Upper Radiator Hose

As the break-in miles concluded, I was nearly home when the temp gauge climbed quickly. I pulled over, let the engine cool down, then started off again until it climbed. This process was repeated until I was safely in my driveway. Thankfully I caught this in time to not destroy the motor with a catastrophic overheat. But I didn't know this for sure until I investigated further.

 

This massive puddle (covered with cat litter) was coolant that leaked out while it sat. I couldn't see any obvious problems with the cooling system. And the exhaust didn't smell like antifreeze. I let the engine heat up after my first post-break-in oil change, and still saw lots of steam coming off the engine. More than you'd expect.

After looking everything over, and not finding much, I gave the upper radiator hose a squeeze and a nice spray hit the alternator. Closer inspection revealed that the alternator pulley had worn a hole in the hose. Which was annoying but a massive relief. I was aware that the upper hose hitting the cooling fan was a problem, and the hose I had included a sleeve for that area, but not the alternator.

My guess is that the aftermarket radiator, being much thicker, put the OEM-style hose too close. It didn't touch when sitting, but must have enough movement when driving to eat through. It took 1000 miles almost on the nose.

At any rate, replacing the hose and refilling the coolant made the car much happier.