My temperature gauge doesn't get read normal it reads below normal and when it has no water in it and it gets hot it reads normal but doesn't go any further I already changed the coolant temp sender and sensor... any ideas? I had the top end rebuilt and a aftermarket radiator put in....

There could be a few different issues that could cause the temperature gauge on your 2008 Ford Focus to read hot when the engine is not actually overheating. Here are a few things to consider:

Failed thermostat: The thermostat is responsible for regulating the flow of coolant through the engine. If the thermostat is stuck in the closed position, it could cause the temperature gauge to read hot even though the engine is not overheating.

Failed temperature sensor: The temperature sensor sends a signal to the temperature gauge to indicate the engine's temperature. If the temperature sensor is faulty, it could cause the temperature gauge to read hot even though the engine is not overheating.

Wiring issue: If there is a problem with the wiring that connects the temperature sensor to the temperature gauge, it could cause the gauge to read hot even though the engine is not overheating.

To determine the cause of the issue, it may be necessary to perform some diagnostic tests and possibly replace some components. A mechanic or a professional auto repair shop will be able to diagnose the problem and recommend the appropriate repairs. It's also a good idea to keep an eye on the engine temperature and take note of any other symptoms or issues you may be experiencing. This information can help the mechanic diagnose the problem more accurately

It sounds like you may be experiencing an issue with the temperature gauge in your Buick Lucerne, as well as possibly an issue with the engine. If the temperature gauge is reading below the "C" (which likely stands for "Cold"), it could indicate that the engine is not reaching normal operating temperature, which could be caused by a number of factors such as a low coolant level, a faulty thermostat, or a malfunctioning water pump.
If the engine light has also come on, this could indicate that there is a problem with the vehicle's emission control system or another component of the vehicle. It is important to address this issue as soon as possible, as driving the vehicle with an overheated engine or other malfunction could potentially cause further damage.
To troubleshoot the problem, you should first check the coolant level in the vehicle to make sure it is at the correct level. If the coolant level is low, you should add more coolant to the system according to the instructions in the owner's manual. If the coolant level is normal and the temperature gauge is still reading low, you should have the vehicle inspected by a qualified mechanic as soon as possible to diagnose and repair the problem.

Reasons the Temperature Gauge Reads High

If the temperature gauge reads high, it could mean your engine is overheating. Another reason your reading might be high is you could be losing coolant. A small leak or evaporation may cause your radiator to slowly lose coolant. A third reason your temperature gauge reads high could be because the thermostat is broken. If this is the case, you may need a coolant temperature switch replacement. The last reason the temperature gauge could read high is because of a water pump, or water pump gasket failure. If the water pump is malfunctioning, it may need to be replaced by a professional.

What to Do If Your Temperature Gauge is High

If your temperature gauge is reading high, it means your car is overheating. This is a very serious matter and you should never drive an overheating car. If your car starts to overheat, shut off the air conditioner and open the windows immediately. If this does not reduce the overheating, turn on the heater as high as it can go. If this still doesn't work, pull over on the side of the road, turn off the engine, open the hood carefully, and wait until the vehicle cools down. Never open the radiator cap while the engine is hot - coolant can spray and burn you. Once the vehicle has cooled, take the car to a mechanic right away so they can diagnose the problem. Cars are especially susceptible to overheating in hot climates, like what's common in cities like Los Angeles, Phoenix, Las Vegas, or Atlanta.
The temperature gauge is an important tool in your vehicle that shows the temperature of your engine's coolant. Contact YourMechanic and have your car inspected for overheating if it reads too high, as this can cause serious problems...

Reasons the Temperature Gauge Reads Cold

On most vehicles, the temperature gauge reads cold until the engine has run for a few minutes. If the temperature gauge still reads cold after the engine has warmed up, the gauge may simply be broken. Another reason the temperature gauge could read cold is if the thermostat in the vehicle stays open. With the thermostat stuck open, the engine can be overcooled, causing a low temperature reading. If this is the case, the thermostat may need to be replaced.

engine - Car temperature displaying below Cold or just ...

mechanics.stackexchange.com/.../car-temperature-displaying-below-cold...

