Porsche Enthusiasts Club Forum

Hi,

I get a permanent coolant level warning, so I guess I need to get the sensor out and have a look, can this be removed with the expansion tank in place, or does it need to come out too ?

Thanks

Hi George,

It may not be a sensor problem, but a short to earth somewhere along the wiring between sensor and the control box.

I've never removed a sensor but on Rennlist the experts claim it can be done without removing the tank (which would be a pain as have to disconnect three hoses).

Bear in mind their experience is largely with LHD cars with coolant tank on RHS:


"you dont have to remove the entire tank, try removing the one bolt, loosen the other so you can rotate the tank, remove the nut and pull the sensor out. Its quite simple."

"you need to loosen one of the screws then pull the other completely out. Pull the easier screw to reinstall. But you can then rotate the bottle to then unscrew the large nylon nut with some channel locks and you can remove the sensor."



Like many 928 jobs it's probably easier to describe than to perform! Worth a try though assuming our cars are 'mirror' image.

If you do decide to remove tank (it is a good time to replace tank, sensor and cap) then it's easier to disconnect the hoses at the ends remote from the tank, then remove them from tank with easy access once out. To install put hoses on tank first before bolting it in.

Let us know - I've never worked on this so keen to hear any tips.

Ok here's an update, and thanks for the tips Adrian. I had to remove both the bolts that hold the tank on, fortunately the nuts seem to be captive otherwise they would be tricky to get back on, having removed the bolts, the tank can be encouraged out from under the wing with a bit of heaving (at first i thought there was a third bolt, but it's just held firmly by a metal bracket), there is no need to remove any hoses, you do need to remove the air box lid though. Once the sensor top is clear of the wing it can be removed quite easily.

Now to the problem, having removed the sensor, it seems that the float on the bottom has degraded, and no longer floats... the switch itself is function electrically, so I'm wondering if it would be possible to fabricate a new float. I am wondering if a synthetic wine bottle cork would work, but not sure if it can handle the temperature. Anyone got any ideas? The original material is unrecognisable.

Applaud the ambition to repair it Geo, but a new sensor is only £37 so I would spring for one!

Alternatively 928 International sell used, working ones for $25. But they have a 1/2 price sale on used parts so would be about £8 at current exchange rate. If you picked up some other bargains at same time would be well worth buying from them if you can wait couple of weeks for shipping, or could be worth extra cost of courier in which case I get stuff from them within 2-3 days of order.

Thanks for write-up - very useful to know it's possible to get it out from tank of RHD car. Just looked at PET which shows tanks is screwed into couple of speed nuts rather than captive nuts, which explains why you could get the screws out without losing your nuts!

Save you a bit of time as well to fit another rather than fashion your own?
There is at least one S4 being broken at the moment on Ebay as well.