What Happens When There is Coolant in Engine Oil and What You Need to do

Differences Between Antifreeze and Engine Oil


Antifreeze is an additive that lowers down the freezing point of the water-based liquid.


On the contrary, oil is another fluid used for the engine to work properly. Now, you can guess that these two being different liquid and operating for distinct purposes. They can cause disaster in the components of the car after getting mixed.

Differences in Chemical Structure

The differences in them are not just the functions but the chemical structures too. This emphasizes the fact that they should not get mixed. Even though they are mixed, you do not need to panic.

This whole article is based on the idea of what should you do when there is antifreeze in the oil.

There are few things you need not panic.


What Happens If There Is Coolant In Oil

It is okay that the coolant has been mixed with the engine oil. Though it is a matter of concern you have to keep calm since being worried will only steal away the solutions.

The mixture of antifreeze and oil will not blast the car but we will be estimating the danger and loss. There is another situation arises when the engine is totally oil-free or without lubrication, what if antifreeze is added? The outcome would be the loss of your engine simple is that. However, if the coolant is added with oil it would be pretty fine? Yes? or No?

The answer lies both in Yes and No. because there is still an issue to be addressed.

Different Structures of these Chemicals Create Problems

Structure of Engine Oil

The engine oil is thicker and denser, due to its function it is designed so, to coat the engine surface while moving. This coated surface prevents the damage to occur as a result of friction. It also helps in the reduction of excess heat produced due to friction force in the engine parts.

Structure of Coolant

Whereas, antifreeze is very thin and fluid liquid. It is structured to reduce the freezing temperature and ultimately raising the boiling temperature. For this purpose it is poured into the coolant system, which protects the coolant system damage in extreme weather conditions: for instance, the frozen pipes won’t get burst similarly, excess engine heat is avoided for coping the lower and even lowest temperatures.

Chemical Reaction Between Both Chemicals

The chemical reaction between the two chemicals leads to lowering the effective functioning of the engine oil, because it causes in the breakup of the engine oil molecules, resultantly the engine parts are less lubricated.

Moreover, a number of ingredients the coolant contains which are harmful to the engine parts, therefore a close contact must be avoided. For this reason, antifreeze should be removed from the engine as far as no longer in use,

Now, what if antifreeze is noticed in the engine oil? After having knowledge of the function of both the liquids, to be more specific, what should be done on starting the vehicle and antifreeze is found present in engine oil?


What Should Be Done If the Engine Of The Vehicle Does Not Start?

It is quite tense when you are stuck with the situation: antifreeze presence in engine oil and the engine doesn’t start.

Reasons Why the Engine is Not Starting

Most probably it happens due to two reasons:

  1. Carelessly you have poured the coolant in engine oil
  2. Accidentally it is necked down to engine oil.

Fixing These Issues

Whatever be the cause here pretty simple solution is outlined:

  1. Don’t panic it is not a big deal, because its a common mistake committed by many drivers many times.
  2. You may find enough reading material including this one where we have facilitated you with the solution.
  3. You need not start the engine at any cause; if you did so then the only solution left will be to remove the coolant from the engine oil.
  4. If you have not started the engine then it means you are pretty smart and genius by saving money and time.

Now follow the below step by step instructions:

  1. When you came to know that the antifreeze and engine are mixed so don’t do anything. Anything means anything, leave the care for an hour or more, because the two liquids don’t get mixed easily, therefore the coolant gets to the bottom of the oil pan, due to its thinness.
  2. Once the coolant is settled into the oil sump, remove the sump plug and drain the content into a bucket or a drain pan. The drain shall continue till clean oil is seen.
  3. Now pour some more fresh oil _ not the antifreeze once again.
  4. For safety purposes, replenish the oil now or after sometimes days.


What Should Be Done In Case Vehicle Engine WAS Started?

There may be a time when you have started the engine, while antifreeze in the oil, you should be enough sure to see some highlighted indicators of a problem.

Diagnosing the Leakage of Coolant into Oil

You may diagnose the leakage of antifreeze into oil by two indicators:

  1. Brownish bubbles of crust dried up as residue on the dipstick
  2. Chocolate milk may be seen when the oil is drained in the oil sump.

Fixing These Issues

  1. Since the coolant is mixed with the oil so without any time taking straight away take out the all, or drain all at once.
  2. A full oil change must take place, in fact, change the filter as well.
  3. Normal car drive to be made for a day or two
  4. Second oil drain must be done, replenish with the fresh oil and filter change again.
  5. A permanent solution to be made for avoiding the mixing of both the liquids by checking it from a mechanic.

This seems quite irritating yet, timely diagnoses and fixing may avoid a big loss of changing the vehicle engine.