My 1994 LeBaron convertible exhibits a wildly fluctuating temperature. It will remain very low until the engine warms, and then it will shoot up near the top of the range, and while driving it will drop down to "normal" level foir a while and then creep back up, and then drop back down again.
I noticed that when it wnet all the way up I stopped and added water to the coolant tank, and it was empty when I started. After adding water, the temperature did not drop. I got it home and it is parked, but this fluctuation is unnerving. Any suggestions much appreciated!
a 6ya Mechanic can help you resolve that issue over the phone in a minute or two.
Best thing about this new service is that you are never placed on hold and get to talk to real repair professionals here in the US. click here to Talk to a Mechanic (only for users in the US for now) and get all the help you need. Goodluck!
- If you need clarification, ask it in the comment box above.
- Better answers use proper spelling and grammar.
- Provide details, support with references or personal experience.
Tell us some more! Your answer needs to include more details to help people.You can't post answers that contain an email address.Please enter a valid email address.The email address entered is already associated to an account.Login to postPlease use English characters only.
Tip: The max point reward for answering a question is 15.
Fiats have a reputation for electrical/electronic problems as they age and even when they are not very old they can manage strange things that even sometimes defeat the dealers, though the same can be said of many modern vehicles. I used to look after a Ducato motorhome and fortunately didn't need to get involved with much electrical work - the only faults were caused by the coachbuilders rushing around and being careless and not by Fiat.
I am not sure if the temp gauge is driven by the engine management or is a traditional circuit but either way the temperature gauge is in effect a voltmeter of sorts. Assuming the gauge is ok, the reading will only fluctuate if the voltage in the circuit fluctuates and that could mean the supply voltage is fluctuating or the resistance of the ground path is fluctuating.
With the traditional circuit the gauge is supplied by an electronically stabilised voltage and the ground path resistance is varied by the engine coolant temperature sensor and fluctuations could be anything from a faulty instrument voltage regulator, through faulty wiring or connections to the temperature actually fluctuating.
If the gauge is driven by the engine management the same approximately applies but checking the circuit becomes much more complex due to the need for circuit diagrams and specialised test equipment, though these would not be needed just to check the security of the gauge in the printed circuit of the instrument panel.
Check the coolant level. Sometimes when the coolant level is low, it will cause gauge fluctuations like you suggest, since air is getting into the cooling system. When air is in the system, it causes the thermostat to open and close frequently resulting is wild temp gauge swings.
P0420 and P0430 are catalytic converter codes indicating that the converter isn't working properly. Temp gauge fluctuating can be caused by a bad thermostat, bad temp sensor, bad wiring harness to the sensor. Also check for air in the cooling system. Read the post below for more information on the catalytic converter issues.
either the thermostat is getting ready to fail or the temp sensor isnt working properlythese engines also leak fluid from rear side of head after getting hot so check that so may have air in system because of the blown head gasket
Here's the thing. The ECU will shut down AC if the engine temperature is too hot. If the coolant temperature sensor is malfunctioning (lying to the ECU) telling it that the temperature is hotter than it actually is, the computer will turn the AC OFF.