2005 avalanche temperature gauge does not move and reads 160 at all times. Can you advise. Jan Man.

scan the ECT if it reads wrong most time the 17 year old thermostat is bad. stuck open, missing or those crazy fail safe stat gone wild.
ect 180 to 200f is normal .
if not thermostat is first. I used and IR gun to measure the stat hosing to see if its bad, 1minutes work,
most times the gauge never fails so we do 1simple test to prove that.
scan the PCM is first.

never seen a STaT good 17 year old,
had one that told near all day to hit 180f>?
when old that do nasty things, even stick closed and warp HEADS
why risk that, attack the stat.

Popular Mechanics - Jan 1961 - Page 139 - Google Books Result

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Vol. 115, No. 1 - ‎Magazine
Right, plates of full depth and weight ... Loose hold-downs - bouncing arounddamages a battery several ways ... Excessive loads - using the starter to move thecar should be only a ... ask for a temperature-corrected hydrometer reading, which should be 1.260 specific gravity. ... All this is dependent on the individual car.

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temp gauge bouncing around before going to center? ' Yahoo Answershttps://answers.yahoo.com/question/index?qid...Sep 28, 2013 - I called my mom and we switched cars and she didn't see anything ... Best Answer: If the temp gauge is literally "bouncing around" this is more ...Why is my temperature gauge jumping?Jan 1, 2013Temperature gauge bouncing.?Dec 18, 2008What does it mean, when my coolant temp needle jumps up and ...Oct 3, 2008My car temperature gauge keeps bouncing around from cool to red ...Dec 12, 2006More results from answers.yahoo.comTemperature Gauge Jumping Around an

Well, it really depends on what temperature the car is when you start it as to which temperature area the gauge reads. Unless you mean that you always start it from the same temperature, yet the gauge reads differently each time.
Is the reading far from average? Is the gauge pointing to wildly differing areas on its scale?

If you do not know where the temperature gauge is, how do you know it is not reading right?

Replace the oil pressure gauge sending unit on the engine it is defective.

First what engine are you talking about? If it is chain driven, then it must be the 2AZ-FE engine. If so, I do not understand why the chain would need to be replaced simply because the vehicle was unused for a few years. Also, the water pump on that engine is external and is not driven by the timing chain, so I fail to understand what changing the timing chain would have to do with engine temperature unless you did not put the serpentine belt on correctly and the pump is running backwards or something.

I also do not know why you say there is a problem with the temperature when you say the temperature is in the middle-----theat is where it is SUPPOSED to be. If you think your gauge is reading incorrectly, then that is what must be diagnosed. First, you must verify that it is incorrect by measuring actuall engine temperature with an infrared thermometer next to the temperature sensor. Then you must compare the actual temperature reading with the ECT data in the engine control computer to see if the computer is reading it correctly. If it is reading it correctly and your gauge is reading too high, then there is a problem with the gauge in the instrument cluster. If the computer is not reading the temperature correctly, then you either need to replace your temp sensor or repair the circuit between the temp sensor and the computer.

The hard starting could be caused by a whole bunch of things. You could be off on your cam timing. You may have installed the Crankshaft Position Sensor Plate upside-down. It could be something like you have a tank full of rotten gas if the vehicle has been sitting for 3 years.

If you are going to a mechanic that is advising really dumb "fixes" like leaving sensors unplugged to get your cooling fans to turn on, I would highly recommend going to a different mechanic.

FUEL LEVEL SENDING UNIT INSIDE FUEL TANK COULD BE BROKEN.

The oil pressure gauge on my 2003 Avalanche reads "0" and activates low oil pressure warning. Oil level is OK and engine does not sound like one with with no oil pressure; AKA no knocks or ticking. The mileage is 50,000 on this vehicle any ideas as I with no gauge I am leary of driving it? Please advise!

it is most likey a sticking thermostat it either gets stuck closed or open in your case closed so collant isnt getting to the heater core and all you get is cold air blowing into the truck.
its a simple fix you can either do it your self or take it to a mechanic. now remember there are differnt thermostes so think about the climat you live in and get one according to that

There is a temperature sensor likely to be on your radiator. Make sure the connection is plugged in. Sometimes un-plugging and plugging it back will correct the issue. If not, you'll have to have some check if the sensor is faultly or if the electric wire is fault. You can check your fuse box. I don't think it's a fuse because other things on your instrument cluster would also not work.