MFA MALFUNCTION & POOR HEATER

[56 ragtop]

My newly acquired 91 GTI has a couple of faults. Firstly the oil temp on the MFA reads --- all the other functions seem to work, so I'm guessing that the sensor is at fault. Is this likely and where is it located? Also my heater is blowing hot then cold then luke warm. Ive taken the bypass valves off and the black plastic one is clear. However when you look down the metal one, the valve bit appears to be partially shut! Any ideas how these are supposed to operate. Is fitting a MK3 matrix and binning the valves altogether the answer?

[Gambit]

is it an 8v or a 16v?
on a 16v its on the back right of the head - little green wire

also, binning the bypass valves and going for a mk3 matrix is the ideal solution. either that or just replace the valves!

[carrie]

might sound silly but i assume you let the car run for a while as under about 50c the oil temp shows ---

[Veedubgt18v]

if its an 8v then the little green wire gambit is goin on about is plugged into a sensor ontop of the oil filter housing

[rubjonny]

Yup if the oil temp is below 50 degrees it shows --- and the wire on the sensor is black/green I believe, which is the one nearest the front on an 8v.  check its plugged in and the wire is in good nick, if not cut the spade connector off and crimp another one on

[56 ragtop]

Sorry guys, yes its an 8v. Its definately shagged, drove it back from scotlandand it never blinked. Gonna sort it this weekend. Cheers.

[rubjonny]

Oh and just to let you know I fitted a MK3 matrix and left my valves on (they are only a month old).  The heater works perfectly though! The only reason I left them on though is because the straight through piping I bought from the scrappy wasn't long enough