I have a 2004 1.8T and my temp gauge(water temp) has been dropping from 1/2 way(normal) all the way down to C then shoots back up to half way. Doesn't seem to matter if heat is on or off. I had the timing belt and water pump done already and the vehicle has 92,000 miles on it. Also, the coolant level is normal.

Any ideas?
Thanks-
Ryan

 

I would first look to the coolant temp sensor in the flange (replace the flange too, at your miles its probably about to go anyway). Then look at the thermostat.

 

Thanks for the info. Are these major/costly repairs or minor/inexpensive repairs. Not sure how labor intensive these jobs are or the price of the parts. Thanks!

Ryan

 

Parts arent that bad and you can DIY them.