Just got a 16 valve Polo and having driven it for a bit now I notice the temp guage slumps to zero and occasionally moves a little so I suspect either a new thermostat or temp sender. Im hoping the temp sender as its a lot simpler to do. Im also hoping the fuel gauge is faulty too as I stuck a tenner in it last night and have covered almost 30mls and its almost in the red so 17.94mpg Question no smell of petrol anywhere though. Suspension is past its best and the leccy windows are slow to move. On the upside its pretty fast and seems to drive ok and has a decent interior. I was planning to spend a bit on it but think I will just drive it and maintain it. £650 is cheap I guess as I havent seen another for under a grand. any idea what the problem could be with the fuel consumption.

If the thermostat is stuck open then the car will run rich and use more fuel. (And won't get up to full temperature)   

It's a common vw problem. It wi'll be temp sender it should be a green plug occasionally blue or black and it located in the right side near the head near the thermostat.

Thanks for the tip Danny   Following a bit of a spruce up. Used my multipurpose cleaner and a soft brush to remove all of the mildew and dirt. Replaced the screws & caps in the number plates and a new tax holder. Cheap but freshens things up. Fuel light has only just come on so I am pleased its doing what its supposed to be doing . Cleaned up the throttle body and MAF using carb cleaner which cost me nothing to do and improves running etc. First proper long run out in it today and it really is a little gem. That little 16v unit is so willing & eager and plenty fast enough for normal road use. Any thoughts I had of selling it on have faded away. I think its a keeper.

Cool nice one mate. That engine is under powered in a golf but wicked in a polo or lupo

I decided to fit the temp sender last night. I am still waiting for the new thermostat and I was going to do that first to see if it resolved the problem but I thought bugger it. It looked simple enough release the pressure in the header tank pull out the clip on the sensor and remove the old sensor. I had placed a bowl underneath but I still was not expecting so much water to pour out. Could I get the clip back in for the new sensor ? could I buggery. I then commenced stripping down various bits that were in the way just so I could see what I was doing. Success its in I top up the coolant and run the engine and no leaks   Next step fit the new thermostat and hopefully that will be it. wont be here till tomorrow though.

So how was the temperature gauge while running the engine?

Still to high but hopefully the new stat will cure it who knows   

How high?

Well its above the center mark and I'm guessing its at about 110+ and as far as I can tell it should be more like 85 ish

It should be 90 mate. Might have a hotter stat in it

Cheers for that I will know more when the new stat is fitted   will report back   

So to continue new thermostat has arrived with new cover. Rolled up my sleeves and got stuck in and I was scratching my head when I noted there was no thermostat to replace so I fitted the new one. On the test drive I noted the guage was beginning to register so thought ok that was the problem but I noticed the temp rising towards 110 and still climbing slowly ???

Schoolboy error took it all apart and I could see the stat had broken through the bridge inside the thermostat cover. Stupidly I had used the old cover so I fitted the new cover took it for a long drive and eureka its perfect. Can only assume the previous owner had the same problem and either could not see what the problem was or saw the problem and had no new stat cover so just removed the stat and left it like that.

Unfortunately the uneven idling problem came back so I stripped out the throttle body cleaned it thoroughly with a toothbrush and carb cleaner and as far down into the inlet manifold as I could. I then unhooked the battery for a few hours as I read it clears the ecu memory and resets the throttle body. Bugger me all that worked and touch wood its been perfect ever since.   

Congrats mate sounds like a busy day. Well done.

Yes it was but well worth it, what a difference it is now. Thanks for all the help   

Well done   That's what forums like this are for   

No problem pal any time