Most people leave checking the coolant to the mechanics while they fill up the gas tank, which is a big mistake. Just because you don’t see any coolant on the ground does not mean there is nothing wrong.
Your coolant could be leaking from numerous places, and if you are not looking for the signs and warning signs, you’ll be looking at an engine that is always running a temperature too hot!
So, where is that coolant going, and what can you do about it? Read on and we’ll help you understand!
Common Causes of Losing Coolant (But Don’t See a Leak)
Whether you drive a Subaru or a Lexus, your car needs antifreeze. So, when your coolant disappears, you should figure out why quickly and eliminate that cause.
Below are the three most common reasons your coolant reservoir is empty over and over again.
#1. Head Gasket.
This is probably the first thing a mechanic is going to tell you the problem is. Head gaskets are notorious for leaking, but they leak everything right into the combustion chamber instead of onto the ground.
While you won’t see any visible signs on the ground, it will be pretty obvious if you check out the exhaust.
You are going to have a huge cloud of white smoke pouring out of the exhaust if you have a blown head gasket.
This is because, compared to gas that leaves mostly clear or black exhaust fumes, coolant burns white, regardless of any coolant color.
Expect that your temperature gauge is going to be way out of the normal zone, too.
On top of that, you will probably see oil in your coolant overflow tank or coolant in your fucking oil.
But in some cases, an internal leak like a head gasket may be relatively small, so you won’t experience leaks and no overheating simply because the coolant is temporarily keeping the cylinder temperatures in check.
But once you lose enough coolant, you will have overheated regardless.
#2. Radiator Cap.
If you’ve ruled out an internal leak, that means that your engine is burning the coolant somewhere else. The most common area is the radiator cap.
The radiator cap holds the pressure inside the system, but if it’s not sealing properly, then some hyper-pressurized coolant is going to escape as steam.
When your engine has warmed up, you will be able to tell if steam is escaping from your radiator cap by merely looking at it. You shouldn’t see any steam or smoke coming from the cap, and if you do, then you’ll need to replace it.
#3. Leak onto the Engine Block.
Even though a leak onto the engine block will typically leave a puddle directly under the vehicle at some point, if it is leaking directly onto the top of your engine and puddling up until it warms up, it may burn the coolant off before it gets to the ground.
While rare, it can happen, and just like a bad radiator cap, a tell-tale sign is smoke in the vicinity of white smoke right out of the engine bay while the engine is running.
Step-By-Step Troubleshooting Guide
When looking for the source of the coolant disappearing, discovering the reason typically isn’t the hard part. If you follow our troubleshooting guide below step-by-step, you should be able to discover your issue, without even taking it to a shop!
#1. Check the Exhaust.
It is, by far, the most common reason for coolant burning off, and one of the easiest things to identify.
All you have to do is look at the exhaust while the engine is running. If there is excessive white smoke, then you have a blown head gasket.
However, just because there is some white smoke, it does not mean you have a head gasket. Although there has to be excessive white smoke.
In cold weather, your vehicle will produce more visible smoke than if it were warmer out. This is completely normal.
#2. Check the Oil.
If you looked at your exhaust smoke and cannot determine whether or not you have a blown head gasket, then have a look at your oil. Simply pull the dipstick and see if your oil level is rising over time.
When you have coolant in your combustion chamber, it does not always get completely burned off. Therefore, if it is left in your combustion chamber long enough, it will eventually work past the O-rings and end up in the oil pan.
If you are an advanced mechanic, you may be able to tell merely by smelling and feeling oil, while novices will usually just keep an eye on the level to see if the oil level does indeed rise.
If you have coolant in your oil, you most likely have a blown head gasket and need to take it to see a mechanic to have a look at your engine.
#3. Check for Engine Smoke.
If you have engine smoke, that is a sign you have a problem. Attempt to source the smoke; however, if it is white, then it is a sign of coolant.
If you don’t have a visible leak underneath your engine, then have a look at your radiator cap, and then anywhere along the top or sides of your engine. If you find any antifreeze, then you have located the problem!