Overheating for Z28 79
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Overheating for Z28 79
So i just purchased this 79 Z28, barely getting into mechanics, and it’s overheating. The smoke was coming from the heatcore side of the engine and i heard sizzling, the smoke was clear. I filled it with water and ive got a leak coming from under the heatcore/ AC. Hopefully im saying that right, if not its essentially the box in the engine bay on the passenger side pinned against the firewall. Is there a hose from the radiator connecting to it? I haven’t completely looked at it but im assuming its coming from there.
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Re: Overheating for Z28 79
Engine coolant flows through the heater core that is in the box. Typically the box will have two hoses running to it, one supplies hot coolant from the water pump, and the other returns the “used” coolant to the pump, or another connection near the front of the engine compartment. I don't know the details of the 1979, but it should be that way. If the heater core is leaking it needs to be replaced.
When a coolant system has a leak, loss of water, and loss of cooling system pressure can cause the cooling system to overheat. Generally, mixing coolant (anti-freeze) with the water offers several benefits. First, it prevents the water from freezing and cracking the engine block, and secondly raises the boiling point of the water to insure there are no pockets of vapor in the engine that can increase the chances of overheating.
Best way to track down the leaks is a pressure test, which uses a small hand pump on the radiator fill opening to pressure the system to the rated pressure for the cooling system (look for a PSI rating on the radiator fill cap). The pressure gauge on the hand pump should stay steady at the rated pressure. If the pressure drops, there is a leak in the system.
If your car has AC, the air conditioner evaporator is also in the box on the firewall. That adds two (typically) metal pipes to supply and return refrigerant. When the AC is operating the cold evaporator causes humidity in the air to condense, and that water can drip from the heater/AC box, and drip on the exhaust, causing a sizzling and steam. That generally results from a problem with the heater/AC box drain, so you need to consider that if you have AC.
When a coolant system has a leak, loss of water, and loss of cooling system pressure can cause the cooling system to overheat. Generally, mixing coolant (anti-freeze) with the water offers several benefits. First, it prevents the water from freezing and cracking the engine block, and secondly raises the boiling point of the water to insure there are no pockets of vapor in the engine that can increase the chances of overheating.
Best way to track down the leaks is a pressure test, which uses a small hand pump on the radiator fill opening to pressure the system to the rated pressure for the cooling system (look for a PSI rating on the radiator fill cap). The pressure gauge on the hand pump should stay steady at the rated pressure. If the pressure drops, there is a leak in the system.
If your car has AC, the air conditioner evaporator is also in the box on the firewall. That adds two (typically) metal pipes to supply and return refrigerant. When the AC is operating the cold evaporator causes humidity in the air to condense, and that water can drip from the heater/AC box, and drip on the exhaust, causing a sizzling and steam. That generally results from a problem with the heater/AC box drain, so you need to consider that if you have AC.
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