My 2001 135 Optimax had starting problems the other day, like it was very cold. Once it started it ran very rough for a couple of minutes, but then seemed to be OK. Later that day the heat alarm went off. Not knowing the exact maintenance history of the motor I replaced the water pump, but the heat alarm is still going off. The alarm does not trigger at idle, but at about 1000 RPMs, if I bring it back to idle the alarm shuts down. The shop manual indicates that a hard start, rough idle, and the heat alarm may be the result of a bad Poppet valve. Does the make since, or should I look for a different cause of the heat alarm.
