How to Test Your Car’s Oil Cooler for Leaks & Other Troubleshooting Tips

Your car has a lot going on beneath the bonnet. Behind the scenes, many parts are working together to make your car go—but these parts would be nothing without the lubricating touch of engine oil. Oil quite literally smooths along all operations and it’s an excellent conductor of heat. On the one hand, this is an essential property for an engine lubricant. You need a liquid that can withstand high temperatures without evaporating. On the other hand, oil is also prone to overheating and has no way of regulating its temperature without assistance.

This, in a nutshell, is why oil coolers are so important. Without one, your car would overheat very quickly. But can a bad oil cooler also cause overheating? The answer is yes. Although the absence of an oil cooler would be a worst-case scenario, the next worst thing would be driving with a failing oil cooler. In the interests of safety, it’s critical that you know the signs of an oil cooler that’s on the way out so you can attend to the problem as soon as possible.

What Causes Oil Cooler Failure?

Truth be told, all oil coolers will wear out eventually. They have a service life like everything else. The only way to combat the inevitable is to follow maintenance procedures. That said, if an oil cooler is on the way out, it will tell you. Here are some signs to look out for.

Leaking Oil

If your car is leaking oil, that’s probably the number-one sign that the oil cooler is closing up shop. So, what causes an oil cooler to leak? An adapter holds your car’s oil lines and oil cooler in place, and if the adapter fails, that’s when it all unravels. If you find yourself wondering, ‘how can I tell if my oil cooler is leaking?’, you need only check beneath the car for anything ranging from a slight puddle to a steady stream of oil. However much oil the adapter forces out of the cooler and engine is directly proportional to the extent of damage it’s sustained.

On the other hand, oil leaks can also indicate that the oil has shown up in the car’s cooling system. Regardless of how the problem manifests itself inside the car, though, the point stands that leaking oil is a sign of trouble. You will likely require a professional to fix your leaking oil cooler, if not a complete oil cooler replacement.

Leaking Coolant

Similar to leaking oil, leaking coolant is a sign that the oil cooler is failing. This substance can, too, manifest as something as minor as a miniature puddle or as large-scale as a consistent stream beneath the vehicle. If your coolant’s leaking, your engine is at risk of overheating and it’s time to call in a professional.

Engine Underperformance

Engines need cooled oil to run—and if it’s coming in hot, it’s also going to heat up the engine. The consequence of this is often that the engine ‘pulls back’ on performing its functions in full. For example, if your car isn’t accelerating like it used to, that may be a sign of oil cooler failure.

Black Smoke

If you find that your car is creating smoke as you drive, it’s time to stop driving before you damage any engine components. Black smoke often indicates that oil has got into the combustion chambers, and this is what happens when the oil cooler fails.

Bad Vibrations

Good vibrations in a car is, ironically, the complete absence of any physical vibrations. It’s when a car actually starts vibrating that those good vibrations go bad. When oil gets into the combustion chambers, black smoke isn’t always the only tell. Vibrations can also happen due to explosions that occur in some of the car’s cylinders. As is the case with black smoke emissions, if you notice any vibrations, you should stop the engine to prevent further damage to other vehicle components.

Swollen Radiator

When humans are unwell, sometimes their body parts swell up. Similarly, a swollen radiator is a sign that something is up in your car. If your radiator’s swelling, that’s one of the more obvious signs that your oil cooler’s failing. Furthermore, if you’re finding broken hoses that can hamper engine performance, that pretty much confirms it.

A Coolant & Oil Cocktail

Let’s make one thing clear: coolant and oil should never combine. While the two have a symbiotic relationship—where the coolant flows around the tubes to regulate oil temperature—they work in parallel and never the twain shall meet. When these two combine, however, they can damage and even stop an engine. This happens when the oil cooler fails, puts pressure on the cooling system and forces coolant into the oil pan.

How Can I Tell if My Oil Cooler Is Leaking?

If you’re unsure if your oil cooler is leaking, there are ways to know for sure. Why not put the following test to the test?

  • Unbolt your oil cooler from the engine bay.
  • Place a dust cap and clamp onto an oil cooler nozzle.
  • Connect a 2.5cm hose to the remaining oil cooler nozzle.
  • Use adapters to connect and provide air to the hose.
  • Submerge the oil cooler in water.
  • Apply pressure to the oil cooler using approximately 0.8 bar of compressed air.
  • Replace the cooler element if you see air bubbles emerging from the oil cooler.

Alternatively—as we have suggested throughout this blog post—you can also seek assistance from a professional mechanic who would know best. In any case, if you suspect your oil cooler is leaking, it’s critical to resolve the issue one way or another.

Can I Drive With a Bad Oil Cooler?

Although it’s technically possible to drive with a bad oil cooler, we would strongly advise against it. Bad oil coolers are ticking time bombs that can wreak havoc on your engine and potentially cause it to stop. Obviously, this is a large safety risk, and so the best foot forward is to replace your oil cooler—potentially with a remote oil filter kit from Proflow.

Trust Proflow

At Proflow, we’re auto enthusiasts who have all the parts you need for a smoother ride. Of course, oil coolers fall among these parts, and they’re not only high quality but also super affordable. If you need to update your oil cooler or replace it altogether, you know where to find us. Proflow is the way to go! Shop our collection online now.