MikeC (Pgh)

Driving around in my new 2.7T over the extended holiday and the check engine light comes on. Take it to the dealer and they say that it has a defective "Evaporative Canister Valve" and that they'll order the parts. I asked, and they said it was okay to drive around even though the parts may be on order for months. Does anyone know if this is a good idea? And also, what the heck does this part do??

Chris B

When I first picked up my 2.7T the a/c did not work. The dealer called the defective part the "dryer" in the a/c system. It would help evaporate water in the system. Does you your a/c work?

JOB

vapors/fumes are drawn off your gas tank (so that they don't escape/evaporate into the atmosphere and pollute the air). The "valve" your dealer refers to is likely a valve connecting this canister to the engine intake manifold so that the engine can draw in (and burn) these (filtered) fumes. As long as your engine runs OK (and esp. idles OK), it's probably OK to delay replacement of this valve, as your dealer suggests.

This is all my educated guess from having seen this sort of canister on almost all cars for years now, as a fairly standard component of the car's overall emissions control package. (I've yet to inspect my own 2.7t for this particular canister but expect that it has one as described above.)

Cheers,
JOB

MikeC

When I took delivery, the A/C was working fine but since it's been pretty cold here recently, I didn't check it after the MIL light came on. Seems like JOB may be on to something with his explanation so I'll probably just ride it out until I get the parts some time in 2001...

JOB

sounds like the "Receiver/Dryer". A/C's often have one of these in the high-pressure (liquid) part of the system just upstream of the juncture with the low-pressure (gas) part of the system. Purpose of reciever/dryer is to receiver/accumulate liquid freon and remove any water from it. Physically, the Reciever/Dryer is usually a smallish, sturdy steel/aluminum container capable of withstanding more than 300 psi pressure. It may have a sight glass on it where liquid freon flow can be observed (for possible air bubbles, etc). It's generally replaced with a new unit whenever the A/C system is opened to the atmosphere during major repair work because the special moisture-collecting desicant material inside becomes ineffective at collecting further water/moisture after a while. And, water/moisture circulating in an A/C system leads quickly to its demise.

Apparently, one of the connections to this Receiver/Dryer or the Receiver/Dryer canister itself was leaking on Chris B's car, causing his A/C system to leak all/some of it's freon charge. Hence the poor A/C cooling.

MichaelC

Called up the dealership today to find out exactly what this "evaporative canister valve" is and they say that it has to do with the A/C system so I guess Chris B might be right after all... Well, good thing it's 30 degrees out or I might really be complaining.

Thanks for the info.

Michael