the gauge goes back to cold when ignition off
2007-03-04 21:47:32 · 11 answers · asked by meldeg39 1 in Cars & Transportation ➔ Maintenance & Repairs
There are three reasons why this could happen:-
1) The sender unit is faulty and will need to be replaced.
2) There is an earth fault on the wiring.
3) The engine is overheating.
Given that the engine has not blown up and there is no huge amount of steam coming out from the bonnet, it is safe to say the engine is not overheating.
If the sender unit is faulty it is very easy to buy and new one and replace it.
The worst possibility is that there is an earth fault on the wiring, is so you will need to remove the dash to get access to see there wiring loom and look for obvious damage. Check the push fit electric connections and hope it is obvious where the problem lies.
Good Luck
2007-03-04 21:58:45 · answer #1 · answered by Anonymous · 0⤊ 0⤋
There is another obscure possiblity - the gauge in my 1986 Cougar was doing the same thing a few years ago. I replaced the thermostat, the sending unit, and it still was way up. A little research in the wiring diagram showed a "instrument voltage regulator" which actually provided the base voltage for both the temperature and fuel gauge. Replacing it solved my problem. Again, this is obscure, and if the car is newer I would bet it has no such thing, but couldn't hurt for me to mention it.
2007-03-04 22:16:30 · answer #2 · answered by gcos7 3 · 0⤊ 0⤋
you've were given a nasty thermostat. once the engine cools fairly, the thermostat could close to allow the coolant contained in the radiator to relax sufficiently. Then even as the vehicle receives warmth again, the thermostat could open. even if it truly is broken and continues to be open the fluid can pass too instantly through the radiator and in no way eliminate sufficient waste warmth. I doubt it is your fan. They not often ware out. only start up the vehicle and open the hood. even as the vehicle receives warmth you are able to be able see if the fan rotates or no longer. it truly is likewise no longer your water pump. If no coolant became operating through your engine from lack of the pump operating, vacationing some miles in line with hour does no longer generate sufficient wind to relax the engine. the reason it cools of is because the pump is operating and it truly is transferring more suitable water through your engine. Your temp gauge is measuring the water temp, no longer necessarly block temp. there is not any way the mild volume of ventilation generated from 10mph of commute could cool the water contained in the engine that instantly. it truly is why you've a thermostat. so that you'll cool the engine once you're literally not transferring.
2016-12-05 06:30:24 · answer #3 · answered by coratello 4 · 0⤊ 0⤋
If it stays at the top when the engine is obviously cold then it is the sensor that is at fault. These are designed to be "fail safe" which means if it broke and stayed at cold you would be able to overheat your car without any knowledge, so sensors are now built to show a possible overheat when there issn't one, but warning you of a problem, hence "fail safe". But do check the water levels!
2007-03-04 21:58:03 · answer #4 · answered by BackMan 4 · 1⤊ 0⤋
check the coolent level in the radiator or expansion bottle when cold. if the temperature gauge starts from cold and rises as the engine warms up it is unlikely to be faulty. howeaver check that the lead has not been rubbing on anything and shorting to earth with engine vibration. depending on how long it's been driven if it is overheating will be proportional to the damage caused to the engine.
2007-03-05 19:44:39 · answer #5 · answered by Mick W 7 · 0⤊ 0⤋
Sounds very much like a faulty temperauture sender. Especially if the gauge reads max temp as soon as you switch the inition on.
2007-03-04 23:22:37 · answer #6 · answered by howualldoing2day 3 · 0⤊ 0⤋
If it's up when the engine is cold, it might be the sensor. It's more likely the sensor wire shorted to ground.
2007-03-05 00:16:13 · answer #7 · answered by Nomadd 7 · 0⤊ 0⤋
Sounds like a radiator problem.
Have you got water in the car.
Sounds more like a problem
than a bust gauge.
Go to the garage quick
before you damage the engine
then that will cost big time.
2007-03-04 21:57:07 · answer #8 · answered by magic 4 · 0⤊ 0⤋
Sounds like the sensor is knacked if you ask me.
If you have no smoke from the engine you will be fine, but might be worth popping to your local garage and getting it replaced, as it might be masking another problem.
2007-03-04 21:51:29 · answer #9 · answered by Anonymous · 1⤊ 0⤋
Could be the thermostat or sensor, if the car is not overheating.
2007-03-04 21:54:59 · answer #10 · answered by Anonymous · 0⤊ 0⤋