I hate to bump this thread, but I just wanted to give an extra thanks to the OP. I just purchased my 335i with 50K miles on it and the thermostat was bad. So I decided to change the plugs, give it an oil change, delete the CDV and fix the thermostat. Everything else was a piece of cake but this thermostat has been a real PITA, the hoses are hard to get to and a pain to pull off.
After removing the Thermostat I noticed that the plug wires were nearly sheared through and that it possibly wasn't a bad thermostat but just the wires grounding into themselves. So I cut the plug off to re-pin and that went well, other than I forgot which side the colors went to. Luckily this thread had a picture of the plug and wires so I'm out to go solder upside down in sticky coolant. It's funny because I purchased the car so I wouldn't have to work on my project car anymore.