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Does this look like a failing expansion tank cap? My part # is 996-106-447-01 and Pelican shows 996-106-447-04-M100 - which I assume is a revised and newer part - based on the 04 at the end. I have cleaned it up to see if there is a leak, but for the $30, maybe it just makes sense to replace. Query - Would this kind of failure cause operating temperatures to be higher than normal?
Replace the coolant expansion tank
You can purchase a genuine "04" for under $15.00, no tax, free shipping from here: Porsche 911 Boxster Cayman Expansion Tank Cap FEBI BILSTEIN New 99610644704 | eBay I replace mine every year as part of preventative maintenance; I don't even test the existing one. I've heard of water pump failures because of old, faulty caps, so I don't even mess with them. It may be an old wives tale, but then again, I haven't replaced a water pump yet. Just sayin'............... TO
Replace the coolant tank cap
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