POP goes the coolant pipe!

During a spirited afternoon of driving, my 2008 Cayman S Sport puffed a nice cloud of coolant out the rear and left a trail until pulled over. (To my knowledge, no warning or over-temp lights came on, so hopefully engine damage is minimal/null.) I got it home, pulled the underbody panels, and pretty quickly located a drip from the coolant pipe assembly. It would seem that after so many heat cycles, this clamshell seam gave up the ghost. Sounds like I have a real hassle of a DIY ahead of me. Anywho, perhaps this is more of a minor PSA to give this a quick once-over the next time you're down there.

Ouch. Hope its a quick fix with no other issues resulting!

@rounders -- Boo!!! Hiss!!! (pun partially intended). Sorry to hear it. WAG is that it won't be horrible, but I couldn't say for sure. If you've already done your coolant pump, you probably know how to do a vacuum fill and the like. It sure looks like you've found the leak, but UV dye is a huge help with narrow stuff down. Also, remember that our 98X cars have a TON of hoses to get the coolant to the middle of the car, which means that there's a huge coolant reserve. Odds are, you didn't lose that much and didn't do any damage to the engine. You would have had a low coolant sensor go off first and then your temp would have spiked. I think you're just fine in that department. Let us know how you get on there with the repair. Cheers.

Interestingly, another user had the same issue, also right after doing preventative water pump work. Maybe just coincidence. Edit: having a tough time posting some helpful links. I’ll have to try again later.

I was planning on replacing the water pump proactively on mine this spring, and was on the fence on replacing all the hoses from the engine to the pipes that run forward. You've convinced me to replace them all while doing the water pump. Hope your swap goes well.

As foodbiker says, the use of an AirLift or equivalent is highly recommended, really makes the coolant refill much easier.

@Wizco I’ll say that I’m not seeing any issues with the aluminum pipes, or even rubber hoses, only the plastic coolant “pipe”, but if you Auto-X like your profile picture suggests, that sounds smart to me. @racergreg I’ve used the OEMTOOLS 24444 tool with success as well. I did it with a 3 gallon hot dog compressor - bigger would have been easier.

Anything plastic/rubber subject to heat and is 17 years old (for me) is subject to breaking/leaking when moved/touched/adjusted. I replaced the AOS a little while back and all the plastic piping to and from was collateral damage. Fortunately I wasn't on the fence on that one, and had the spare piping on hand.

Would anyone happen to know if the fasteners holding the coolant pipe on are torque-to-yield? FCP Euro shows them in a kit, which suggested they warrant replacement, but the fasteners are special order (longer lead) and somewhat pricey. I’m now questioning whether they’re necessary to replace. P/N POR-99907335201 qty (5) P/N VAG-N10124306 qty (3)

The coolant cross-over pipe is one of the parts I recommended changing during preventative water pump replacement! It should be an easy fix if you have some DIY abilities. If you have a manual car that you drive hard or take to HPDE in warm climates, I'd add the third radiator as well. Happy wrenching!

Most aluminum fasteners should be replaced after each use. Even if not torque-to-yield.

Finished the swap - overall, not bad. I only cribbed the rear wheels, but should have done the front too for extra clearance. The “infamous” 5th torx bolt is a piece of cake if you remove coolant hoses and drop the carrier. The worst part was the firewall insulation sprinkling down onto my face while removing the (9) T30s that hold the pipe on. And to @Wizco’s point, I found that one of the engine carrier studs was eating into my coolant hose. I’ve opted to replace those.