Suzuki DF 140 Temp Alarm

[whitty]

I need some help. The other day my temp alarm started going off when cranked. If i cut the engine off and crank it back up it may or may not go off. If it didn't go off once at speed it wouldn't ever go off again until maybe the next time it was cranked.It was peeing water good and the engine was not hot when touched. I have replaced the water pump and impeller. I think it is a sensor but how can I find out which one it may be without buying a $300 sensor that I may not need. Also someone told me I could take the sensor out and clean it. Would that work?Any help on trouble shooting would be appreciated.

[Harper]

You have temp sensors in two locations (not counting intake air temp sensor, which we are not discussing). There is one for the exhaust temp, and one for the water jacket temp. My DF150 also has a cylinder head sensor, but I dont see one listed for your DF140. In any case, the two sensors are exactly the same, have the same part number and are interchangeable. The sensor costs less than $50, so buying one won't break the bank. From the way you describe the alarm, it only goes off at startup, which to me definitely sounds like a sensor glitch. So my advice would be to buy just one, replace either of the two sensors, and see if that solves your problem. If you replace one and still have the problem, remove your new sensor and use it to replace the other. The overheat alarm is triggered by the ECU, which bases its determination on not just an actual overheating condition, but also on a faster than expected rise in temperature. So if the ECU sees the temperature rising much more rapidly than the programmed expectation, it will sound the alarm well before there is an actual overheating.

[whitty]

You have temp sensors in two locations (not counting intake air temp sensor, which we are not discussing). There is one for the exhaust temp, and one for the water jacket temp. My DF150 also has a cylinder head sensor, but I dont see one listed for your DF140. In any case, the two sensors are exactly the same, have the same part number and are interchangeable. The sensor costs less than $50, so buying one won't break the bank. From the way you describe the alarm, it only goes off at startup, which to me definitely sounds like a sensor glitch. So my advice would be to buy just one, replace either of the two sensors, and see if that solves your problem. If you replace one and still have the problem, remove your new sensor and use it to replace the other. The overheat alarm is triggered by the ECU, which bases its determination on not just an actual overheating condition, but also on a faster than expected rise in temperature. So if the ECU sees the temperature rising much more rapidly than the programmed expectation, it will sound the alarm well before there is an actual overheating.

Thanks for the info.