Club 80-90 Forums

the red light in my 2.1 dj has started to flash and stays flashing, the themp gauge has remained in the same position, no over heating, water tank full any suggestions as to how to fix please.

The first thing to check is the water level sensor and it's wires.
This is located at the top of the white header tank in the engine bay.
NOT the one behind the number plate flap, but the one to the left of that one.
Check the contact probes that go into the water are clean ( no oil or similar on them ).
Check the wires and connections are in good nick.

I have read that they don't work correctly if you only have clean water in your system ( it should be 50 / 50 water and G12 antifreeze ).

Next is to check the thing that looks like a relay, located on the fuse panel behind the glove box. It is the one numbered either 42 or 43 (they vary from model to model & are interchangeable). It is not a relay by the way, but a little circuit board that sends pulses to the probes and activates the red LED if the pulses don't find water across the probes.
This 42 or 43 thing are a bit prone to failing. A replacement can be got from a "wanted" on here or off eBay. VW still sell them but they are a bit pricey via that source !

Whilst behind the glove box, check the condition of the sockets for these "relays" etc and the condition of the "star" earthing multi connector fastened to the metal bodywork. (these often get a bit rusty and can cause such "issues")

let us know

just to add to Ghosts sound advice, the coolant level warning system is very intolerant to poor earths and poor connections generally. As well as the earth for the module 43 (terminates at the earth cluster next to the fuse box) is the earth for the level sender which terminates under the ignition coil. Other reported problem (but rare) is the centre nut of the temp gauge coming loose or not making a good contact with the membrane circuit.

ok had taken out the level sensor before and it looked ok.took it out again and cleaned it put it back in and the light went out.but it has since came back on.assume problem is this sensor coolant feels a bit oily to the touch it has been in for 3-4 yrs will have to change it it is the g12 proper coolant which i understood you did not have to replace

Yes it seems like you have "localised" the problem.

The sensor itself is just 2 probes, so other than dodgy wires, it cannot "fail".

When you say the water feels a bit oily, ok but does it look ok, as in, there is no signs of mucky brown oil in there ? ( I hope not for your sake )

After 3 to 4 years I think it would be a good idea to drain, flush & refill, if only to take that out of the equation.

Read up on the correct procedure for how to do this on a T25 in our wikki (link at the top of every page on here) if you don't already know it.

Re G12 - read up on that in the wikki too = 50 / 50 with the water.
Comma do a G12 type called Xstream G30 that is cheaper than the VW stuff (you need 2 x 5 Ltr cans to get the 9 Ltrs of antifreeze you should put in )

thanks ghost no the water looks ok pinkish it is a new vw engine only 15000 mls on it the old one had been over heated at a time so maybe residue from rad pipes etc i hope.thanks for the comma info.