How long dose it take to change a thermostat in a 2003 nissan altima 3.5 v6

SOURCE: 2003 Nissan Altima?

Where is the sensor placed on the car?

SOURCE: need to install a thermostat of a nissan altima

Dear Guest: If you have some reasonable mechanical aptitude, it is a simple task on this engine to do.
The thermostat is located near the front to the engine (the side closest to the belts) and on the side where the radiator is.
Follow the top radiator hose to the engine and you will have found the thermostat housing.
1. Make sure the engine is cool before doing this job.
2. Get a drain pan and drain the coolant from the radiator. The drain **** for the radiator is located at the bottom of the radiator. Some have an end which can be turned without tools and others require a flat screw driver to unscrew the fitting from the bottom of the radiator. Make sure you remove the radiator cap, as it will drain much faster. Once drained, put the drain **** back into the radiator. Be careful and DO NOT OVER TIGHTEN IT! It will snap off in the radiator!
3. Release the hose clamp which secures the hose to the thermostat housing and then grasp the hose at the neck where the clamp was and try to rotate the hose on the housing. DO NOT try to just pull the hose off. Break it loose first by rotating it on the housing. If it is stuck, get a small screw driver and carefully, slide it in between the hose and the housing, working it around until you can rotate the hose. At that point you can remove the hose and push it off to the side or take it loose at the radiator as well. CAUTION!!!!! the radiator tanks are plastic and will break if you are not careful!
4. There are 3 bolts which retain the housing to the cylinder head.
Typically the bolt head size is a 10mm. Using a 10mm socket, rotate the bolts in a counter clockwise direction, removing all three bolts. There are some that did use a 12 mm bolt head size. Most of the time the housing will just come loose. Sometimes, it will stick. If so, a light tap will break it loose. Pay attention as to how the thermostat is positioned in the cylinder head prior to removing it. Most of the time it will pop out easily or you can easily pry it out with a small screw driver. CAUTION!!!!
Do not damage the mating surface where the gasket seals.
Carefully clean the old gasket off. A single edge razor works fine.
5. The thermostat has a top and a bottom. If you look closely, you will see a place in the outer parameter of the thermostat where there is a small hole, often with a little metal tab which projects through the other side and is able to jiggle some. This is a small bleeder to help bleed the air trapped in the system when it is installed. This part of the thermostat must be at the 12:00 position.
Additionally, make sure the part with the hoop is sticking out toward you. The cylinder head has been machined to allow the thermostat to fit flush with it when installed properly.
6. Clean the old gasket from the thermostat housing. Nissan utilizes a liquid gasket sealer (silicon) which you apply a "SMALL" bead around the water inlet (the cylinder head side), let the sealer skin lightly and then put the housing in place making sure that the thermostat had remained seated during the installation. If it had come loose and you try to tighten the bolts, you will crack the thermostat housing.
7. When you tighten the thermostat housing bolts, there is a torque specification however most people don't have torque wrenches which measure in inch pounds. For those who have a torque wrench, 10mm bolts:56.4-66 inch lbs, 12mm bolts 12-14 ft lbs.
I have found that the easiest way to keep from over tightening the bolts is to grab the ratchet from the head and tighten the bolts because you don't have the leverage at that point.
8. Let the silicon dry for 10 minutes and and then fill the system back up with coolant. Reattach the hose and clamp being careful not to over tighten the hose clamp.
If you are replacing it, not more than a 50/50 mix. There is no special bleeding procedure Nissan has for this car. Just fill the radiator with coolant, turn the heater inside the car to the heat position to allow coolant flow into it as well, because it too is part of the cooling system in terms of coolant capacity. I usually fill the radiator until it shows 1/2 way up the tank. As the engine warms up,prior to the thermostat opening, more often than not, the coolant level will rise dramatically before it drops. Once the thermostats has opened top the system off, put the cap on and let it run for a while and watch for leaks. Take the car on a short loop and then recheck for leaks again. If everything has gone well, the temperature will read normal and no coolant will be leaking.
Hopefully this should be sufficient to answer your question.

SOURCE: How do I reset computer on 2003 Nissan Altima?

RADIO CODES KEPT AT DEALERSHIP ITS A 5 DIGIT CODE CALL THEM WITH YOUR VIN AND NAME THEY SHOULD BE ABLE TO TELL YOU THE CODE? THE COMPUTER ITSELF DOSENT MATTER IT RESETS ITSELF IF NO PROBLEMS FOUND ON REBOOT

SOURCE: nissan altima 2003 how to change engine belt

TO REPLACE DRIVE BELT YOU LOOSEN DRIVE BELT ADJUSTMENT BOLT SLIP THE BELT OFF THE CRANKSHAFT PULLEY AND REMOVE IT. IF YOU GOT A 2.5L ENGINE YOU HAVE TO ROTATE THE BELT TENSIONER TO RELEASE TENSION ON THE SERPENTINE DRIVEBELT.YOU NEED A HAYNES MANUAL.IT WILL SHOW AND TELL YOU HOW TO ADJUST DRIVE BELT AND MEASURE THE DRIVE BELT DEFLECTION USING A STRAIGHT EDGE RULER.

SOURCE: Nissan Altima tring to change my transmission fulid and filter

thats why you have to remove the frame and for this you need an engine support and the average mechanic will charge you arround 100 bucks to do it
some rental stores have them some dont good luck eithor way you go but for god sake be carefull