It’s caused when your coolant gets low. Fix your leak and bleed the coolant system. Or you can check this theory by filling and bleeding the coolant system now. If it works, it will be ok until the coolant system gets low and causes the air bubble again.

Hot coolant from the engine passes through a heater core, which looks and functions a lot like a small radiator, and a blower motor forces air through it. It’s also the reason that a plugged heater core, stuck thermostat, or air in the cooling system can all cause a car’s heater to blow cold.

Method 1 of 4: Check proper fluid levels

1. Materials Needed.
2. Step 1: Verify radiator coolant levels.
3. Step 2: Verify reservoir bottle fluid levels.
4. Step 1: Turn on the engine.
5. Step 2: Check the temperature change on the dashboard.
6. Step 1: Locate the fan vents.
7. Step 2: Check for a broken or faulty fuse.

You may have a clogged heater core that may be prohibiting the outer linings of the heater core to get hot. As you know, the heater core is a series of tubes that the coolant runs through that generates the heat from the warm coolant after circulating through the motor.

When you rev your engine, you place additional and unnecessary stress on your car and its engine. This is imperative when it’s cold outside—revving your engine before it has had time to warm up is especially damaging, as the engine’s oil hasn’t had sufficient time to circulate and properly lubricate your car.

Let the engine run for 30 seconds. That’s all it takes in most vehicles that are 30 years old or newer. If it’s extremely cold and your vehicle is covered in snow or ice give it a minute or two longer to warm up.

Wrong! Warming up your car in winter before driving it is actually terrible for your engine. According to Popular Mechanics, driving your car right away is the fastest way to warm up your engine, and will actually prolong the life of your engine instead of letting it sit idly before driving.

Short answer: yes. Engines wear according to how they’re driven. If you don’t do the occasional spirited run, then your engine will wear tight and slow as opposed to loose and fast.

Answer is….its ok to rev you engine in neutral/park. Just not when its cold and dont hold it on rev limiter! Try not to, because free revving can damage the engine.

Short answer: Yep. Redline your engine with impunity if you so desire. Banging off the rev limiter is bad, revving the snot out of an unloaded engine is bad, and riding around with the engine at full song for no reason is… well, not bad, but it’s not great.

Do Cars Need Rest? Cars do not need to rest under normal conditions. As long as they don’t heat up you can continue driving. It’s important to monitor the temperature of the engine to make sure it doesn’t overheat in very warm weather conditions.

As a general rule, it’s best to take a break of at least 15 minutes every two hours, and to not drive for more than eight hours in a day, to ensure you stay alert and avoid the associated risks of driving for too long without a rest.

Revving the engine won’t speed up the process. In fact, that could cause easily avoided damage. Cold revving causes abrupt temperature changes that create stress between the engine’s tight-fitting components.

However, there’s no need to worry. Redlining will not damage an engine or cause it to explode, no matter how cruelly you treat it. Therefore, revving the engine to its maximum speed several times a week is not a problem. Just remember never to do this while the engine is still cold!