2 "Water Temp" readings go seperate ways?

[frozen]

I have a Billion VFC (radiator fan speed control thing, where you can set what temp you want your fan to kick in) i have set to 85 degrees, which displays the current temp on the little display.

I also have a set of defi's, one of which is Water Temp.

Heres the strange thing...
Ever since installing my new intercooler, on idle my VFC shows the temperatures climb up pretty quickly (within 5 minutes i'd be over 105 degrees) where as the defi water temp shows the opposite... as in if the VFC goes up to 100 from 80, the defi guage is more like 60... as soon as i start driving again the temps quickly go back to 80 - 85 within seconds...

Its really odd... no idea what it could be.

I think i've also tried revving on idle and holding the revs up, off memory this also stabalised the temps (or at least quickly shot the defi guage up to match) but i cant remember the exact results of doing that...

Either way, somethings up any ideas on this one?

 

[Guest]

where are the sensors installed? both in the same place?

 

[Kristian]

^^^ That's what I was thinking - the sensors are in different spots.

 

[frozen]

i figured that.... but that doesnt help me is it bad if it never done it before? and revving the car (holding revs) or moving makes them even out? issues with the fluid not moving or something? i got nfi...

 

[SiliconAngel]

Define 'doesn't help me'? Do you mean they ARE in the same spot, or you're not convinced its applicable to your situation? Let me tell you, if you have one sensor before the rad and one after, you'll have MASSIVE differences in readings. You could even have one sensor in the path of cold air flow which will cool it down relative to the other... There could be all kinds of reasons. If you could show us some pics of where you have them set up, that would help to clarify.

 

[bradc]

If one is between the thermostat and the top of the radiator, and the other is between the bottom of the radiator and the entry to the engine then I would expect them to do exactly what they are doing.

 

[frozen]

its only been since i installed the intercooler... ill have a look today and see where the readings are from..