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vacuum operated valve in heater hose not opening


Another possibility is that the heater core is plugged. The Dex cool coolant is notorious for clumping up and clogging up the heater core when exposed to air for a while (air pockets in the system after adding in coolant)

Disconnect the 2 hoses on the firewall that run to the engine (heater core inlet and outlet). Take 2 pieces of automotive hose or whatever you can get your hands on the make a snug fit around the pipes coming out from the fire wall. run a garden hose on the right hose (outlet). Don't push the garden hose directly to the heater core. you can damage it. heater cores can handle pressure 14-16PSI on average, a garden hose can do 40-70PSI. you risk damaging it. Run the water into the hose and keep an eye out on the other one and see if coolant is flowing, you can push the garden hose closer to the outlet hose on the heater core if needed, just be careful. once you're getting clean water all the way through and no chunks or pieces are coming out. Reconnect the hoses from the engine and start it up. You'll have to add some more coolant to make up for what was flushed out.

If both heater hoses were hot chances are the heater is not plugged and there is no vacuum operated valve in the heater hoses on that model. My guess would be the temperature blend door actuator behind the dash has failed.

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โˆ™ 2014-07-11 00:53:58
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Q: You have a 2000 Blazer After installing the water pump the heater just blows cold air you have replaced the thermostat back flush the cooling system Both hoses that goes into the heater core are hot?
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Related questions

Why would a heater on a 2001 Chevy Blazer blow cold air if the thermostat was just replaced?

The heater valve could be failing to open for one reason or another.

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The thermostat on a 2001 Blazer is just inside the larger or upper radiator hose. This hose connects to the front of the engine manifold.

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Plugged radiator Defective thermostat Low coolant Defective radiator cap Water pump not circulating water fast enough Cooling fan not working

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follow the upper radiator hose to the thermostat housing on engine. Thermostat is located under the thermostat housing.

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Follow the upper radiator hose back to the engine, it is connected to the thermostat housing on the engine. The thermostat is located under the thermostat housing.

How do you find a thermostat in a 96 s10 Chevy blazer?

Follow the upper radiator hose from the radiator to the engine. It is attached to the thermostat housing. Removing the thermostat housing will expose the thermostat.

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The 2004 Chevrolet blazer 4.3 liter engine cooling system has a capacity of 4.7 gallons. The cooling system should contain a minimum of 50 percent antifreeze.

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You did not mention the engine size. Regardless, it is in the thermostat housing on the intake manifold.

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Should be a 195 degree.

Can you show a cooling diagram 1997 Chevrolet Blazer?


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195 degrees Fahrenheit.

Where is the thermostat located on 95 s10 blazer?

Follow the upper radiator hose to the engine, the thermostat is under the housing the hose connects to.

What type of coolant does a 97 Chevy s10 blazer take?

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Is it normal for a 2000 Chevy Blazer temp gauge to go to three quarters when driving in traffic even after the thermostat was replaced?

depends on what temperature thermostat was put in. come in different temperature ratings.AnswerIf you installed the correct OEM thermostat, and did not install it upside down, then no, this is not normal. You should flush the entire system, check the water pump for proper operation, clean the radiator external fins, check the operation of the electric cooling fan, (If Equipped), and make sure you bleed the system to remove any trapped air.

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Next to the thermostat housing.

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195 degrees F.