Parts you should buy from the dealership ...

[jezza16v]

All the electrical sensors I've had from GSF I've replaced with Gen VW. Fan, Black and Blue (digifant) - The calibration has been out on all of them. The black one read very hot when in reality was normal but some other people have had big problems with under-reading ones. Blue one was just crap and messed up the idle. Fan ones didn't kick in as said above. AVOID AVOID AVOID

 Also has anyone else had problems with the thermostats? I think the Mk3 and the Mk2 ones are different spring strengths despite the same temp rating, I think that the GSF copy the Mk3 spring so don't open fully in a Mk2 giving the temp sat at the first bar instead of about half way or is this just the start of a fail? Add a badly calibrated black sensor and you don't know if your car is running a little cold or way too hot...

+100%  My experience as well, always ended up with dealer parts to get things right.

[X4MGS]

All the electrical sensors I've had from GSF I've replaced with Gen VW. Fan, Black and Blue (digifant) - The calibration has been out on all of them. The black one read very hot when in reality was normal but some other people have had big problems with under-reading ones. Blue one was just crap and messed up the idle. Fan ones didn't kick in as said above. AVOID AVOID AVOID

Interesting that as my 2 MK2's 8v Digis have the same issues... Both fitted with new GSF Blue & Black Senders & One reads too high and the other the temp needle hardly moves from cold...

Might just swap them over and see what happens...

[tony_ack]

All the electrical sensors I've had from GSF I've replaced with Gen VW. Fan, Black and Blue (digifant) - The calibration has been out on all of them. The black one read very hot when in reality was normal but some other people have had big problems with under-reading ones. Blue one was just crap and messed up the idle. Fan ones didn't kick in as said above. AVOID AVOID AVOID

 Also has anyone else had problems with the thermostats? I think the Mk3 and the Mk2 ones are different spring strengths despite the same temp rating, I think that the GSF copy the Mk3 spring so don't open fully in a Mk2 giving the temp sat at the first bar instead of about half way or is this just the start of a fail? Add a badly calibrated black sensor and you don't know if your car is running a little cold or way too hot...

My GSF oil cooler seems fine so far and I've not had problems with the smaller hoses I've replaced. O-rings seem to be fine from GSF too but perhaps I got lucky?
Door membrane was gen VW part when I got it from GSF but about £6 not £20 IIRC

Just to throw one into the mix on the thermostat/sensor debate - I have replaced the thermostat and black temperature sender with dealer parts, yet my gauge sits on the bar below half way (about 1/3). Oil temp is in the mid 80s - 90 degrees, so I suspect the genuine VW thermostat is faulty

[MRA]

bought the matrix feed/return pipes from GSF, and they lasted 3months before cracking. got the feed pipe from VW (£18.85 + VAT), and a genuine return one second hand for a fiver.