vz sv6 sounds like tractor, vibrates in idle..

[kicker12]

Hi all, this problem has been going on for a while now but since I've finally booked it in to get it checked out i've become more and more curious. I've searched everywhere on these forums, the internet, google, and nothing.

When i turn my car on, it's fine....sounds and runs like normal, then after the engine warms up a bit and the revs drop (eg when im pulling up at a set of lights) often the engine will start to sound like tractor and the noise fluctuates sometimes going louder then softer...it's a pretty bad sound.
In addition to this, often while idle and making the noise the engine will shudder and you can definitely feel it form within the car.

However as soon as you rev the engine a bit the noise and shuddering completely goes away as if nothing was ever wrong, and on the rare occasion when i rev it at the lights and the revs drop back to idle the noise stops even in idle.....but then if i rev it again and drop the revs back to idle after the whole problem comes back.

I've been searching around the internet and thought it might be an engine mount, something might be loose on the engine causing the noise, something may be blocked like an air valve or i don't really know.

And yesterday for the first time my car just cut out at the lights, after taking it for a short drive (i've only been driving it on short runs over the last few months maybe like 1 every week or two just to keep everything ticking over).

So anyway i've booked it in at the mechanic but thats for 2 weeks time and was wondering if anyone here possibly has an idea of what it could be....

Cheers guys

[bigdaddycool]

Pot guess here.... but i heard the vz sv6's have an issue with their powerchain cause of the variable exhaust camshafts (often rattle and carry on)...... maybe it'll have something to do with that.

but yeh take it to someone, see what they say.

[STRIKE]

Wheres the sound coming from? It sounds like you have a heat shield loose thats rattling away.

[neet_wagon]

.....................I know nothing apparently

[kicker12]

thanks for the responses guys, i know i shouldn't be driving it, it's been off the road for about 2-3 months now just saving to get it fixed and doing a few things to the interior i've wanted to do for a while. i've driven it probably maximum 30km in the last 3 months.

haven't really managed to find much on the timing belt issue...i'll post up a video of the noise soon and see if anyones heard it before

[andyman]

considering the alloytec dosnt have a timing belt id rule that out, there was a few isolated makes that had a defective timing chain that strectched, if it was the chain it would rattle all the time,

if its making the car shuddder as rattle wont do that, id suspect a coil breaking down causing and ignition fault

[Corbs1234]

i did have this after my first service on my ute. the mechanic didnt properly re-attach the spark plug leads. it'd idle like it had a cam for a bit, then the revs would increase as if the aircon had been switched on. then it would go back to a lumpy idle.
but the stalling at the lights is strange...
is it a metallic sound when vibrating though?

[impulsive]

considering the alloytec dosnt have a timing belt id rule that out, there was a few isolated makes that had a defective timing chain that strectched, if it was the chain it would rattle all the time,

if its making the car shuddder as rattle wont do that, id suspect a coil breaking down causing and ignition fault

maybe this has caused the bolt to come loose on my cam, causing the current problem. Do you think?

[andyman]

maybe this has caused the bolt to come loose on my cam, causing the current problem. Do you think?

nup youd have a cam out of round, tunnel misalignment, or unlucky enough to have a dodgy head casting

[kicker12]

Ok so i've uploaded a soundclip of the noise onto youtube.

You can hear me fiddling around withe the camera first....then you can hear me get out my keys and turn the car on and it idles...and then i rev it a little bit (engine was warm when i did this a little while ago..took me ages how to work youtube lol) and you can hear the engine drop back to idle and make the tractor sound, its usually not as consistent as that though, like it'll get louder and softer and the engine shudders harder and softer etc. but that only ever happened while i was driving it and i'm not going to go do that anytime soon, but you get the idea.

Anyway, then after the tractor noise you can hear me rev the engine again and it sounds normal while i rev, and sounds normal when it drops back to idle. but if i had revved it again a bit when it drops back to idle it would've made the tractor noise again. Confused yet? lol.
thanks for the responses guys started to get really worried about this now..

YouTube - idle noise.mov

[andyman]

sound as if its pinging, what sort of fuel have you got in it?

