Can engine oil affect the car’s transmission?

Using the wrong fluid in your vehicle can cause a wide range of unnecessary car problems. From causing the transmission in your vehicle to slip while driving to causing the car to overheat, the results can vary widely from irritating to deadly.

Therefore, if you choose the wrong types of fluids for your vehicle, you may be required to pay a very expensive repair bill to correct the damage.

Now that you know the potential problems that can occur, let’s open up a more detailed discussion on topics like using car engine oil in your car’s transmission.

Can motor oil affect or ruin a car’s transmission?

Typically, based on the severity of the damage caused, your mechanic may not be able to reverse the damage to your transmission, even if the mechanic flushes the transmission of the bad engine oil.

And, then replace this bad oil with the best brand of transmission fluid on the market today. This is because adding motor oil or brake fluid to your transmission can completely destroy the transmission and its proper functioning.

Can engine oil get into the automatic transmission?

If for some reason the engine oil leaked in a large quantity all over the engine and you may wonder if that also affected the transmission, then you should know that it is next to impossible for engine oil to leak into an automatic transmission.

Therefore, if there is motor oil in your transmission, it is most likely because someone has mistakenly poured motor oil into the transmission instead of transmission fluid.

In fact, in all actuality, this type of mistake is more common than most people may think. This is also why car owners should always pay special attention to their car maintenance care and their own practices.

For instance, do not be too quick about pouring motor oil or transmission fluid into your vehicle unless you double-check the label on your containers first.

Other than that, the transmission itself is very well sealed so an accidental leak of a large quantity of oil most likely does not affect it.

Additionally, you need to make sure that your mechanic is not only experienced and reliable but also responsible enough to take the same care that you would for your own vehicle.

In this way, you can make sure that these common expensive mistakes can be avoided altogether.

What happens if motor oil gets in the transmission fluid?

As mentioned before, motor oil in your transmission can cause your car’s transmission to malfunction. However, if the accident is discovered early enough, you may be able to fix it before severe damages are done.

For instance, if you or someone else discovers this mistake immediately (i.e. pour about a quart of oil in your transmission with your old transmission fluid), there are some things that you can do. You can start the recovery process by following the steps below.

  • Remove the transmission oil pan from your vehicle
  • Let all of the oil and fluids in the transmission drain completely out
  • Replace the filter and then re-install the pan
  • Refill with the transmission with new transmission (preferably synthetic)

It is also important to note that this type of flush must be done asap to keep any unnecessary damage from being done to your transmission.

Can low oil cause transmission slip?

If you want your car’s transmission to last longer and work properly, you need to make sure that you check the fluids in your transmission regularly.

Every car manufacturer provides their own specific recommendations to their car owners, particularly when it comes to the timing of checking your transmission fluids.

Therefore, car owners are usually referred to their car manuals to find this information (i.e. based on a specific brand, year, and model of the car).

There are also some general suggestions and recommendations that are made by the automobile industry as a whole. For example, if you own a car with an automatic transmission, you may need to change your transmission fluid more often than manual transmissions.

The average recommended time for manual transmission vehicles normally ranges from 30,000 to 60,000 miles.

So, whatever the case or situation, it is very important that you adhere to the right information so that your transmission fluid is not too low or too dirty.

This is because transmission oil is essential to prevent your transmission from slipping due to one or more of the following problems.

  • Malfunction in the linkage or hydraulic system’s proper operation.
  • Problems with faulty sensors and faulty solenoids
  • Severe damages to the transmission
  • Worn out gears from the strain on the transmission trying to switch gears

That said, how do you check the transmission fluid level in your vehicle?

You may or may not know that today’s modern cars do not have a dipstick to check your transmission. Therefore, you will need the user’s manual to determine the course of action that you should take in these situations (i.e. professional service maintenance). On the other hand, if you have a car that has a dipstick, follow the simple procedures provided to you below.

  • After parking your vehicle on a leveled surface and waiting for the engine to cool off properly, you can pull out the dipstick.
  • Wipe off the dipstick with a paper towel.
  • Place the dipstick back into the transmission.
  • Remove the dipstick again, and then check the level of fluid in your transmission.

The fluid level indicator should be between the L and H marks. If it is too low, top the transmission fluid off with the appropriate amount of transmission fluid.


Can engine oil affect the transmission in your vehicle? The answer to this question is yes, especially if you do not discover this mistake immediately before severe damage is done.

Thankfully, there is a wealth of information online that explains what can happen to your transmission, particularly when it comes to severe damages that lead to the transmission slipping or either failing completely.

Also, because this is a mistake that anyone can make, two of the best courses of action are to learn how to avoid it (i.e. read the labels first), and how to recover if the engine oil is accidentally poured into your transmission.

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