by Harvey Birdman
Dragster engine image by Robert Young from Fotolia.com
There are many signs a car can give that would indicate an oil cooler failure. Unfortunately, these symptoms can also indicate other problems, so a visual inspection of the engine is often needed to make sure the oil cooler is the culprit. The most obvious sign of oil cooler failure is physical strain on the radiator and its associated plumbing.
If the oil cooler is failing in your vehicle, the first thing you will notice is a decrease in engine performance. This manifests itself in the form of slower acceleration and a lower possible top speed. The engine will also register a higher temperature on its heat gauge while it is running. This is because the engine is not cooling fast enough and is overheating.
Smoke is another prominent sign, as damage to the cooler can cause oil to leak out of the engine into the combustion chambers. This will cause thick, black, noxious smoke to come out of the exhaust. This smoke is poisonous and you should turn off your car once it is safe to do so. Continuing to drive the car can irreparably damage the internal parts of the engine and permanently jam it.
Vibration is another symptom of oil cooler failure, especially if oil enters the combustion chambers. This will cause mismatched explosions in the various cylinders, causing the engine to vibrate out of sync with its proper ignition speed. The vibrations can cause damage to other parts of the car if they are allowed to continue for too long. There may or may not be an increase in smoke associated with this symptom.
A distended radiator is the only sure sign of oil cooler damage, along with broken hoses that would prevent the engine from running in the first place. If a radiator has been tensioned beyond factory specifications, this can cause the frame to bend and sag. The radiator will look like a soccer ball. In the worst case, this will cause the fins to pop and look like teeth sticking out of the face of the radiator.