with my DIYgaugcluster with the Maxigauge (see thread) I installed a second watertemp sensor. The sensor sits also inside the coolant reroute adpater - just like the OEM sensor - just about 3cm (a bit over an inch for you Americans...) away.
The OEM sensor gives me values of ~85-95°C (185° F- 203°F) in Tunerstudio. Just normal driving, some short boosted runs.
The VDO sensor gives me values of 95°C - 115°C ( 203-239 °F) in the Maxigauge-display.
I tested, if a separate ground to the sensor helps - but there is no change.
About the sensor:
I got the sensor from this webshop -
They even have a site, where all the values for the sensors are shown:
The values are similar with the 92-027-004 charateristic curve, which is the curve that Hakan programmed into the Maxigauge.
The sensor is a little hidden behind the engine, but I can see the max. 120°C stamp on it - so I think it's the correct one.
(BTW The sensor reads perfectly match with the oiltemp, OEM watertemp, Manifold air temp at 20°C when I start the car.)
My OEM Mazda sensor sits in exactly the same spot of the engine in the same aluminium adapter only about 3cm away.
I am about 90% sure that the OEM sensor reads correct, because the values for my engine are reasonable 85-90° at cruise and up to 95°C at higher speeds.
The VDO sensor reads up to 115°C... which I don't see happening with my cooling system... (coolant reroute, 86°C thermostat, huge cooler)
So what do we have:
- Maxigauge programmed correctly - check
- Sensor correct - from what I can see with it in the car - check
- wiring directly from the sensor to the Maxigauge - check
- sensor has good common ground - check
I can't wrap my head around that...
Please help me out - what could possibly be wrong?