My infiniti m35 2006 temperature guage keeps shooting up to hot...I recently replaced the radiator and thermostat...they used a 170degree thrmostat..does that make a difference? Also when they first change it it was still going hot...They put a radiator cap off of another car and then it was fine...I jus came back from a trip 580 miles one way and had no problems out of it..now three days later its doing the same thing again..but there arent any leaks

Infiniti and Nissan has with other vehicles require vacuum fill the cooling system because the air is trapped inside the heater core cannot be removed without using a vacuum Phil or connect the vacuum and let it run for 510 minutes and then it will be good make sure the radiator cap is freshAlso keep the mixture at -36° which is 50-50 for Green or not mixed when it’s blue

Lack of prestone

I would assume it is because either a) your engine is getting very hot, or b) your temperature sensor is going bad. The way to test would be to use an infrared thermometer to see the engine temperature. Does the car shut down on your while you are driving?
If the engine is getting very hot, it is probably because your coolant isn't flowing properly or your radiator is blocked by a plastic bag or something.
Once you confirm that your radiator isn't blocked, check the level of the coolant in the reservoir and in the radiator. It should be full to the top of the radiator. If not, add coolant (you should check for a leak if it is seriously low).
If there is enough coolant, you may want to check that your thermostat is opening. This would be as simple as checking if both the top and bottom radiator hoses are getting hot. If they are both hot, then your coolant is flowing through the thermostat.

Check these three things (radiator not blocked, radiator has enough coolant, and both top and bottom radiator hoses getting hot) and then reply with what you have found.
My bet, without seeing the car, is that your thermostat is stuck closed and it needs to be replaced. This is a $10 fix. Buy a new thermostat at Autozone or another parts store, and replace the old one (I'll explain how if it comes to this.)

Yes, the temperature gauge should normally stop in the middle, between the cold and hot points on the gauge. When the engine is cold the thermostat will be closed and will keep recirculating the coolant in the engine block until it warms up sufficiently. Then the temperature of the warm coolant will cause the thermostat to open the channel to the radiator to get rid of excess heat, which should stop the coolant from over heating. So the effect of the thermostat keeps the coolant at a fairly stable temperature. When the coolant runs low, it can't transfer enough heat to the radiator and the coolant and engine then over heats. Watch for radiator leaks under your car after you have been driving it. If the coolant goes low again fairly quickly you could have a leak in a hose or the radiator itself.

Have you checked the engine temperature when the gauge shows fully high if it is true message and not lying and the problem is the temperature gauge? Since this happened stop the car open the bonnet touch the radiator hoses and even with off running engine touch the vents of the radiator to all surface and see it the temperature is everywhere the same.

FLUSH RADIATOR, HEATER CORE AND ENGINE BLOCK.ADD 50 / 50 ANTIFREEZE AND WATER ALSO REPLACE RADIATOR PRESSURE CAP.IF TEMPERATURE GAUGE STILL STAY HIGH THE ENGINE COOLANT TEMPERATURE SENSOR COULD BE FAULTY.

Sounds like thermostat went bad. That would explain cold one side/hot other. I'd start there. Good parts sources - BavAuto.com or PelicanParts.com

Flushing the radiator, replacing the radiator cap, adding new coolant, replacing the sensors and a new thermostat solved the problem. Probably didn't need to do all of these things - but since we just purchased the truck, and given the fact that is probably hadn't been done in a while, we chose to do all of these things (which really didn't cost a whole lot), it's running like a charm now.

replace thermostat.feel top radiator hose and bottom radiator hose if they both should be hot 10-15 minutes.if not replace thermostat.

you need to make sure you have enough coolant in the radiator and oil in the car its better to take it in before you do some damage even that the engine is not hot its heating up inside very fast