Temperature sender?

[jennettsjohn]

Hello there,

I did post a rather long-winded thread a couple of weeks ago, but got no replies. This is a more concise version of my problems (possibly):

Car - 2004 Touran, 1.9TDi 77kW (whatever HP that is)

1) After driving through heavy rainstorm glow plug warning light flashes and the engine stalls. EMS light is on and stays on. EPS light comes on, but goes out and stays out the next day. Had scan done which highlighted problem with glow plugs. Cleared fault and changed glow plugs.

2) Around 6 weeks later, after heavy rain, the same thing exactly with glow plug light flashing and car stalling. After 1/2 hour car started and drove fine for 4 weeks.

3) I then noticed that the temperature gauge was dropping when under acceleration, regardfless of the gear, and recovered to normal position (90 deg) when gas pedal steady. This continued for around a week when the gauge stopped working altogether and the cooling fans (which have never started in the 2 years that we've had the car) started running as soon as the ignition is switched onand keep running until the ignition is turned off.

4) The engine idle revs are quite high (over 1000rpm) since the gauge stopped working and the fans started running, especially when the engine's cold, but do drop to around 800 - 850 eventually. When changing gear, the revs increase before dropping when taking the foot off the gas pedal.

4) The audible warnings stopped working (seat belt, ice warning, headlights, low fuel etc) about the same time as th original problem in the wet. Also I've recently noticed that when adjusting the driver's door mirror, the passenger side mirror also moves, but not vice versa.

I'm hoping that the problem with the fans and the temperature gauge is caused by a faulty coolant temperature sender unit. Where would I find this and can I remove it without losing coolant?

Would this faulty unit indirectly cause the problem with engine revs?

Would water ingress somewhere (possibly a faulty temperature sender) cause the stalling problem and cause some kind of short which causes problems in the ECU making other stuff not work?

This has turned out to be a lot longer than I originally planned, but there's a lot of stuff going on which is puzzling. I'm loath to take the car to local dealer after they told me after a service inspection that both rear springs were broken and when I looked later they obviously weren't.

Has anyone else had any of these problems?

[Crasher]

I think you need another code read and this will probably show a faulty coolant temperature sender but there is also the possibility that the fan controller is faulty and this means changing both fans and the frame to deal with this in the approved way. The sensor is located in the water housing on the end of the head over the gearbox and is easy to change WHEN THE ENGINE IS COLD but you will loose about a litre of coolant so buy a bottle of G12++ when you buy the sensor. I also suspect you have a faulty crankshaft speed sensor and this may not show up on a code read, for some reason they often don’t.

[jennettsjohn]

Thanks for that Crasher.

Is there a separate temperature sensor for the fan activation and for the gauge, or is it all done by the same unit? Is the crankshaft speed sensor an awkward job to replace, or is it fairly accessible?

You don't have any ideas on the stalling in wet conditions?

Thanks anyway, I'll get a code read done and see what comes up.

Cheers,

Jennettsjohn.

[Crasher]

The sensor is an all in on unit.

The crank sensor should be easy IF the bolt comes out, if not it is a complete nightmare gearbox out and clutch off using a special VAG alignment jig to fit a new sensor ring, totally daft!

The wet weather stalling may be down to the crank speed sensor getting wet.

[jennettsjohn]

Iknow it's been a long time since I started this thread, but after the summer hols and getting back to work, I've had no time to update. Anyway, just to let you know that the problem was a worn wiring loom in the end - hence the water-related faults. I'd had the front end repaired after an accident and the repairer left the wiring loose so that it was wearing on the cooling fan. A bit of tape and some care and attention got it fixed. Got to thankthe local guy in the workshop at the end of the road for not taking the easy option of replacing stuff before he thoroughly checked everything out.