So my engine is shaking

[Derpy]

So my engine is shaking at idle but goes away at higher revs or when i have the ac on, also my rpm needle is bouncing on a cold start(engine revs going up and down also). My belt tentioner is bouncing and it looks like my harmonic balancer is slightly moving left to right (Not towards and away from the motor, seems secure) dont know if thats because of uneven power.

New coils
new sparkplugs
new fuel filter
new oil (every 7000km with oil filter)
cleaned fuel injectors
New vacume hose
New intake manifold gasket
Cleaned maf
cleaned throttle body
new water pump

Going to test compression and fuel pressure in the next couple of weeks
Should I replace the harmonic ballancer or tentioner if they come back normal because I've checked for vacume leaks and can't find any

 

[greenacc]

Was it shaking before all those parts were replaced?
Have you tried to work out if one cylinder is not firing and which cylinder that is? Sometimes you get a faulty coil in a new set especially if they're no name items bought online. I had one fail after about a week. When the harmonic balancer fails you can often see rubber coming out of the joint.

 

[stick3]

have you done the pcv mod https://forums.justcommodores.com.au/threads/alloytec-pcv-problem-fix.279039/

 

[Derpy]

Yeah I've done the pvc mod, I've also tried unplugging each coil to see if the rpm doesn't changed but each one I unplugged I noticed a rougher idle, and yeah the rubber is pushing out on the harmonic ballancer, I'm checking the compression because of some lack of power and fuel pressure, thanks greenacc I'm pretty sure that's the issue

 

[wannaeatyourbrains]

What about your engine mounts? Screwed harmonic balancer and old mounts are a likely combo. Wait till you pull that balancer off. It is often bulging out the front, and then you find a whole section torn out at the back of the bulge.

The Mace harmonic balancer has treated me really well. Original GM not so good.

Do you drive fast? Maybe your engine only shakes when you approach.

 

[Derpy]

I think it would be a good idea to change the engine mounts at this point too, yeah was going to get a

Powerbond Harmonic Balancer - HB1177-N

From repco bit steep but I'd rather replace it once, anyone know where I can get a new bolt in Melbourne area?

 

[gungazza]

Holden

 

[wannaeatyourbrains]

I am reminded of the rhyme.

Algy met a bear.
The bear met Algy.
The bear was bulgy.
Algy was the bulge.

 

[lout]

I am reminded of the rhyme.

Algy met a bear.
The bear met Algy.
The bear was bulgy.
Algy was the bulge.

might be time to open the garage door
i think the fumes may be affecting you

 

[vombil]

Yeah I've done the pvc mod, I've also tried unplugging each coil to see if the rpm doesn't changed but each one I unplugged I noticed a rougher idle, and yeah the rubber is pushing out on the harmonic ballancer, I'm checking the compression because of some lack of power and fuel pressure, thanks greenacc I'm pretty sure that's the issue

Did you find the issue mate? Mine shakes without a/c on (its an RPM thing that must iron out the lump/shakes) I have chain noise too though and the wrecker told me its about to let go which is causing the shaking - ie a timing issue due to sloppy chain