Dodgy Thermostat or something else

[Jag]

Hi All

My knowledge on the Polo isn’t brilliant, the wifes 1999, Polo 1.4 Auto was experiencing issues with the temp gauge constantly dropping when driving along and only rising when idling. I thought temp sensor which I changed but didn’t resolve anything. Next I thought thermostat, so I pulled out the thermostat and noticed the housing for the stat was broken (the bit where the pin pushes against) common problem I believe. Anyway I replaced the housing and stat together. Whats happening now is that the car does take a time to heat up and gets to 90 degrees after a while of driving.. but noticing top coolant pipe is hot but the bottom is stone cold. However temp gauge isn't going down when driving. So I’m guessing the stat isn’t opening up.. How do I test if the stat is working as it should outside the car.. Do I just put it in bowl of boiling water to see if it would open up before I go out and get another one. At times on a long town drive the temp does creep up slightly but goes down back to 90… Help much appreciated.. Also noticed the fan hasn’t come on yet possibly due to the cold pipe going into the rad.

Help much appreciated..

Jag

[alexperkins]

Its likely the stat isnt working (even though its new)

Replace it with a genuine VW part (copy parts are absolute rubbish quality by comparison) and the problem should clear.