thermostat Replacement

Could be the thermostat, here is guide to help walk you through the replacement with instructions in the diagrams below to show you how on your car.

https://www.2carpros.com/articles/replace-thermostat


Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.

With the engine at full operating temp, locate the 2 heater hoses where they go into the firewall and feel them to see if they are both hot to the touch. If not too hot to hold, then you have to look at the actual engine temp and if that is up, if it is, then your looking at a restricted heater core.
If you find that they are both too hot to hold, then the heat in that vehicle is controlled by a blend door that regulates heated air flow. it is operated by an electric motor/actuator. The problem can be that the actuator is stripped or inoperative or the door itself could be damaged. This is what needs to be determined by examining the actuator and see if it is responding to heat change commands or not.
If they are both not too hot to hold on to, then you either have a restricted heater core or the system is not completely full and getting air pockets for some reason.

How to replace a thermostat on chevy tahoe 2001?
Every week I will have to refill coolant pump: It flashes out coolant from the bottom after I turn off the ignintion. Also I get display on my dashboard: "low coolant" So that makes me thing that I need to replace my thermostat. I hope that is all it is. Any other advise will be greatly appreciatted.

You have a leak somewhere if you are adding coolant/ have system pressure tested to pinpoint leak and repair the leak.

Engine Cooling problem
1999 Chevy Tahoe V8 Four Wheel Drive

im trying to change my thermostat on my 99 tahoe but cant find where it is if i could get a diagram of where it is it would be helpfull

If you follow the upper radiator hose to the engine, it will lead you to the t-stat housing. Under the housing is the t-stat.

Let me know if you have other questions.

Joe

I think the thermostat is going out in my vehicle. The temperature will go up and the air will get cold when the heater is on. The temperature will then go down and the air will get warm again. I am not sure how difficult it is to change the thermostat if that is the problem. How do you go about changing it and do you think that is the problem?

Yes, it sounds like the problem. The t-stat is located under the water outlet housing on the block. The water outlet housing is the thing that the upper radiator hose connects to from the radiator. There are two types of bolts that hold this to the block. One is a stud and one is a regular bolt. The stud has a nut on it that also acts as an electrical ground. It is very important that you remember to put this ground wire back on after you replace the t-stat. You must drain enough coolant out of the engine to get the coolant level down below the level of this coolant housing. There is no gasket for this housing but I always put a little bead of GRAY silicone on the outter edge of this housing before I bolt ot back on. If you do this, be sure to use only a little bead. The torque on this housing is only 20flbs, do not over-tighten it..good luck and let me know how you make out.

my tempurature gauge will go from cold to all the way hot then back down. also my heater will only blow out heat when the truck is running at 55 mph or more when it idles or just driving slow it will just blow out cold air i was wondering if this was the thermostat and if it is how do i change it if not what do you think it is ?

Hello and thanks for donating


If your temperature gauge is flucuating from cold to hot then back to cold it is probably not an accurate reading. This would be caused by a faulty engine coolant temp. sensor. For the A/C issue, make certain the coolant level is full.