Friday, November 19, 2010

How do I change the thermostat on a 1992 Chevy Blazer S10 4.3L?

I have a 1992 Chevy Blazer S10 4.3L that needs a new thermostat, and I don't know anyone that can help me, so I want to do it myself. Any help would be appreciated, I know nothing about trucks - thanks!How do I change the thermostat on a 1992 Chevy Blazer S10 4.3L?
If you follow the upper radiator hose to the engine, you will see where the hose connects to the thermostat housing, which is a flange held to the engine by two bolts. Soak these bolts with penetrating oil for a day or two before starting the job, just to be safe, they might be seized up. Have a large drain pan under the engine before you start, because engine coolant will spill. You will probably want to wear rubber gloves when doing this job, as coolant will be spilling and it's a little nasty.

First, loosen radiator cap, then remove it. Unclamp the radiator hose from the thermostat housing, and then twist and pull off the hose. You might need channelock pliers to break the hose loose from the housing flange, many times it is stuck on there good. Be prepared for coolant to spill when the hose comes off, this is where your drain pan comes to the rescue. Now tie the loose end of the radiator hose out of the way, and then remove the two bolts holding the housing to the engine ( 9/16 or 14mm wrench size ).

You will likely see ground wires attached to these bolts, if you break them, be sure to repair them afterwards, or you will have issues with the electrics of the vehicle.

Once the bolts are out, then pull the housing off the engine, you may need to use a large screwdriver for leverage to pop it off. A little more coolant spills at this time.

Remove thermostat from engine, and then clean all traces of old gasket material from the sealing surfaces of the thermostat housing and the engine. Use a razor scraper to do this, which can be bought very cheaply at an auto parts store. Use care when scraping, do not gouge or nick the metal. For stubborn gasket material, spray on some gasket remover spray and let it soak for a while. Use rags to clean and dry off the surfaces.

Once that is done, place the thermostat on the engine with the spring end DOWN. Make sure the thermostat is positioned properly in the recessed area of the engine opening. Then apply the new gasket (which came with the new thermostat) onto the sealing area of the engine. Coat both sides of the gasket with a very thin layer of silicone sealer made for this, available at the auto parts store, before you install it. Then position the thermostat housing on top, and install the two bolts, snug them both down first, then tighten them both a little at a time. This is to ensure that the cover gets tightened down evenly to avoid leaks. Don't forget to put the ground wires back on to those bolts. Then re-clamp the hose on to the cover. Top up the cooling system slowly until it is full, use a 50/50 coolant-water mix, don't just add plain water because it will weaken the strength of your coolant. Then put the rad cap back on, making sure the arrow is pointing to the overflow hose (important).

Start the engine, and let it run until it is at operating temperature. In the meantime, ensure that the thermostat cover is not leaking. When the upper radiator hose is hot, that means the engine is warmed up and that the thermostat is now open, allowing coolant to flow into the radiator.

Shut the engine off, and let it cool off for about 20 minutes or so, then carefully remove rad cap, and top off radiator as required. Top off overflow bottle if required.

Good luck with this! If you need any more info, feel free to ask!How do I change the thermostat on a 1992 Chevy Blazer S10 4.3L?
On a cold engine, loosen the radiator petcock at the bottom of the radiator. Allow about 2 quarts of fluid to drain into a pan or bucket, then close it. Follow the upper radiator hose to where it connects to the engine. This is the thermostat housing, it is held in place by two bolts, one is a stud with a ground wire on it attached with a nut. With the nut and two bolts removed, remove the housing. Inside you will see the thermostat, note how it is positioned so you don't put the new one in backwards. Remove all the old gasket material and assemble with a new gasket and tighten bolts securely, refill the radiator and run engine until the thermostat opens and top off the fluid reservoir to the proper level. Good Luck
You will have to consult with NASA, this is a real complicated problem! (not really). Ask at the parts store, read an open manual there. Do yourself a favor and don't use Dex-Cool coolant, Flush system out and use Mercedes Benz coolant. Read the GM litigation web-site about troubled GM owners!! The thermostat housing can usually be found at the opposite end of the upper radiator hose. The housing usually has 2 screws. Good Luck!!
Easy easy. On top of the engine where the radiator hose comes out you need to remove the aluminum piece it is connected to. Two bolts 13 or 14mm I believe, are all that holds it on. You may have to pry a little to get it off. underneath of that there is the thermostat. You might be able to get away with re using the old gasket if you seal it up with some silicone.

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