Do You Check Transmission Fluid While the Car Is Running?

Transportation is one of the most important activities among the busy lives of millions of people of different occupations and ages. Some of us prefer to use public transport, whereas others prefer to choose private transport.

Both have their own pros and cons but owning a private transport such as a car also comes with the responsibility of diagnosing it – which you can learn about in the extract below.

Do you check transmission fluid while the car is running?

You should check the transmission fluid of a car while it is running to receive accurate results. While the engine is on, the transmission fluid expands due to heat and gives the correct level reading. If the engine is cold, the reading might show a low level of fluid when it is not.

The transmission of a car is an important part of the car and is responsible for the optimal performance of the car. Maintaining a good transmission fluid level just like other components of the car is vital in order to have your car running at a good speed.

Regularly checking the level, color and the scent of the transmission fluid can help you keep the car under good maintenance.

Checking the transmission fluid is simple, it has a fluid dipstick similar to the oil dipstick which is dipped into the transmission fluid with readings marked onto the stick.

The transmission fluid dipstick is used to measure the level of transmission fluid present in the car. It is an effective way of checking whether the fluid level is low which could be due to any leaks in the vehicle.

You need to make sure that the level of transmission fluid is not low or too high due to overfilling the reservoir. Transmission fluids are necessary lubrication fluids which are responsible for maintaining the vehicle’s optimal operation and its performance.

The transmission fluid in a vehicle lubricates its moving parts, prevents oxidation as well as prevents rust.

Checking the transmission fluid of a car requires you to park your car and then let the engine run for a couple of minutes.

This allows the transmission fluid to heat up and expand in order to get accurate results and measurements because the fluid is in its active working state.

But If the fluid level is measured when the engine is running cold, the fluid would be in a compact state thus giving a misleading reading that the fluid level is low.

However, some manufacturers such as Honda recommend its users to turn off the car engine before checking the transmission fluid level.

Should you check the transmission fluid while the car is running?

The transmission fluid of a vehicle plays an important role in maintaining the performance and operation of the engine.

It not only provides lubrication but also reinforces the durability of the moving parts by preventing oxidation and rusting by coating the surface of the parts.

Which is why it is essential that you make sure the transmission fluid level of your vehicle is not running low.

Checking the transmission fluid level is easy and does not require the help of a professional, but there are some conditions to follow to ensure the accurate measurement of the fluid level.

You need to measure the transmission fluid level when it is in its active state – which is when the car engine is running and hot.

The heat from the engine warms the fluid and causes it to expand, therefore giving an accurate reading. But if the engine was cold, the fluid may incorrectly show lower reading in the dipstick.

Why do you check transmission fluid with the car running?

Transmission fluid level is an important component of a car since the fluid not only optimizes the engine performance by lubricating its moving parts but also prevents oxidation and rusting.

Which is why it is necessary to check the transmission fluid when the car engine is running because of the following reasons:

Transmission fluid is in its active state when engine is running:

To measure the correct level of the transmission fluid, you need to make sure that it is in the same state as it would be when the car is running.

To bring the transmission fluid to that state, you need to start your car and let the engine run for several minutes to get the engine heated up.

While the engine is running, the fluid heats up as well causing it to expand and reach a viscosity that it is intended to function as, which is why measuring the transmission fluid with the engine running provides the most accurate reading.

To prevent misreading from the fluid dipstick:

If the transmission fluid is running low, then it can be problematic since the moving parts will not be functioning optimally and on the other hand, if the transmission fluid level is very high then there will be overflow and over lubrication of the parts causing a mess.

If the fluid level is measured when the engine is cold, the dipstick will show a lower reading than the actual fluid level. This might prompt you to pour transmission fluid, causing the level to overfill and end up being overloaded.

What fluid do you check while the car is running? Can you check transmission fluid without the car running?

There are different important fluids that flow within the car engine that is responsible for the optimal performance and durability of a car such as an Engine Oil, Transmission Fluid, Coolant, and Brake Fluid.

Each of these fluids has a distinct diagnostic method however, among these fluids, Transmission Fluid requires your car engine to be running.

Almost all vehicle manufacturers instruct you to check the level of transmission fluid of the vehicle after turning the car on for a while.

They manufactured the vehicles in such a way that the transmission fluid dipstick gives accurate reading when the engine is running and hot.

However, vehicle manufacturers like Honda have completely contrasting instructions regarding this matter.

Honda instructs its users to keep the vehicle parked and the engine to be cold before checking for the transmission fluid level, so you surely can check the transmission fluid with running the car.

How to accurately check your transmission fluid while running a car?

The steps for accurately checking the level of transmission fluid in your car is explained in detail below:

Start your car and let the engine heat up:

Before you proceed to measure the transmission fluid level, you need to make sure your car is parked on a level surface. After that, lift the hood of your car and turn on your car and let the engine run for a couple of minutes to let it warm up.

It is necessary for the engine to warm up to ensure that the transmission fluid has reached its normal operating temperature and has expanded.

Note that if your car is manufactured by Honda, then you should ignore this step completely. Honda vehicles do not need its engine to heat up before measuring the transmission fluid level.

Find the transmission fluid dipstick:

Once your car engine has been heated up considerably, you should look for the transmission fluid dipstick which has a hook-like structure sticking out.

The stick often comes with labels for easy access and can be noticed to b red, pink, or yellow in color. The fluid dipstick is usually located around the oil dipstick for front-wheel drive vehicles and behind the engine for rear-wheel-drive vehicles.

Measure the level of the transmission fluid from the dipstick:

After you have located the dipstick, pull it out and use a clean tissue or rag to wipe it clean and make sure no fluid residue is sticking to the dipstick. Now locate the labels on the dipstick that reads “full” and “low”.

Dip the stick back into the reservoir take it out again and check where the fluid has made a mark.

When to check transmission fluid?

Maintaining an optimal level of transmission fluid is necessary in order to keep your vehicle’s engines and moving parts functioning efficiently.

Unless you notice visible problems such as leakages of the fluid reservoir, most auto manufacturers would recommend you to manually check the fluid level once every 40,000 miles.

Should transmission fluid be hot or cold?

Most vehicle manufacturers design the transmission fluid reservoir in such a way that requires the fluid to be hot in order to give an accurate reading on the dipstick.

However, manufacturers like Honda designed their fluid reservoir to give an accurate readings on cold temperatures of the transmission fluid.

Final Thoughts

To get accurate results, test a car’s transmission fluid while the engine is running. The transmission fluid expands due to heat and provides the accurate level measurement but if the engine is cold, the reading may indicate that there is a low level of fluid when there isn’t.