The rubber on the early ones was not pliable so the sound got transferred..that is why I said to dis-mount it when it is ticking..I think that yours is the newer one anyway.
The wd trick is to squirt it into the valve by taking the line off while it is operating .. if it is dirty [causing the noise], it will suck the debries through.
If that works, let it go..if not , buy a new one ..you can install it in 2 min.
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