[kicker12]

Whats that mean? I usually use 98 premium fuel, rarely anything else

[andyman]

pinging is when the fuel pre ignites before the spark plug fires before top dead centre,

if the fires before t.d.c you get that ping noise, as the flam front creates a shock wave and causes the knock,

id recomend getting to a mechanic as soon as you can, as pinging is really not good for motors,

[kicker12]

i see, well i'm booked in for the mechanic in exactly a week until then im pretty much going to be biting my nails.
i'm not going to lie, i haven't treated this car as well as i should've which is why im left with such a huge repair bill. already spent 1500-2k on fixing brakes, suspension, tires etc. and the last step is fixing the engine. guess i've learnt my lesson, i just hope i haven't pushed it beyond the point of repair.

thanks for your help andyman, you seem to know quite a lot...could running fuel constantly low be a contributing factor to a ping? also there was a period of time where i used 7/11 fuel, i still used their 98, but a mate told me after a while that their fuel was quite poor..i guess it could be a combination of things.

cheers

[andyman]

i see, well i'm booked in for the mechanic in exactly a week until then im pretty much going to be biting my nails.
i'm not going to lie, i haven't treated this car as well as i should've which is why im left with such a huge repair bill. already spent 1500-2k on fixing brakes, suspension, tires etc. and the last step is fixing the engine. guess i've learnt my lesson, i just hope i haven't pushed it beyond the point of repair.

thanks for your help andyman, you seem to know quite a lot...could running fuel constantly low be a contributing factor to a ping? also there was a period of time where i used 7/11 fuel, i still used their 98, but a mate told me after a while that their fuel was quite poor..i guess it could be a combination of things.

cheers

poor fuel with a low octane creates a low ignition point, so that can make it ping, but to many other factors can cause this too, old spark plugs and such

[kicker12]

it's the crankshaft...could be in a lot of trouble here, my mechanic said he called holden and they quoted 10k for a fix...

[ruffiano]

Soooo.. you're just going to crate in a 6L for that money?

[impulsesv6]

99% its not the crank... get a new mechanic... hes lubing you up

[kicker12]

how can you be so sure? if it's not the crank its still probably something as big, he said it's coming from the centre of the engine. and he called holden out of my interest as in, he was calling them to find out how much it would cost if i took it to them (therefore my mechanic would make nothing).

he's taken down details of the engine etc. and researching a few things for me so im pretty sure he's not taking me for a ride. he said the oil that was in it was no good, and having had my car serviced at holden last i have my doubts over their competence rather than my mechanics to be honest..

[impulsive]

its not a crank mate, if it was the pinging would continue and the car would not be very good to drive.. He is pulling your dick so to speak.. Try someone else

[impulsive]

how would he know its the crank unless he has it out? It could be a number of things.. Just experienced a noise similiar to this recently..

[kicker12]

i suppose that's true, he didn't say it was definitely the crankshaft, but whatever it is he said the noise is coming from the centre of the engine, i have to take it back in 2 weeks coz they are booked out until then and then they can properly take a look but they didn't have time to check it any further today as they were expecting it to just be a case of broken leads or something (based off what i told them how the engine was acting).

wait and see i guess, either way the engine really doesn't sound good and its just really weird that at certain times the engine idles like new, then the next second the fornt of the car is shuddering and feeling likes it's about to cut out on me..i dont get it.

thanks for your input guys i don't mean to sound rude when responding to any of you i just...well, im sure you can understand lol this isnt a desired position to be in and i don't feel like getting my hopes up in case they get shot down again and im up for a new engine.

[impulsive]

do you have a garage? Pull the 'rocker' covers off and inspect them.. thats where i found my issues (loose bolt on cam & timing chain tensioner broken)

thats where i would start.. do not drive it, because if it is timing then it will only screw your motor

if he qouted 10k for a new crank shaft he is pulling you off, just get a new motor for 4500

[kicker12]

i see, i don't really feel comfortable with touching the engine, im not bad with electrics, interior, wheels, brakes etc. but when it comes to the engine don't really wanna touch that. and he wasn't quoting me 10k he called holden to describe the problem to them and THEY said it would be a 10k fix, in which he told them to get stuffed. and yeah it's looking like i will end up needing a new motor.

[andyman]

because you cant disconnect the injectors on these while there running, it makes it hard to shut down cylinders,

you could disconnect a coil at a time to see if its a main bearing or gudgeon knock, but disconnecting the coils could cause voltage spikes and could damage the ecm,

best way to do it would be get a scan tool that can do diagnostics, and run a cylinder balance test, it shuts down one cylinder at a time to check engine rpm difference, you could use this to diagnose motor noises