Radiator cap? coolant leak

Originally Posted by Darwins Child

Therefore, because the hose and tank are pressurized, and one of the two small OEM clamps has already leaked, I used the second SS worm clamp in the 2-pack to replace the other small OEM clamp on the same hose where it attaches to the tank. (The second small clamp was considerably tighter than the first, but I replaced it anyway.)

Just out of curiosity, I checked our '10 Mit. Outlander which has 106,000 km (versus 9,500 km on the Z) and it has the same type of larger hose clamps and they've never failed, so I'll accept the same risk on the Z's larger clamps holding. Knock on wood.

For the $180+ cost of Nissan's pre-purhcase inspection, the tech should have diagnosed that leakage correctly (if it does indeed turn out to be the hose clamp that was leaking, which at this point I'm 90% certain of). The tech stating with certainty that it was the cap that was leaking (almost certainly without doing a pressure test) was not only just plain wrong, it sent me down diagnostic paths that I would not normally have taken-- for example, starting this thread because I assumed that the tech was correct and that the new replacement cap must still somehow be the problem; and just exactly WHAT could the problem be with the new cap or the part it seals against, etc, as I detailed in my first and ensuing comments.

If I had discovered those signs of leakage myself, without the input from an "expert", I would have replaced the clamp first thing, monitored the result, and not bothered this forum, let alone a stealership, with something so trivial.

This experience once again reinforces my long-held policy to take what "experts" in various professions -- from health to finance to politics to automotive -- only as advice, and with a very big, very skeptical grain of salt. In this case, even though I have never had to replace a radiator cap on any vehicle I've ever owned, because the Z has what to me is an unusual cooling system arrangement, I assumed that the tech actually knew what he was talking about when it comes to the Z.

Thanks for all the help, guys. I appreciate it.

BTW, I did not forget to re-install the cap on the tank before I closed the hood (for the second time), but I must admit that posting this latest photo was indeed a helpful reminder.