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Ask GM Tech (Cam) Your Own Question
GM Tech (Cam)
GM Tech (Cam), Chevy Technician
Category: Chevy
Satisfied Customers: 29495
Experience:  GM Grand Master Technician 2007. 14 years experience.
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GM: factory..heater..procedure for a 2008 Silverado Gas/flex 5.3L V8?

Customer Question

Do I have to drain the engine coolent to install the GM factory block heater, PN 12586687? What is the procedure for a 2008 Silverado Gas/Flex 5.3L V8?
Submitted: 8 years ago.
Category: Chevy
Expert:  GM Tech (Cam) replied 8 years ago.
WelcomeCustomer Given what style the block heater is and the location, I would put a drain bucket under the engine and pull the plug out. The plug to drain the block is also the plug you need to remove to install a block heater. The hex size is 17mm for the plug on the block. I would wait until you engine is cool before you start this. You should be able to get around everything and not have to take anything off. Please ask if you need more information.
Customer: replied 8 years ago.
So I pull the plug, drain the coolant than install the heating element, refill the coolent level and I'm done? What about the wiring? I have heard that block heaters can cause check engine lights to come on. If that happens how do I find out the error code and clear it?
Expert:  GM Tech (Cam) replied 8 years ago.
You will need to run the wiring, and if your quick, you may not even drain all the coolant. you should only use the block heater when the temp is well below freezing. The new ones have a thermostatic temp switch in the cord so it won't work until the temp is below -20 C. There should be calibration in place to allow for use of the block heaters. I have not seen a light on for the block heater being used in a long time.
Customer: replied 8 years ago.

How do I know what plug to pull out? Where is it located, I have heard they are hard to get out. Do I need to torque the heating element, do I need a special torque wrench? I have already purchased the parts but if I don't want to buy the tools to do the work will a GM dealer install the parts for me even though I bought them.

Expert:  GM Tech (Cam) replied 8 years ago.

The element goes in the back left side. See the picture below. As for torque, I would just install it and make it tight. The spec is 50 N·m (37 lb ft).

Object Number:(NNN) NNN-NNNN Size: SH

Customer: replied 8 years ago.
Can I reuse the collected coolant? Is there step by step installation instructions available online anywhere? What is the best way to route the wiring? Do you use zip ties to secure it or would they not be tough enough?
Expert:  GM Tech (Cam) replied 8 years ago.
If the coolant does not get dirty then I would re-use it. The wiring I would route with Zip Ties as you see fit. Just be sure the wire does not get routed too close to the exhaust. There should be a sheet in the package of the coolant heater with routing instructions. HERE are the replacement instructions out of the manual. Some don't apply as you have a 1500 and not the 6.0L engine.
GM Tech (Cam) and 4 other Chevy Specialists are ready to help you
Customer: replied 8 years ago.
Thanks for your help.
Expert:  GM Tech (Cam) replied 8 years ago.
Thanks for accepting. If you need more information, please ask.
Customer: replied 8 years ago.

My last question is why does it have to get so cold for the heater to work? At what temperatures does GM recommend warming engine coolant? And the procedure you sent refers to draining and filling engine coolant could you provide the same type of document for that, I've never done it before.

Expert:  GM Tech (Cam) replied 8 years ago.
GM has decided that above -20C there is no real need for the heater to be used. HERE is the draining instructions.