tapping. purge valve? where?

[timmyj51]

Light, rapid, tapping coming from my engine bay in sync with the
engine though don't think it's coming from the engine. Did
a search of this forum and might be the purge valve. Where
exactly is this located? Haynes manual says its on the
bulkhead. Not much help.

[xvvvz]

On a C230, if you are standing in front of the car it is on the right side in the area near the washer fluid resevoir.

[benzonline]

Isnt it normal for it to tap? Mine taps when the engine is fully warmed up.

[timmyj51]

Found the purge valve. Pretty sure this is where the tapping's (more like a
fast, loud, clicking) coming from since I can feel the vibrations/pulsations
when I put my finger on it. Can I just ignore it or will it result in some
performance problem/malfunction or trip off the check engine
light? Stealership wants $150 for the part. It never
made this noise in the past, benzonline, so I
certainly don't think it's normal.

[audiophile]

what's the purpose of it?

[Pagz]

A new solinoid will make the same tapping noise.
the solinoid regulates the amount of fuel vapour that is drawn from the tank through a charcoal canister into the intake plenum...it is a form of emmission control.

you could try minimise the noise by making a baffle over the solinoid of prehaps a softer mount...just an idea.

[shandy]

Possible reason for your purge valve being noisy is that the charcoal canister is due for replacement .

[timmyj51]

How so? Canister just absorbs gas fumes.

[shandy]

The canister is a service item and is supposed to be replaced every 30,000 mls or 2 years. In common with all filters it will continue to function with decreasing efficiency well past it's service life but the core will eventually clog and/or collapse thus restricting the flow and the EVAP valve will make audible clicks as it tries to purge the cannister.
In actual fact these canisters are seldom changed but if the EVAP/purge valve begins to click audibly this is one thing you should not discount.

[benzonline]

Are you sure? If I we dont change them what would happen and how much to change?

[timmyj51]

My question exactly. Can only get replacement canisters from
stealeship...$140! Don't want to replace one unless I'm sure
that'll solve the purge valve noise. I take it you can inspect the canisters? What
are the tell-tale signs they need to be replaced? Any test you
can run to make certain the problem's with the canister, not
the purge valve?

[Pagz]

if an increase in vaccum does affect the noise level of the solinoid i would be very suprised,but if this is the case you may need to replace the canister.

a few years back i did go to the stealership for this exact problem,but was told a new solinoid will sound the same and that its a commen issue.