[Che]

The car is hating these cold mornings, long gone are the days when it starts with first twist of the key.

I was a bit alarmed this morning - a freaking awful noise sounded like it was coming from the passenger footwell - I thought it was the speedo cable, but I was doing zero kph. BTW the noise disappeared 5 mins later when it was warm.

Does the speedo cable have an RPM cable inside also? I only saw the speedo winder part when I had it disconnected

[swifty_ano]

Care to describe the noise?
Car?

[Che]

Sounded like an arc'ing mig welder but nowhere near as loud. Car is a 1990 Sierra running straight LPG. Noise was definitely coming from passenger footwell, not the engine bay or underside.

[mrw82]

cold mornings eh.... you didn't happen to have the heater fan on did you?

[Ben_Sierra]

If the car isn't moving then its either something in the engine bay, or the input side of the gearbox. If it was gearbox then it should stop when you put your foot on the clutch...

Theres no "rpm cable". The tacho works on pulses from the ignition coil.

[Che]

I'm baffled, just had a good poke around and nothing seems suspicious around where the noise was coming from and underneath too. I'm guessing it's cold weather related so i'll have to wait until my next 4am start to hear it again.

It's definitely coming from a more central position, not the engine bay. And was louder inside than out when I tried to pin point it this morning.

Stumped

[ajsr]

something in your heater fan, would be my bet

[Jester]

ajsr wrote:

something in your heater fan, would be my bet

x2

[alien]

yeah either something in the heater fan orrrrr has your oil cap come off the engine and been caught in the extractors and rattling around, then fell on the road? lol

i had mine do this, except the cap stayed in the pipes - luckily the plume of smoke coming out of the engine bay from oil landing on hot pipes made me pull over quick smart before it had a chance to fall onto the road.

but it made a bzzzzzt noise as it vibrated in the pipes =)

[MrRocky]

starter ?

[TZAR]

Angry squirrel???

[hooki]

MrRocky wrote:

starter ?

x2

[atari4x4]

TZAR wrote:

Angry squirrel???

x2

[Che]

atari4x4 wrote:

TZAR wrote:

Angry squirrel???

x2

I put a slice of bread in the footwell, just incase

[hutch]

catalytic converter may have shat itself.

[steve]

yeah, exhaust is under the passenger side.

[Che]

OK, thought it'd never catch it on camera, but I lucked out this morning (luck? ) The only thing i've done is flick the ignition to 'acc'

[flash width=480 height=385]http://www.youtube-nocookie.com/v/4cohmQMIYO8.swf[/flash]

[royce]

Heater fan

[joel]

exposed wire earthing out?
screaming banshee?
was the heater fan on?
thermo fan?
sounds like something simple and doesn't sound extremely serious.

[Che]

royce wrote:

Heater fan

Even if the heater fan isn't on?

[royce]

are you sure its not on if it does it again wind it up to full and back again

otherwise it might be stereo motorboating but it looks off and they dont really do that anymore

[hutch]

wow that is a strange one!
Up under the dash on the passenger side is a modual about 4 inchs long and 3 inches wide. It has something to do with the engine polution control AFAIK. Perhaps it is that. Buggered if there is any wiring in the passenger foot well?
Is the handbrake switch earthing out? Its about the closest to the footwell.

[jonno_racing]

thats weird.. i have a kind of like that noise that comes and goes behind my dash.. but in a different spot... mine sounds like a relay clicking on and off rly fast.....

[hutch]

jonno_racing wrote:

thats weird.. i have a kind of like that noise that comes and goes behind my dash.. but in a different spot... mine sounds like a relay clicking on and off rly fast.....

sounds mightly like a relay to me too... where are your headlight realays

[hutch]

che_guitarra wrote:

OK, thought it'd never catch it on camera, but I lucked out this morning (luck? ) The only thing i've done is flick the ignition to 'acc'

according to the vid at start you at the ON position not the ACC

[Che]

Yeah, not the heater - it's definitely off. Headlight relay is under the bonnet. Sorry, by 'acc' I mean key is fully turned but not far enough to crank the starter.


I was thinking earlier - it's only happening on the coldest of mornings, maybe the LPG fuel line is half frozen, and this is the noise being made when pressure is trying to work through the line?

Definitely sounds louder inside though

[royce]

gas wont flow if the engine isnt running

[hutch]

royce wrote:

gas wont flow if the engine isnt running

so is a resovior up near the engine? Or does it start on petrol then switch over?

[Che]

100% LPG. No petrol at all.

There's a safety shut-off valve at the LPG tank, and there's a bigger shut off valve right before the regulator.

I think turning the ignition opens the LPG tank valve (you can hear this distinctive click when you turn the key) and builds the pressure to the valve at the regulator, and when you crank key to the starter position it opens the second valve so that the motor can be fed.

I think the line in between the valves could be freezing up with a fresh burst of pressure (+ cold morning), but I could be completely wrong. Might explain the extremely hard starting on cold mornings too.

[shep]

i would just pretend that there is no noise and if something stops working then you will
know what it is. if it never goes away and everything still works then ya didn't waste any time on something that doesn't matter.