Most car issues aren't life and death matters, although many can become more costly if you ignore them for too long. Unfortunately, some problems are more severe than others, and a few can even turn dangerous if you delay necessary repairs. While you probably know you shouldn't ignore issues with your brakes or tires, these aren't the only problems that can create hazards on the road.

If you're in the habit of deferring car repairs for too long, check out these three problems with the potential to create dangerous situations.

1. Valve Cover Gasket Leaks

Your car relies on oil for lubrication as well as its secondary cooling properties. Any oil leak can eventually starve your engine of these critical functions, resulting in substantial damage. The valve cover sits on top of your engine and uses a gasket to prevent oil from escaping. This gasket can harden and plasticize over time, creating cracks that allow tiny amounts of oil to leak out.

Unfortunately, the position of the valve cover means that even tiny amounts of oil can drip onto the hot exhaust manifold. This oil burns off, often creating visible smoke and a foul smell. While the oil loss from valve cover leaks is rarely significant, there's the potential that the oil can catch fire in the engine bay. If you can see smoke or smell burning oil, you should plan for a repair sooner rather than later.

2. Exhaust Leaks 

Loud exhaust noise is often the most common symptom of an exhaust leak, although minor leaks at the exhaust manifold can also create a ticking sound. While these noises are annoying, they don't often seem like a critical problem. Although unchecked exhaust leaks can eventually damage other components, it may seem like this is a problem you can ignore for a while.

In reality, exhaust leaks pose a substantial hazard to your health. Since your cabin isn't airtight, a leak in your exhaust can allow harmful combustion gases to enter your car. If you know your vehicle has an exhaust leak, avoid idling for long periods and keep your windows down whenever possible. Most importantly, have a shop investigate and repair the problem as soon as you can.

3. Heater Core Leaks

Your car's heating system works by routing hot coolant to a heater core inside the cabin. This design provides heat for vehicle occupants while also helping to control coolant temperatures. However, the location of the heater core means that a leak can potentially allow antifreeze into the cabin or even push coolant vapors through the HVAC system.

While coolant fumes aren't fatal, they can cause irritation and may have other harmful health effects. If you notice the sweet smell of antifreeze in your car, always have a trusted car repair service diagnose and repair the problem before it becomes any worse.