was lower down rather than in the channel where the coils are. THe car ran for about 10 mins at 1100rpm without doing it, then as soon as the revs dropped it clicked again. I'm thinking maybe the alternator is being asked to send more voltage to recover the revs and its a switch or something making the sound?? :S

Might see if I can get an auto elec to have a look at it and see if they can pin point where it is. Its hard to pinpoint the location with the inlet in the way and the clutch fan blowing air around.

[LANDSCRIBBLE]

check your VCT solonoid isnt spazzing out.

unplug the connector going onto the solonoid, see if it stops hunting and clicking.

feel it with your finger or put a screwdriver tip on it and your ear on the handle

[SargeRX8]

The screw driver to the ear is a really good method at pinpointing sound.