Today the car was traillered to Northampton Motorsport for mapping. As I hadn't managed to get the engine running, I was expecting a few teething problems and that's what we got.

Troy at Northampton Motorsport is a real expert, so he quickly identified that poor coolant temperature calibration was causing a lack of cold running enrichment. Moments later the engine was running smoothly and we set it at 2000 RPM to bed in the cam. From there on it all went a bit downhill.

Troy didn't think the engine sounded quite right, and neither did I. He guessed that the rockers were touching the rocker cover, and a quick inspection revealed that he was right. As it was clearly just the lightest of contacts, we decided to relieve the rocker cover. 15 minutes with the dremel and we were ready to try again.

On the next run we ran for a bit longer, until we could see we had a significant coolant leak from the front of the engine. Again Troy quickly identified that the radiator cap was the wrong one, being too short to push down properly on its seal. This was particularly annoying as I had only fitted a new cap as a precaution and because the old one looked grubby. The leak also seemed to be from the thermostat housing gasket (also new). A bit more investigation suggested that the bolts were bottoming, so we sawed few millimeters off them. Surely with a bit of sealant that would do?

The mis-matched coolant temperature sensor also needed addressing. The OMEX was maxing out at 60C, which was enough to get out of the enrichment zone, but we would get no warning of overheating. We decided to fit an OMEX sensor in the heater circuit as it wouldn't screw into the head. We were ready to go mapping. 

The next run proved otherwise. Once hot, the coolant came out again, this time apparently from the top hose union to the thermostat housing. The cooling system seemed to be pressurising to the point that it was finding the weakest link, wherever that happened to be.

We called it a day, packed up and went home.