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Old 01-15-2010, 09:27 PM
Supercourse Supercourse is offline
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Location: British Columbia, Canada
Join Date: Feb 2008
Posts: 3,890
Mein Auto: 2004 X3 2.5i
Originally Posted by fantrider View Post
.... I found clear fluid in the fitting, my guess is water. Is that what has potentially ruined my valve??
I think the sequence is:

- valve gets stuck in the open or partly open position instead of closing after 90 secs. or so
- exhaust gases (containing water vapor) get through valve on permanent basis
- water gets into pump which is in no way corrosion resistant
- pump starts to rust
- clanking sounds may be heard while pump is in operation
- pump eventually disintegrates

So you are doing the right thing by verifying that the valve is not doing its job, and planning to replace it before the pump is compromised.

How much water you found may be important, as any CEL does not necessarily mean that something needs to be replaced.
It could be that some water is condensed during the 90 sec. normal operation of the valve.
Not sure on that.

Maybe the revised valve is meant to avoid the sticking problem.
At least in the X3, the valve and pump look to be more protected from the elements than in some other BMW models.
Tucking it in behind the windshield washer tank might be only a packaging decision,
but it is much more accessible for servicing than, say, the CVV on the other side of the engine.
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