Jun 25, 2012 - Today I was boiling inside my car as it was a very hot day and my ...cold, it almost never goes up to even 1/4 of the temperature gauge, the ... Where I live, it's hot enough that even with the thermostat wide open the engine won't stay at C.. ... How to Match Skin Color Between Pictures Of The Same Person In ...

What does it mean when my car's temperature gauge is halfway ...

https://answers.yahoo.com/question/index?qid...

Aug 23, 2011 - I think my temperature gauge is usually all the way to the left, which I think is "cold" (okay). ... before steam poured from under the hood of my car and I had to pay $217 ... Why does my A/C stop blowing cold & my temperature gauge goes toHOT? ... But the battery won't keep a charge after sitting over night. my temp gauge always stays on cold. never moves.? ' Yahoo Answers
Mar 28, 2014
My car temperature gauge started going crazy and it doesnt even ...
Nov 10, 2011
My engine temp gauge reads below normal, close to cold, even ...
Mar 23, 2007
my temperature gage on my car keeps going up and down.. does ...
Feb 15, 2007
More results from answers.yahoo.com

No it is not. Is your engine running hot according to temperature gauge? That is the coolant return which means the coolant was too hot coming out of engine and returning to rad for cooling. You obviously have a cooling system problem whether water pump, thermostat, rad, cooling fan etc. Give more details on what happens when starting from cool, and sittting idling, driving etc as far as temperature gauge reads and how hot engine gets. Be careful not to overheat engine, if you haven't already

Pull off the negative battery cable and unplug the sensor. See if the gauge needle returns to normal. Try tapping on the cluster to unstick the needle. No luck? Replace the temperature gauge.

How do you know it gets hot? Are you going by the temperature gauge on the dash? Or have you checked under the hood and found out the engine really is running hot? ...Reason I ask is, something just doesn't sound right in your description. After just 5 minutes from starting and driving away, the engine would not yet be at normal operating temperature. That would explain the heater not yet warm. But the temp. gauge says hot?
If so, I would replace the temperature sending unit on the engine. the one for the dash gauge, and see if that was the problem-not reading the temp. accurately.
Couple of other things: Are you sure you got all the air out of the coolant system? Start the car with the radiator cap off and let it run until the engine is warmed up fully, then shut it off and install the cap. Does your reservoir tank stay about half full where it should be, between the full-hot and full-cold marks?
If your problem persists. I would have the coolant system pressure tested, and see if you could get a true temperature reading of the coolant when it seems to be running hot.
Good luck.

Did the engine overheat before the water pump was replaced? If so, you may have a warped cylinder head and/or blown head gasket.

Was the radiator full of rusty-colored liquid before you flushed it? If so, your radiator is probably restricted with rust deposits in the cooling tubes. Flushing WILL NOT get this stuff out. The radiator MUST be replaced if this is the case. Your heater core is probably not in real good shape either, so you should be expecting some heating problems this winter.

If the above is not the correct answer, then you should check to make sure the temperature gauge is not "LYING" to you. This could be caused by a defective gauge, a bad temperature sending unit, or faulty wiring.

The way to check this is with a scan tool that can read engine data and an infrared thermometer. While reading the coolant temperature data from the computer, check the cylinder head temperature with the infrared thermomometer. The readings you get should be within 5 degrees (F) of each other. If the computer data does not match the thermometer within the 5 degrees, then the sending unit for the computer should be replaced.

Then look at the gauge to see if the gauge reading is appropriate to the temperature readings that you took. Normal operating temperature is between 190 and 230 degrees. This should place the gauge at slightly to the right of center to about 5/8ths of the way to HOT. If the readings you took are OK and the gauge is reading higher than this, then you should try replacing the temperature sending unit for the gauge and see if that fixes the problem.

Please note that there are TWO temp sending units: One for the gauge and one for the computer.

hi the temp gauge should sit in the lower quarter of the gauge, it has to be a faulty water temp sensor as anything else would cause it to over heat badly

just below the filler cap there is a plastic type nut with a wire on it, the temp sender, change it as these tend to go wonky