98’C280 V6: Ticking vacuum/air valve solenoid? P#0004701593
 

98’C280 V6: Ticking transmission vacuum regulator solenoid?

It’s been ticking for a while, and the noise comes and goes. The part number is; 0004701593 and I know it’s a solenoid (two wires to operate it) valve with two ports for air to enter and to exit. It is attached to the left, in front of the fender, near the power steering pump. It has the word 'MOT' in white on the top with a clear silicon plug over some adjusting screw I'm guessing. One of the line ends go to near the throttle body and into a tube to the intake (so then I assume it controls the flow of engine vacuum to something). When there is no power to it (out of car), the solenoid valve is close, allowing no air to pass through it (the tubes). I believe the other end goes to the transmission (but this is not confirmed). I called the dealer parts, he didn’t know what it was for, just that it was a valve. Anyway, anyone know exactly what part this does and the possible consequences of driving the car with it clicking (meaning it is not staying open)?

Any info would be greatly appreciated
Thanks,
MarkC

I think you're talking about the Canister Purge Valve.
It's supposed to tick.
When the engine is running , it opens/closes very rapidly, sucks gasoline fumes out of the gastank & burns them in the engine.
This explanation is a " simplified " version of what it does.;)

Thanks Manny, :) that sounds right. There is an arrow on the valve which points in the direction of the flow of air (exit from valve), and the outlet/pipe it points too goes to the area near the throttle body. At least the ticking let's you know it's working, but is it normal for it to tick fairly loud, louder than the engine noises?
MarkC

They can be quite loud.
Possibly even more so in colder weather.
Don't worry about it. ;)

Ok, thanks for your help Manny.:)
MarkC