thermostat

Posted: Wed Oct 08, 2003 8:20 pm

Hi guys

I have a concern about the temp gauge on my 1989 coupe quattro 10v kv engine,in that the temp takes a long time to warm up,usually sitting in the cold markers area on the gauge (sorry for being a bit vague but my gauge doesn`t have any numerical values just graduated marks) whilst driving around town but if I sit in traffic the temperature wil rise to about the centre of the gauge and the fan cuts and reduces the temp slightly but then as soon as I get moving again the temp goes right back into the cold settings again. Is this the stat opening too soon or getting jammed or could it be something else?
If it does require a new thermostat would you recommend replacing anything else ? eg water pump.
If it does need a new stat where should the gauge normally point?

Thanks Stu

UltraUser Joined: Jan 21, 2003 Posts: 4228

Once the engine has warmed up the temp should remain stable at around 90 degrees. As you drive and the engine cools the stat should close again.
Temp gauges on these series are best described as temperamental, but in your case I would suspect the stat. Depending on mileage the pump should really get changed at cambelt time. Evil or Very Mad

Posted: Thu Oct 09, 2003 12:41 am

This points to a thermostat problem - it sounds like it's stuck open which is the most common failure mode. You should not need to replace anything else other than the antifreeze which comes out when you remove the stat.