The new (to me) E350 runs at 80 degrees on the coolant temperature gauge, not 100 like the E55Ks. It seems to take longer to come up to temp than the E55Ks, too, but I had assumed that it was just that it read differently. Not so... Sunday morning, trundling along at 50(ish) mph in the long stretch of roadworks on the M3 just before the M25, the coolant temperature was dropping...dropping...dropping, and when it reached 60 degrees or so, the EML came on. When I stopped to look under the bonnet, leaving the engine running, it came back up to 80 quite quickly. Once on the M25 and up to normal cruising speed, back to 80 degrees. The new 'stat should arrive tomorrow, and it's going to be a doddle to fit; compared to the AMGs, there's just so much space under the bonnet in front of the engine. Woo Hoo! I'll try the cheapo-cheapo Chinese OBDII reader I received two Christmases ago as a desperation present to see if I can read and clear the fault code, but if the mini disc instructions it came with is any indication, it may not be much use; the codes decode library does not recognise a single code. Wish me luck.