[Rossco]

Turned on the sierra today and it has developed a ticking sound when the engine is running under the passenger side dash. The ticking sounds a bit like injectors or maybe a leaf in the blower but it is neither and cannot be heard in the engine bay. Its affected by revs, (it is evident through the range) it goes up in volume slightly and frequency. It was going through my external speakers for the UHF which are mounted just under the dash. I have unplugged these, the aerial, and the radio and the noise is still there. I have a G16B conversion and the computer is mounted under the dash. I just pulled it out and the noise is not coming from the computer nor any of the solenoids around it.
I'm assuming if it was going through the speakers it would be electrical related, maybe tape that has come off a wire somewhere? Any ideas?

Rossco

[Rossco]

Ok I figured out what was making the noise. its the the ignitor/coil assembly that is screwed into the fire wall. I have run a ground strap to the fire wall and there is no ticking as long as the assembly is not touching the fire wall. This has never happened before so not sure why it has just started. the coil was replaced three months ago, time for a new ignitor?

[mike.knew]

A trick that has served me well in the past is have a look under the bonnet when it pitch black at night. After your eyes adjust (and this may take minutes) you might be able to see exactly where it's arcing out. I've had something similar on a datto I had years ago and it's was a cracked insulator on a spade terminal. Bit of 'lecty tape and all good

[Rossco]

righto good thinking ill have a look tonight. It has been hot so maybe something melted.

[Rossco]

Nope no arcing around the bracket, any other ideas? I'll try a strip of neoprene between the bracket and firewall tomorrow maybe this will insulate any kind of noise transmission.

[tonyevans]

DO NOT put anything under the igniter except heat-sink grease as it dissipates heat via the joint between the back of the igniter case and the bracket.

True fact..... True fact..... True fact..... True fact.....

[Ace]

A cheap way to isolate the source of the noise is around 3ft of garden hose attached at at one end to your ear, also night eyes is a great way to source elecky arcs.


If all goes wrong try a workshop manual and a multi meter... then there's no arguments