I have a 2005 GMC Sierra 1500 with 100,000 miles and want to change the coolant but find no radiator cap or drain plug could you please help me. thank's

its coolent temp sensor for the radiator fan check it if not that a bad radiator fan relay.

Hello there and welcome to fixya
Here is what your drain plug looks like it is located right above the lower radiator hose
also if you look at the pict of the radiator you will see it right above the lower hose

Each vehicle's radiator has a drain pet-**** on the bottom of the radiator. Generally it is on the drivers side of the radiator. Open this pet-****, drain the old coolant into a pan and dispose of properly. Close the pet-**** and refill the radiator with a 50/50 mix or antifreeze and water. The attached link explains the entire procedure.

http://www.ehow.com/video_1861_change-radiator-fluid.html

Please rate my solution. Thanks!

http://realfixesrealfast.com/realfixesrealfast.com/Heat_%26_Air/Pages/Chevy_PU_A_C_blow_hot.html

This may be your problem. The blend door may not be opening.

hello. on the drivers side of radiator is a drain. here is a picture and the instructions for draining the coolant out.

Install a tube on the radiator drain. Place the end of the tube in the drain pan.

After the engine cools down, remove the radiator cap.

Completely open the radiator drain ****.

Allow the coolant to drain from the system until the flow stops.

Place a drain pan under the block drain hole plug.

Remove the drain hole plug from the engine block.

Allow the coolant to drain from the block until the flow stops. There may be more drainage from the radiator at this time.

Install the block drain hole plug.

Close the radiator drain ****.

The drain **** should be located on the bottom section of the radiator. It can be on actual bottom or on engine side of lower section.

With engine cold, remove radiator cap. At bottom of radiator on left side (as you stand in fronof truck), there is a plastic drain plug that screws into the radiator. This plug does not look like a bottle cap, rather it looks like a large, raised tab. Turn counterclockwise to remove. Have a large pan under the truck at this location, or have the truck parked on the grass. Allow to drain completely. Dispose of the old antifreeze and do let children or pets drink it; it is deadly poison. If you want to do this right, replace the plug, refill the radiator with water only, replace the radiator cap, start engine and let run until opwerating temperature is reached (about 20 minutes), then turn engine off, let cool completely, and repeat the drain procedure. This will more thoroughly remove the old antifreeze from the system. Now refill the radiator with the proper mixture of new antifreeze and water, run engine to proper operating temperature. turn off engine and let cool completely. Add additional water and antifreeze into the coolant overflow bottle if necessary. After changing antifreeze, you may need to add more again after couple of days.

Check coolant level. Check for heat at the heater hose going from water pump to heater core at firewall. Check to see that cable is moving coolant control valve from the closed to open position. Low mileage so it shouldn't be plugged heater core.

Well all signs point to the initial stage of head gasket leak.

The piston(s) push the air/gas mixture into the coolant passage in the engine head.

You are lucky to able to catch it before oil coolant cross mix and blowing white after warm.

hydrocarbon HC test is a must!



I will not drive the truck until you check for freeze plugs leaks,change thermostat and radiator cap.



There is a very effective head gasket sealer call SteelSeal.

You will need two bottles.

After everything is under control then you must do a coolant system pressure test.
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Fixya just published my coolant system inspection tip.


If you are a DIY\'er then please take a look HERE

There should be a petcock along the bottom of the rad. Most newer rads don't have a cap the antifreeze is added through the overflow tank.