High pitch squeal in engine bay

[ephect]

Hi crew.

Need some help with this one. Pulled up to a set of lights and heard a squeal, faint but there. Took off and it disappears, until stopped again. Noticed this a couple more times before parking at work.

Started it to drive home and it's quiet until halfway and it started squealing again. Pulled up at home, popped the bonnet and it was loud to the point it pissed our dog off.

After a bit of research, likely fault pointed to bad rectifier diodes. Swapped out the alternator for a spare I had and swapped the regs.

Started and no squeal, after a strap is back again. need to swap the reg over as a final check. It's not bearing noise, as I've dealt with that sound, plus the squeal drops off/fades out when killing the power.

So it's only present when the engine is hot. the main power cable is ok, not great and under load I'm losing .4v

Hard to pinpoint but it almost sounds like it's coming from the purge solenoid.

I've got a video I just need to shrink before I can upload.

TL : DR help me with an squeal in the engine bay.

 

[ephect]

Video

 

[greenacc]

That's a strange one. Ecotec squeal is usually an idler pulley bearing so check that out but your noise sounds a bit different.

 

[two-bit]

that's sounds like a solenoid squealing to me, disconnect power to purge solenoid see if it plays up agan

 

[ephect]

Haven't gone anywhere yet to warm it up. Currently in the garage with a leaky tyre.

Hopefully tomorrow I'll drop the spare on and drag it out side and check if unplugging the solenoid kills the noise.

Let's see what happens with this lockdown

 

[greenacc]

Ah a Victorian. My condolences!
I can't believe Lieutenant Dan still has his job. Quarantine has been a disaster, not much different in NSW either really

 

[ephect]

Thanks mate. Yea it's been long enough now. You'd think they'd have this down pat, but let's not over react and lock the whole state.

I guess on the bright side, there's nowhere to go so I've been working on a few outstanding issues on the car.

 

[Drawnnite]

I feel your pain Ephect (in the same position).
But it does mean forcing you to be at home to do all those things you often put off.

Definitely an Electrical sound. If it was mechanical it would most likely change with revs?
I assume the purge solenoid only operates once its warm, or is it in an area that gets warm and can be effected by the heat?
Reminded me of so many processing plants with that electrical "hum".

 

[ephect]

I haven't actually checked when the solenoid kicks in so I'll read manual see if there's some pointers.

It's at the back of the drivers side head so really only trans and booster, no real extra heart apart from the headers

 

[greenacc]

Thanks mate. Yea it's been long enough now. You'd think they'd have this down pat, but let's not over react and lock the whole state.

I guess on the bright side, there's nowhere to go so I've been working on a few outstanding issues on the car.

Yes it's a good opportunity to get things done. It's just the psychological impact of being locked down makes a lot of people just sit on the couch and feel sad LoL