Originally Posted by
matthart
The gauge sensor is only a 1 wire thing, it relies on a good earth to compare for the signal. Check it earths well into the head, and that the engine is earthed well to the body.
What management? Plug your laptop in and see what the ECU thinks the water temperature is.
Just seems strange that it will fluctuate to begin with then after 15-20 minutes it's fine.
Its on Omex 600 and I dont have a laptop or software sadly.