Ian Byrne

Hi all
i drive a 97 Audi b5 1.6 the problem is sometimes when driving the temperature gage drops down.
only happens sometimes especially cold weather. Any idea

Panzer A4

Possible causes:
Thermostat malfunctioning/stuck open
Air in cooling system
Bad coolant temperature sensor

Bob86ZZ4

My '98 does that sometimes too. The dash gauge will sweep down to 0 and stay there for a bit and then ease back up to the middle where it belongs. I've hooked up my scan tool and watched the engine coolant temp and that sits right at normal when the gauge is down at 0. So, at least on my car, it's something to do with the coolant temp sensor for the dash gauge or it's the gauge itself. I think the gauge gets it's signal from a different sensor than the computer does? I haven't dug further into my issue since I'm quite sure it's not effecting anything but the gauge. Have you hooked up a scan tool to compare your results to mine?