Why is there oil in my coolant?

The presence of oil in a vehicle’s engine coolant can be an indication that oil from the oil circulatory system of the engine is making its way into the cooling system. This is one of the primary symptoms of a blown head gasket.

How is oil in the coolant caused by a blown head gasket?

The head gasket is a very important part within the engine which acts as a seal between the combustion chamber and oil circulatory system of a vehicle, and the cooling system of the vehicle, which should always remain separate.

When a damage occurs to the head gasket, the seal between the two systems is broken, allowing oil to enter the cooling system.

This means oil is circulating a system where it is not supposed to be, both depleting the amount of oil in the places where it is needed, but also contaminating the coolant circulating the cooling system. As the head gasket is the most common seal between the two systems to break, oil in the cooling system of the vehicle is often one of the first symptoms reported by owners of vehicles with a blown head gasket.

Why should I repair my blown head gasket?

The most likely reason for the presence of oil in the cooling system is a blown head gasket, which brings other symptoms with it that are collaboratively capable of turning a vehicle into a non-runner. Here is an indication of the other issues one can expect:

Loss of coolant

If oil can enter the cooling system, there is a high chance that water/coolant can enter the oil circulatory system. This can result in white smoke escaping the exhaust, and a creamy liquid on the oil filler cap, both of which are indicative of a blown head gasket.

Damage to other engine components

Oil is an important part of a working engine to ensure all moving components are consistently and correctly lubricated. The movement of oil into the cooling system depletes the supply of oil for lubrication purposes, causing parts to eventually build friction between each other, causing potentially significant damage.

I have oil in my engine coolant: What should I do?

If you have found oil in your coolant, take your vehicle to a mechanic to properly diagnose the underlying problem. It is a good idea to consider your options for repairing a blown head gasket as this is a likely diagnosis.

How much does it cost to fix a blown head gasket? >>