Should Your Car Be Running When Checking Transmission Fluid?

Introduction

Checking your transmission fluid is an important part of regular car maintenance. But should your car be running when you check the fluid? The answer is: it depends.

Manual Transmissions

For manual transmissions, it is not necessary to have the car running when checking the fluid. The fluid level can be checked with the engine off.

Automatic Transmissions

For automatic transmissions, the answer is a bit more complicated. On most automatic transmissions, it is best to check the fluid with the engine running and the transmission in park. This will allow the fluid to circulate and give you an accurate reading.

Exceptions

There are a few exceptions to the general rule. Some automatic transmissions, such as those found in some Honda and Acura vehicles, require the engine to be running and the transmission in neutral when checking the fluid. Refer to your vehicle’s owner’s manual for the specific instructions.

Why Does It Matter?

Checking the transmission fluid with the engine running or not running can affect the fluid level reading. When the engine is running, the fluid is circulating and the level will be higher than when the engine is off. If you check the fluid with the engine off, you may get a false low reading.

Conclusion

To ensure an accurate transmission fluid reading, follow the instructions in your vehicle’s owner’s manual. In general, it is best to check the fluid with the engine running and the transmission in park. However, there are some exceptions, so be sure to consult your owner’s manual for the specific instructions for your vehicle.