Wtf Is This Weird Noise?

[soultz]

took my car for a drive tonight after i changed coil packs, my missfire was so close to being fixed just a little tiny missfire, anyway i turned the car off and looked under the bonnet, i could hear a noise which was coming from the coil pack/injector reigion (top of engine) like a crackle???? or a crinch if you will.....it sounded like the injector was clogged or still pulsing even tohugh the car was off???

is this normal? or is this even the problem? i dont know where the noise came from exactly, but it was every 2 seconds and constant....

[soultz]

http://soundcloud.com/matt3429/voice-001 listen to it, its not the crackle every 2 or so secs its the sound behind it, sounds like a chewing sound ??

[t_revz]

Sounds wierd like a midget banging on a milo tin while someone else is eating with their mouth open. Maybe spark plug isn't sealing completely and air is escaping.

[SargeRX8]

The midget with the milo tin is normal, its just metal components losing heat and cooling down. The other sound is a strange sound, if I had to take a wild guess I'd say some sort of liquid dripping onto something hot and evapourating.

If there was air escaping from a pressurised cylinder, it should be more consistant.

That is a really odd sound, it doesn't sound electrical, mechanical, metallic.

[ANT_32]

I have this sound! Its air bubbles in a coolant hose somewhere. From your turbo or heater probably like mine. Im still not sure what is rooted though ha ha but been driving it for a few weeks and nothing hapened yet. Maybe a slightly rooted Head gasket ?

[SargeRX8]

Have you tried bleeding the coolant? Do the bubbles come back? If you get bubbly coolant after bleeding it properly chances are your head gasket is gone.

[GTR-N1]

Use a wooden dowel between 30-60cm long approx > one end in your ear + the other placed on various parts of the block > sound becomes crystal clear when in close proximity.

(Using a long screwdriver is a bit less accurate)

[adamskill]

Use a wooden dowel between 30-60cm long approx > one end in your ear + the other placed on various parts of the block > sound becomes crystal clear when in close proximity.

(Using a long screwdriver is a bit less accurate)

well I'll be damned!

[soultz]

ive had the car for half a year now and it only done it the first time the other night, hasnt happened prior or since the other night, it was 1 one off??

i was flogging the car that night, got it to 180Klms, and when i turned it off that sound happened, so could me flogging it have something to do with it??

[ANT_32]

I reckon head gasket.

I bleeded mine twice so I know it's more than just air in the system.

[soultz]

and how does one go about changing head gasket?

[StevenCJR31]

and how does one go about changing head gasket?

with the correct tools and good knowledge of the task at hand, not a job for a novice as you can f@#k things up if its not done correctly

[DVS JEZ]

Do not replace the headgasket until some diagnostic tests prove that is an issue.

See if it does it again ever, but otherwise i would say its just the turbo and metal exhaust components cooling down as sarge suggested

[Hanaldo]

I have this sound! Its air bubbles in a coolant hose somewhere. From your turbo or heater probably like mine. Im still not sure what is rooted though ha ha but been driving it for a few weeks and nothing hapened yet. Maybe a slightly rooted Head gasket ?

It doesn't sound like bubbles to me, how did you come to that conclusion?? Genuinely interested, not being a jerk.

Edited May 2, 2012 by Hanaldo

[ANT_32]

It doesn't sound like bubbles to me, how did you come to that conclusion?? Genuinely interested, not being a jerk.

Well the on a turbo hose you put your hand on it (with a rag obviously) and you can feel it sort of vibrating as the bubbles are going past.

Also when radiator cap is opened while the noise is happening it will spit and fart at you. However it is almost as though the water is boiling as it does not use any water or over heat.

Been driving it for over 5000km like this now and nothing has happened yet.

Edited May 7, 2012 by ANT_32

[89CAL]

Is there coolant in the radiator or just water.......?

[ANT_32]

Is there coolant in the radiator or just water.......?

Coolant is at 40%

I will do a leak down test later in the week. Hopefully it might show something.

[D.I.Y. Mik]

That sounds like something boiling for sure, theres a restriction which opens at a certain pressure and it builds up then lets go repeatedly.

If thats the case it should gradually slow down as the engine cools.

Ive heard that sound somewhere before, cant remember.

[ANT_32]

Well I'm guessing there is a blockage in the turbo line then. So when the motor is turned off and has no flow the coolant in the turbo boils.

Been studying a bit and found coolant boils at about 240 ish degrees give or take with pressure etc.

Turbos get hotter than that.

So it would be possible especially if you was giving it heaps before turning off I reckon.

[DVS JEZ]

Is the 240degree boiling temp under pressure?