How Much Coolant Loss is Normal? (The Answer)

how much coolant loss is normal

One thing a lot of drivers ask is – is it normal to have a coolant leak? I mean, if the leak isn’t that bad, it isn’t a problem, right? This is not true. If a car’s coolant system is working properly, there’s no reason why there should be a coolant leak.

You know what it looks like. You come out to your car on a hot day and find a bright green puddle underneath your car. Or, worse yet, you don’t see it and drive away. If you have a big leak, there’s a problem.

You might think that a coolant leak can only affect your heater and A/C. That isn’t true. Not only is a coolant leak a sign that there’s a bigger problem. But it can also lead to other problems with your engine that can cost thousands of dollars to fix.

Rather than let it get to this point, just take a few basic steps to make sure your coolant leak doesn’t turn into something bigger. Here, we’ll talk about what causes a coolant leak and what you can do to inspect your coolant system. If you’re like most of us, you’re not a licensed mechanic. So, do what you can. But if you get in over your head, don’t fret. Just take your car to your local mechanic and let a professional take a look at your cooling system.

What are the Major Causes of a Coolant Leak?

coolant leak under car

Like we said before, there really is no acceptable level of a coolant leak. If it’s negligible, you won’t even notice it. For example, if the temperature is really high or really low, you might see your engine working overtime. But these days are few and far between. If you see that your radiator is constantly leaking fluid, then it’s time to get it checked out.

The major causes of a coolant leak are:

  • A faulty radiator cap
  • Worn out or torn radiator hoses
  • Overfilling the coolant system
  • A leak that comes and goes
  • A cracked engine block or cylinder head
  • Blown head gasket
  • Towing unusually heavy loads

If you notice any of these things, it could be what’s causing your coolant leak. Aside from the towing issue, it’s a good idea to take your car to your mechanic. Let them check to make sure there isn’t a bigger problem. For example, if you have a blown gasket, it’s only a matter of time before your car’s engine seizes up. And, if you don’t get your radiator checked out, you may find yourself stranded on the side of the road.

How Big a Problem is it to Have a Coolant Leak?


While there are a lot of other worse problems you could have with your car, having a coolant leak isn’t a good thing. This is why it’s a good idea to have it checked out sooner rather than later. It can eventually destroy your engine. It will certainly destroy your radiator and coolant system.

A small leak is almost always going to turn into a bigger leak. It’s better to catch it when it’s a small leak. This way, your problem is cheap and easy to fix. The worse it gets, the more it’s going to cost to fix. The worse the leak, the better the chance that your engine will overheat. Your car overheating will ultimately lead to a total engine breakdown.

Are You Overfilling the Coolant System?

There is a chance that you’re putting too much coolant in your system. Just like over-watering a plant can kill it, overfilling your coolant system can be dangerous. What you should do is follow these basic steps when it comes to refilling or topping off your coolant:

  • Check your car’s manual to see where the coolant goes
  • Look for the COLD/MIN line
  • Just fill it to under the filler neck
  • Make sure you close the radiator cap
  • Check that all of your hoses are nice and tight

If you do these things, you won’t have to worry about overfilling your coolant. However, this isn’t the only thing that can cause your coolant to leak. If your car is overheating, it’s a sign that something’s wrong.

Is Your Coolant Loss Due to Your Car Overheating?

If your car is overheating, then the coolant leak may be the least of your worries. You need to get to the core of the problem. Your mechanic can check to see what’s causing your engine to overheat. They can also look to see if there are major or minor leaks in your coolant system. If there are, it’s cheaper and easier to get these leaks fixed than it is to get an entire engine rebuild later on.

The thing about your engine and your coolant system is that they work together. It’s a chicken and egg problem. Your car overheating can cause a coolant leak. And, a coolant leak can cause your engine to overheat. This is why it’s a good idea to look for the following signs:

  • Is there enough coolant in the system?
  • Check your drive belt. Is it properly adjusted? Is there any wear and tear?
  • Check your serpentine belt. Is it noisy or worn?
  • Do you have a blocked radiator grill or core?
  • Do you have a faulty cooling fan?
  • Is your radiator cap cracked or damaged?
  • Do you have a faulty thermostat?

If you notice any of these things, you need to get your car repaired as soon as possible. It’s cheaper and safer to have your mechanic fix these problems early on. If you wait too long, not only will the problem get bigger, it will become more expensive to fix. If you notice a leak in your coolant system, you need to get to your local mechanic right away. The longer you wait, the worse the problem will become.

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