Question around running temps

[matts4]

This may sound like a daft question, but just wondered how my car (Audi B6 S4) mantains such an accurate water temperature?

Whilst I can understand that it may be set up for the hottest conditions to run at 90 degrees (on the gauge when sat in traffic in external temps during the summertime of 30 degrees C), why is it that when I was driving it a week or 2 ago, and with external temps of -14c, how does it mantain 90 degrees on the gauge still?

Is that a sensible question to ask?!

And no, the gauge isn't stuck.

Someone enlighten me please

Thanks
Matt

[stevieturbo]

matts4 said:

This may sound like a daft question, but just wondered how my car (Audi B6 S4) mantains such an accurate water temperature?

Whilst I can understand that it may be set up for the hottest conditions to run at 90 degrees (on the gauge when sat in traffic in external temps during the summertime of 30 degrees C), why is it that when I was driving it a week or 2 ago, and with external temps of -14c, how does it mantain 90 degrees on the gauge still?

Is that a sensible question to ask?!

And no, the gauge isn't stuck.

Someone enlighten me please

Thanks
Matt

2 things

In car gauges arent every accurate.

and a thermostat, same as every car.

Although it may likely have better air ducting/control through the radiator too which would help in cold weather

[matts4]

Makes perfect sense, I just didnlt realise how much the thermostat was working I guess.

I just expected to see the temps creep up and then go down a bit once the thermostat opened up. But I guess if the gauges ain't that accurate + if the stat only partially opens, then that would explain it.

[Milky Bar Kid]

The stat will only be fully open at, in your case, 90C. It will either be partly open at lower temps, or have a slight bypass to allow water flow at lower temps so that it is constantly altering to keep the temp right.

[Yuxi]

Most temp gauges now dont show the reading from the temp sensor but are ECU controled, if the temperature is somewhere near normal it will sit in one place, you wont see any change unless the engine is grossly over or under cooling.

[anonymous-user]

From about 1995, engines have had "bottom hose" thermostats, these give a much much better control of engine warm up, and significantly reduce the "Thermal shock" that occurs with the old school "top hose" thermostats. As a result, most engines will now run with a 2 to 3 degree window when the car is moving, and only creep up by 5 to 8 degC when stationary before the cooling fan starts to work (which are also now speed controlled so can come on sooner and more smoothly)
The temperature gauge generally will not show less than a 10deg swing, assuming that it is actually a "real gauge" (most cars now have a "fake" gauge that is ecu driven to point at the middle of the dial between approx 70 and 95 degC...........(manufacturers used to get a lot of "my car is overheating claims when in fact it was normal but the gauge wasn't point EXACTLY straight up ;-)