Carbon Solenoid

[bro67]

can anyone please tell me what the carbon solenoid is for in the engine i have a 1997 a4 saloon
found a part number
058 133 517 sagem
it makes a racket as if its working over time

[Randomjim]

Im not 100% but i think its a canister with a valve in that reduces exhaust emissions.

[volcanoblack]

I have seen web sites that refer to a carbon solenoid, but I think the correct term for this is carbon canister. I know the older 5 cylinder turbo motors had these on the rubber intake on the top of the engine and they looked sort of like an inline fuel filter. I seem to recall seeing complaints of them making a racket in other forums. Here's a description of how the canisters work:

Fuel vapors from the fuel tank are vented to the carbon canister.
When the engine is warm and above idle speed, the vapors will be
drawn into the intake manifold via the carbon canister.

Depending on engine load and oxygen sensor signal, a frequency valve
will regulate the quantity of vapors entering the intake manifold from
the carbon canister.

+++++

Hope this helps. Seems like the frequency valve would be more the culprit of making noise, just from the name. I don't have any first hand knowledge if we even have them on the A4 although I think all cars made today have some fuel tank vapor recirculating system. Anyone else remember a previous post on this?

VB

[bro67]

when the car is first started or idleing there is a smell of petrol any ideas on what might be causing this