960 1996: Noise from a unit in Engine

[Volvo2009]

With ignition key is in, on stage II, (power to accessories in on, and no engine running). I hear screeching noise coming from this unit. It mostly occurs when engine is worm. Have no idea what is it.

Also, I suspect air leaks into my steering wheel's oil canister (air bubbles appear in the fluid when engine is cold, and disappear when hot).

[billofdurham]

That is the carbon canister which is part of the fuel evaporative system. Evaporative emissions are the result of petrol vapours escaping from the vehicle's fuel system. Vehicles now have fully sealed fuel systems that do not vent directly to the atmosphere. In a typical system, vapours from the fuel tank are ducted to canisters containing activated carbon. The vapours are adsorbed within the canister and, during certain engine operational modes fresh air is drawn through the canister, pulling the vapour into the engine, where it is burned.

I have never heard one screech and without the engine running it shouldn't be venting to the engine. Check all of the pipes, especially those made of rubber, for leaks as it may be pulling air in.

Are you losing fluid from the power steering? Air coming in should equal fluid going out.

It may be that the system needs bleeding.
Jack up the car so both front wheels are clear of the ground.
Ensure fluid is up to level.
Start the engine and allow it to idle.
Turn the steering wheel from lock to lock in a slow, even motion which lets the pump operate at low pressure.
Watch for air bubbles. When they stop the system should be air free.

Bill.

[Volvo2009]

Bill,
thanks for the reply.
In regards to the steering wheel, I have suspected an air leak lurching somewhere. I already replaced the fluid in the reservoir with a similar fluid with sealant content. It should take care of the leakage.

In regards to the carbon canister, I had no idea what this part was for. Thanks for the education though. I certainly will check all the hoses to that unit.