We pulled alongside one of the moored boats and I dove into the engine compartment. Opening the bleeder valve, a rush of steam escaped but then coolant. After a few second, the temperature returned to normal. "Just an air lock," I thought, and off we went. The next section of canal (the section between locks is called a "pound") was about 5 k and I kept a close eye on the temp gauge as we motored along. All seemed to be well. However, just as we pulled into the next lock, the gauge pegged yet again. After another quick visit to the engine, it seemed to be under control and the next pound was only 1.5k. Pegged again as we entered the lock. One more air/steam bleeding operation and we headed for the next lock about 1/2k up the canal. If it happened again, we were done for the day and would have to find a mechanic to look at our problem. Sure enough upon entering the next lock we overheated again. There was a great tie-up just past the lock. We tied up and called back to St. Symphorien. Luckily, Port Captain Peter happened to be standing next to Bourgogne Marines mechanic, Alain, when we called. Peter said Alain had to finish up a little task but would see us in an hour. An hour and a half later (exceptional performance by French standards!) Alain arrived and diagnosed the probable cause as a bad thermostat. He happened to have an exact replacement thermostat for our Mercedes engine in his truck. Unluckily for us, the simple fix didn't work. We would have to return to St. Symphorien for further diagnostics and repairs.
We spent the night at the tie up and turned about to return to Bourgogne Marine Friday morning. After getting a replacement for our "telecommand," the remote control that operates the lock (our first one was malfunctioning, of course!) we finally got underway about 9:30. The engine heated some before the first lock but not too bad. However, after the second 1 1/2 k long pound, we thought the engine might explode from the heat; steam was escaping from everywhere! We made it through the lock into the 5 k long pound but were going to go no further under our own power.
We made a call back to Bourgogne Marine to try to arrange a tow, at least to the next lock, about 5k. If we got that far, we would be able to use the engine to get through the last lock and into Bourgogne Marine's tie-up. The return call wasn't good. Port Captain Peter said there wasn't anybody available to tow us but, to paraphrase, "let me have a bowl of soup and a shower and I'll be up there and we can pull her back down the canal."
"It's not that far," says Peter. "It'll only take an hour."
I told him he was crazy but he said he'd be to us in an hour and I said I'd wait.
About two hours later Peter showed up with Alain and a work/study/intern at Bourgogne Marine, Samir. Alain shook his head over our story and said when we returned he'd have to remove the cylinder head, thinking the gasket may be damaged. He dropped off Peter and Samir and left.
We hooked up two lines to the boat, put Peter and Samir on the towpath, Cathy Jo at the helm and me on the boat pole to keep up off the bank and off we went.
Peter, Samir and I traded off as we covered the 5.5 kilometers, averaging about 3k per hour. We got to the last lock, put Peter and Samir ashore, motored into and out of the lock and found a place to moor in the upper basin at Bourgogne Marine. Alain would be around in the morning to begin troubleshooting.