I have read loads of posts regarding 156 thermostats and running temperatures but I never really seem to find a conclusive answer for what's going on with mine, so I thought I'd just ask in my own thread
So here goes.
When I'm driving, the gauge will be anywhere between the 70 and 90oC markers. It'll gradually move itself up to 90oC, then zip back down to 75ish (quickly, in about 5 seconds), then creep back up to 90 again, then straight down to 75. At constant motorway speeds it sits at about 85 but does bounce about a bit. Stood still in heat it'll move a smidgen above 90 then shoot back down to 75 again. Any ideas?!
Just as another point, the heater does get easily as hot as I would expect, and the other day on a nice long motorway trip I achieved a very respectable 34mpg...normally it's around 30 though.
So what are your thoughts? Should I replace the thermostat, or is this more likely to be fun italian electronics/a bad gauge? Any help would be much appreciated.
Oh, and if it does need changing, can I do it myself?!