8v 1990 Mk2 Golf GTi - Fan and coolant advice

[catbaiter]

I'm new to the forum, and new to owning a mk2 golf gti (though I've had a few Sciroccos in the past), so I hope I'm not going to ask a load of stupid questions, but if I do, go easy on me!

I've just picked up a 1990 mk2 gti, and for the most part is great. But I've noticed that the radiator fan seems to be a bit enthusiastic, coming on fairly early and running for a while after the engine is stopped, once or twice it's run for over 20mins. When it does that I've disconnected the thermo rad switch and let it sit for an hour or two, then reconnected the switch and it's stayed off.

Also the coolant gauge never gets above the first white block. The MFA shows the oil temp at about 90-96, occasionally going up to about 100-108 on the motorway at 80mph. Fuel consumption seems a bit high too, though I'm temped to say that's just me being a tightwad and my other car being an efficient boring diesel. The engine idles a tiny bit lumpy too, but not so much that I'm really worried. It's a pretty old car and it's done 180k mls!

Mostly I'm trying to work out how to get the fan and coolant gauge working properly, as I'm told that might be connected to the mpg issue. I'm going to spend the weekend flushing and then changing the oil and oil filter (probably not related, but needs doing), flushing out the coolant and replacing the thermostat and rad switch (both from GSF) before putting 50/50 coolant back in. But before I do that, is there anything else I ought to check first?

Cheers

[dragonfly]

Replace the blue and black sensors on the water flange pipe (including new O rings).

Edit- this might also help: http://www.golfgtiforum.co.uk/index.php?topic=257632.0

[catbaiter]

Hmm. I just popped off the switch for the blue sender, and the engine changed a little (it seems to run better  ). But while I was there I noticed that one of the vacuum hoses running from the front of the throttle body to the round black plastic solenoid/switch (next to the air box) has been cut by the uncovered cam belt (I'm ordering a new cover right now!). I'll replace this too (may as well do all of them). What difference might that make?

[dragonfly]

The 8v isn't as bad as the 16v when it comes to vacuum leaks.  But it can stop it running and idling smoothly.

[catbaiter]

I've just looked at the rest of the vacuum hoses, and they're ALL perished or broken.  Good thing I ordered 3m of new stuff!

I'll do the vac-hoses, the blue and black sensors, the coolant, the stat and oil/oil-filter this weekend. No doubt it'll be something totally different which costs 50p to replace.