Temp gauge problem

Cucullan

I bought an 01 Mondeo 3 months ago and have had it back 3 times to the garage where I got it (Hyundia dealer) because the temperature gauge is not reading properly. The mechanic told me he changed the sensor and the thermostat and that the engine temperature is ok. After I got it back last time I took it to a differant mechanic and got him to check it out and he told me there is no thermostat in the car that it has been removed and the engine is running too cold. What might be the reason for them to take out the thermostat? By the way I took the car straight back and told the garage this as its still under warrenty so it should be interesting to see what they come up with this time.
Anyone any ideas?

AMurphy

Why remove the Thermostat.
several possibilities; The old one was stuck closed and the car was overheating, didn't have a new one on hand. quick fix.

Even with the std and functioning thermostat, it still overheats, so to fix that remove the thermostat completely. Quick fix.

Radiator is plugged up a bit, so to prevent overheating, keep it overcooled.

it's badly tuned, tends to overheat. overcool it, rather than fix the tuning.

Anyway, what was wrong with the temperature and/or gauge in teh first place?.

Cucullan

What was wrong with the temp gauge in the first place was it never moved to normal position when the car was moving. If i stopped the car and left it idle for a while it would move some of the way up. Its been like this since I bought the car and like I said its been back to the garage 3 times to be fixed but they don't semm to be able to fix it or else its going to cost them too much to fix it as its under warrenty. Either way I told them I don't want the car back this time till it is fixed and the temp gauge works as it should.

AMurphy

Well if it is missing a Thermostat, it sertainly won't heat up while moving, the draught simply passing through the rad as you move will keep it cool.

Howver, when stopped, maybe after a hot run, it should heat up, as there is no airflow until the temp gets high enough to activate the fans.

Also, some cars have gauges that may be off a bit, even when everything is running normally and well. Just a gauge calibration item.

Nonetheless, put the correct Thermostat in it and have the Rad Cap checked or replaced also, again with the correct one. You have already replaced the sensor, you indicated. Make sure they replaced the correct sensor. Some cars may have 3 or 4 of the darned things. 1 for the EFI, 1 for the A/C, 1 for the fans and 1 for the gauge. Lunacy I know, but I have certainly come across 3 in the Camry.

Then see where the needle lands.
Assuming it still does not operate correctly, I'm not sure there is much you can do about a faulty gauge other than replace the whole instrument panel.
The thermostat is more important than the gauge being correct.

mondeoman

yeah are you sure they replaced the correct sensor,on my mondeo there are 2 sensors fitted to the thermostat housing,1 for temp gauge & 1 for radiator fan.mines a 1998 but it should be similar.
have a look at 'fordmondeo.org' you should find an answer there,i always have in the past;) .
there no way they should have let you have the car with no thermostat

Cucullan

mondeoman wrote:

yeah are you sure they replaced the correct sensor,on my mondeo there are 2 sensors fitted to the thermostat housing,1 for temp gauge & 1 for radiator fan.mines a 1998 but it should be similar.
have a look at 'fordmondeo.org' you should find an answer there,i always have in the past;) .
there no way they should have let you have the car with no thermostat

I don't know whether they changed 2 sensors sure they told me they changed the thermostat and there wasn't even one in it at all when I got my own lad to check it so they're already lying to me about that. They've had the car since Thursday and I've heard nothing from them since so I'll have to wait and see what they come back with this time

BrianD3

I have found that some people refer to the fan switch/sensor as the "thermostat". So perhaps that's what they replaced. They don't sound too competent in any case.

As the others have siad, there can be a number of sensors that measure temperature. There may even by separate sensors for the temperature gauge and the idiot light.

The main worry I would have about the car is - why was the thermostat removed in the first place. This is often a sign that the car was overheating and someone wasn't arsed to investigate it properly.