next problem - wild temperature gauge

[violet]

This car is driving me crazy  )  Last night on the way home waiting in traffic my heating gauge shot into the red.  when i started moving it came back down, all ok.  Checked engine when i got home which was only a few miles from when the guage went crazy.  Turned the engine back on left it running for a few mins and it was perfect.

Got in it this morning and literally within a minute it swung straight into the red. carried on and it was swinging all over the place.  then went right off the scale, turned around and headed home, switched the fans on and it suddenly droppped down.

have read a few threads about thermosats being stuck open.  Anyone had any similar problems?

Major issue i have is that i was due to drive to bham tomorrow to get the dash fixed, think it would be wise not to do that and not drive it until next week when its off to the garage.  However really needed it this weekend, thank goodnes i have not sold my little smart for four.

Its booked in the garage for tuesday and just hoping its a bad thermosat, but is there anywhere is can look to see if i have a split hose, expansion tank or whatever else i can look at.  Do i trust the dial, if its not going up into the red or best to avoid driving completely.  Have read turning off the car sometimes resets the thermostat, need to go about 30 miles on sat and really need a big car for the event i am going to.

I love this car to death, but i might fall out of love with it quickly, dont mind spending money on it, knew i would have to, but everytime i get in it something else goes wrong

[Greydog]

Sad to read your problems but like you say there is a good car hiding in there.
Are there are no codes ?? showing or readable
If you turn on the ignition without starting and the temp needle moves across I would suspect the sender not the thermostat. If it only occurs with the engine running I would play safe and suspect the thermostat.
Fingers crossed its a sender

[violet]

Thought I would take it out.  Didn't get a few 100 yards before it went straight into the red.  Checked the coolant level seems fine.  Engine  not hot.  But the pipes coming out the expansion tank where very hot. 

Half my dash read out is missing so hard to see any faults.  Was due to get that fixed tomorrow.  So car going nowhere  just hope I can get to the garage Tuesday.  Don't want the expense of getting it towed.

[davesavage257]

There are lots of things it could be, viscous fan, waterpump, airlock in one of the coolant lines, thermostat.....
Can't remember for sure, but think the waterpump runs off one of the accessory belts, could check the belt is ok, not sure whether these have the impeller problems some BMs did. 
Good luck

Dave
2003 BMW X5 4.6iS Auto

[Ubatoid]

This can be a sign that the thermostat electrical heater has failed and coolant has leached up the wiring loom into the E box. A quick code read will give you a clue, look for "Activation map cooling" fault. But I would look at the plugs to the engine ECU first off, this issue can be the death of the engine control.

[AVI-8]

You said that within a minute the temp shot up into the red, so presuming the engine was cold to start with you can definitely discount the thermostat, viscous fan and water pump, my bet would be on a faulty sender unit or a problem with the wiring to the sender unit. Or maybe the gauge itself It takes a good 3-4 miles of driving normally for the engine to reach normal operating temperature which would then cause the thermostat to open.

You mentioned that you turned it off then on again and it was normal which would also point to an electrical/sender unit problem

[violet]

Turns out it was a dodgy instrument cluster.  Knew it needed the pixels sorting.  It turns out to be a 4.8 cluster in a diesel cluster housing.  It was a bad self repair.  Lights disabled etc.

Anyway car fully checked and fine.  Currently driving around with a loaned 4.4 dash and everything is fine. Loving the mpg guage on this dash been trying to keep it above 20 mpg which is a difficult feat.

New, well second dash being fitted next week so back to the 4.8 dash.

It was a bit worrying it didn't help when the RAC man took a sharp intake of breath and said sounds like a head gasket as he loaded it on the back of his lorry.  At least I have a good garage that is helping to resolve it in an economical way.

[Greydog]

Your instinct was right Violet the good car is starting to surface. Hopefully the bad bits are behind you and you can start to enjoy your V8. Forget trying to get 20mpg it wont happen, just when you have been pootling around like a member of the cast of Driving Miss Daisy (20 mpg) you will need to open the tap to pass something or join the Motorway, the grin will come back and Miss Daisy disappears in a cloud of dust 17 mpg is normal.
Remember we are helping the Green Revolution without V8 drivers the Greens would be out of a job.

[X5Sport]

An AA man told my Dad his head gasket was blown a few years back.  It was a broken radiator hose clamp!  With the best will in the world their mechanics are fine with your average ten year old Ford Fiesta but anything as compkex as a modern BMW just has them guessing.

Glad it's getting sorted finally, so you'll very soon be seeing and driving the car as it should be.

Richard