Thermostat replacent 06 GMC Sierra

[aquariuscsm]

My neighbor has an 06 GMC Sierra with the 4.3 V6. The thermostat is stuck open and her engine runs cold,of course. She went to the dealership and bought an AC Delco thermostat. I'll be putting it in for her. My question,will enough coolant leak out that I'll need to get some to replenish what leaks out,or will it be a minuscule amount not to worry about? And I'm guessing it's GM Dexcool,right?

Thanks in advance!

 

[dlundblad]

If the coolant is orange, it should be Dexcool.

You will have to drain a noticeable amount to make the fluid level lower than the thermostat housing. If you don't want to make a mess, you'll want to drain some out either through the lower radiator hose or the radiator petcock if you trust it.

 

[NHGUY]

Don't forget to purge any air out afterwards.Air pockets can cause slow heat,no heat,and overheating.

 

[Ethan1]

If you drain a gallon from the petcock into a clean container, you can reuse it. So environmentally friendly

 

[turtlevette]

Originally Posted By: NHGUY
Don't forget to purge any air out afterwards.Air pockets can cause slow heat,no heat,and overheating.


That's what the overflow tank is for.

 

[barkingspider]

U should be OK refilling with just distilled water

 

[Merkava_4]

1. Drain the radiator before pulling the thermostat housing
2. Use Dex-Cool and distilled water 50/50

 

[Ethan1]

Originally Posted By: turtlevette
Originally Posted By: NHGUY
Don't forget to purge any air out afterwards.Air pockets can cause slow heat,no heat,and overheating.


That's what the overflow tank is for.



How does the overflow tank get bubbles out of the system?

 

[SteveSRT8]

Haw. It sure is funny to hear the comments from folks who have no idea about a particular platform.

OP should carefully read the manual. On our V8 trucks you must fill the radiator through the upper hose. No overflow tank will help you later.
The danger is hot spots and head gasket failure among others...

 

[George7941]

I have the exact same truck and have had to replace the stat twice already because they started opening too early, so I speak from experience.

1) Good advice from Merk.

2) There is no rad petcock on this truck. The coolant has to be drained by disconnecting the lower rad hose. If the coolant has never been replaced, now is a good time to put fresh Dexcool in.

3) The system is self bleeding. Any air in the rad will migrate to the overflow through a air bleed hose running from the top of the rad to the overflow bottle. So all you have to do is to pour coolant into the overflow bottle and run the engine. All the trapped air will bleed out without you having to do anything.