What causes a heater control valve to go bad

Pinch off the hose on the outlet side of the heater control valve (the hose closest to the firewall) and drive the vehicle at highway speeds. If the blower stops blowing hot air, you’ve found the problem. And, if the air conditioning runs colder with the hose clamped off, the valve is causing the problem.

Heater control valve bypass is not standard on vehicles; it is a modification. When bypass hoses are installed, the coolant in your car will always be circulating through the heater core – that means that if the core starts leaking, you won’t be able to turn it off.

To summarize, mechanical equipment such as shutdown valves, control valves, actuators, and accessories such as positioners are designed keeping in mind a plant’s life of around 25 years.

The heater control valve (sometimes called the hot water valve) is used to control the rate at which coolant flows through the heater core. The valve is located on the heater inlet hose. Manually operated systems may use a cable, a vacuum motor or an electric solenoid to operate the valve.

There are a few basic issues that usually lead to the blowing of cool air from one’s car heating system: There isn’t enough coolant in the engine. … Your heating controls are broken. You may have water leaks.

Impurities in the metal that makes up the valve causes it to break or deform under stress. Low-quality manufacturing creates a defective valve at the factory. Dirty oil causes valve wear, lowering engine compression. Defective valve springs or other parts cause valves to stick open, subjecting them to damage from …

Engine Power Loss

If your valve guides and seals are leaking, oil can accumulate on the top of the valve and cause it lose its seat or create a gap. This could cause compression issues, which lead to poor combustion and power loss. Burnt valves are another problem that contributes to power issues.

Basically, all engine valves in almost all cars and model series are built to last the entire life span of the car. Nevertheless, untimely wear can occur due to intensive use or defects and therefore the condition of the valves should be checked at regular intervals.

So, If a valve spring has broken or a camshaft lobe is worn down; it will cause the engine to create a tapping or clicking sound, due to the excess clearance. Valve train noise, is similar to a clicking sound of a, sewing machine. The sound frequency of the valve train noise is, one-half the crankshaft speed.

Broken or weak valve springs in an engine can cause many different drivability and performance problems. Broken valve springs cause excessive valve noise, compression loss and can cause severe internal engine damage. The actual breaking of the valve springs is not always the most serious consequence.

High Levels of Smoke

It’s common for some exhaust smoke to be present when you first start your vehicle, but if it begins to last longer than normal, your valve seal may be deteriorating. In addition, if you have a bad valve seal, the excessive smoke will tend to come in waves as an indicator of oil burning.

Valve Seals Replacement Cost

The cost of this replacement job will be between $900 and $1,800, depending on the make and model of your vehicle. The process of replacing valve seals involves disassembling the entire engine until you can reach the valve spring.

Cylinder compression tests are performed to identify any cylinders that have poor compression. If a cylinder has low compression, perform a wet compression test to indicate whether it’s a bad valve, head gasket, or worn piston rings causing the problem.