View Full Version : Coolant temp sensor. Does it either work or NOT?

05-13-2007, 05:07 PM

Just a quick questions.. A coolant temp. Sensor, does it either work or not? I mean could i give false readings.? On my PFC commander it show 76-79 degrees celcius almost no matter what i do.. If i beat it up at a track/drift it reads around 88 degrees celcius. It does read from around ambient temp when started up and the temp rises as the engine is getting hotter. But i just think its weird that it doesnt go above that.. And actually i find that the engine runs smoother with the PFC as soon as the temp gets above 80 degrees celcius when at a track.?

So is the temp sensor shot or does the water temp just run somewhat low?

05-13-2007, 05:20 PM
personally, if it read ambient temp when it first started up and shows operating temperature, I think it is working properly.
what is your cooling system setup? most engine runs between 74-84 degree celceius in normal driving operating condition, with around 80F ambient temp.

Sitting in traffic, with A/C full blast or beat the chit out of it it might reach around 90C + depends how well is your cooling system.

that's from what I have seen with my techtom

05-13-2007, 05:56 PM
Well... Thanks for the answer.. It seems quite normal then. My cooling setup is stock. That means stock radiator, viscous fan and cooling shroud.

I just thought that it could be a reason for my cold start issues, but then its rather mapping in the PFC. Just seems weird a have to do LOTS of tweaking of the normal and coldstart maps. Doesnt seem like alot of people have to do that.

05-13-2007, 08:52 PM
well, good to know
the stock clutch fan with fan shroud can pull a pretty good decent amount of air, but at least you are not over cool.

05-14-2007, 10:45 AM
My car with a PFC sees very similar temps and very often runs right under 80C. I would say that your car is operating normally. The main reason your car smoothes out over 80C is that 80C is the last cold start correction point in the warm up map. There is a correction of 0 over 80C. Anything under that and you are adding a few extra ms to your injector pulse and running rich even though the car is basically warmed up. I think the PFC adds an excessive amount of warmup enrichment in this area. I went into mine and redueced the 50C point (it interpolates between the 50C and 80C point) to almost 0 so that there is very little correction when the car is almost at 80C at normal operating temps.

05-15-2007, 09:18 AM
trust me, stock temp sensor works, and is accurate if hooked up via consult/ecu. the stock temp GAUGE sucks monkey balls. but the sensor works just fine. it's been anywhere from 40F to 240F on me.