Slow warm up/ temperature fluctuating?

[austengti]

Since buying my Gti two weeks ago i've noticed how long it takes to warm up, but now i've noticed something new......

Drove about 15 miles (20 odd minutes) on an 'A' road and the car was still only half way to 90, but if you get a bit throttle happy the temperature will rise to the 90, but when back cruising along it will then drop again to about half way. Also if your just town driving it will rise to the 90 and stay (so far anyway)

It was cold out, about 1 degrees, but still I wouldn't of thought this was normal. I had a quick search of the forum and it ranged from thermostat(what I assumed) to leaky radiators and fans not working 

Anyone happen to know the more likely cause? Not up for paying a garage to fix a fault which is hopefully not serious and an easy/cheap fix!

Cheers

[Stevepd]

Probobaly thermostat, but perhaps the bypass thermostat. Do a search and all will be revealed

[Human Joist]

Right. Read this for the slow warm up. The temp dropping will be your main stat so change that too.

http://www.mk5golfgti.co.uk/forum/index.php/topic,78341.0.html

[GrayMK5GTI]

Sounds similar to my problem: http://www.mk5golfgti.co.uk/forum/index.php/topic,80793.0.html

[austengti]

Cheers lads!Brilliant write up/Guide Shame changing the main stat doesn't look so easy