Do you check transmission fluid with engine on or off

In today’s video, our friend Eric the Car Guy shows us the proper way to check automatic transmission fluid.

Should the engine be running or shut off? Should the fluid be hot or cold? What fluid level is optimum for transmission longevity and performance?

What do you do when there’s no dipstick, as is common on many new vehicles?

Per usual, Eric shares his expertise so that you can perform a new automotive task with confidence.

You may also want to read:

  • Transmission Fluid 101: Which ATF is Right for Your Vehicle?
  • Video: Intro to Valve Body Tech for Transmission Upgrades

Do you check transmission fluid with engine on or off
If you've ever popped the hood of your car, the first thing you may see is the engine. However, there are a myriad of fluids housed in this area, too. To keep your car running smoothly, check the transmission fluid from time to time before you set out on that next Ithaca, Trumansburg, or Watkins Glen adventure.

If transmission fluid levels are low, it can prevent the vehicle from operating safely in Syracuse and Baldwinsville. There are some steps that can be taken to check the fluid levels if your car has a dipstick.

Checking Transmission Fluid Levels

Do you check transmission fluid with engine on or off
If you're going to be checking the transmission fluid level at home, it's a good idea to warm up the car before you do so. If the car is checked while the engine is cold, it might give an inaccurate reading when you use the dipstick. After driving for about 10 minutes, park on an even surface and leave it running.

Shift through the gears and give the transmission the opportunity to spend a few seconds in each gear range. Then, put the car back into park and set the parking brake.

Open up the hood and locate the transmission dipstick. The owner's manual is a good place to look for instruction if you can't find it. Typically with a rear-wheel-drive car, the dipstick will be closer to the passenger side near the engine. Front-wheel-drive cars will have the dipstick on the driver's side, closer to the transmission.

Take the dipstick out, wipe it down with a clean rag or paper towel, then put it back into the transmission fill tube. Pull the dipstick back out of the tube, and check the fluid level against the markings near the end of the dipstick. Fluid can be added if necessary.

Every vehicle is different, which is something you'll want to keep in mind. Recently, some manufacturers have decided to remove the dipstick and replace it with a sealed-off unit, which requires electronic testing or a computer scan. If you don't want to check transmission fluid levels at home, or your car has one of these sealed units, our service team will be happy to do it for you.

Transmission Repair Service

Do you check transmission fluid with engine on or off
When adding transmission fluid at home, be sure to use what the manufacturer recommends. This can be found in the owner's manual. If the transmission needs more than a quart of fluid, or it seems like the fluid is being used frequently, our service team should inspect it to see if there may be a leak.

If a transmission is struggling, it may make a thud noise if the gears aren't shifting properly. If the car isn't accelerating or reaching highway speeds easily, that may also be a sign transmission repair is necessary. Learn more about our service offerings by reaching out to our maintenance team today.

Ensure Your Transmission Runs Smoothly

Transmission fluid acts as a lubricant for all of those important parts inside the transmission. When it comes to transmission fluid flushes and other transmission repairs, visit Maguire Dealerships near Ithaca, Trumansburg, and Watkins Glen.

It's our goal to ensure your transmission is running as it should in Syracuse and Baldwinsville. Contact us to schedule a service appointment today.

Q: When I check the transmission fluid level dipstick on my 2003 Honda Accord, do I check with the car on or off?

A:  This question isn’t as simple as you may think. Generally, any car with a dipstick for an automatic transmission is checked with the fluid at normal operating temperature and the engine running on a level surface.

According to the service manual for your Accord, it's a little different. The engine should be warm, but the fluid level is checked with the engine not running. So, in this case, warm up the engine, shift from park to reverse, then to drive and back to park, shut off the engine and then check the fluid level with the dipstick.

Q: I have a 2013 Mitsubishi Outlander Sport that I store in Florida for long periods of time. This can typically be two to three months. It is parked under a carport with no access to electricity for a trickle charger. The battery is two years old, but if the terminals are not disconnected the battery goes dead in about a month.

When I left in May, I decided to remove the negative terminal of the battery.  When I arrived in Florida recently, I connected the terminal and the car started right up.  However, every light possible comes on: ASC, engine light, 4-wheel-drive light, ABS light, etc. The car runs fine, other than the annoyance of these lights.

I brought the car to an Auto Zone store, and they used a scanner and said that the limited testing did not indicate anything wrong with the vehicle. They suggested bringing the car to a mechanic. I don't believe there is anything wrong. I would like to know how I can reset the system so the lights go away. How do I store the car in the future to avoid these lights?

A: You may have more than one thing going on. First off, you may have some sort of slight parasitic drain on the battery. A fully charged battery in good condition should be able to hold a charge for a month or even a little longer. I would start with checking all of the fuses and fully recharging the battery and retesting it.

I would also completely “reboot” the car's computer systems. This is accomplished by disconnecting the positive and negative cables and connecting the cables together with a jumper wire. If you are unsure about this, have your repair shop do it for you. This will completely discharge the capacitors in the system and clear all of the memory.

You may find after you reboot the system that it acts a little odd for a couple of restarts until it relearns the proper operation.

Even though you don’t have electricity where you park, you do have the power of the sun to maintain the car’s battery. You could look at solar charger maintainers. CTEK makes a true battery maintainer with an add-on solar panel. Less expensive battery chargers are available from Schumacher and from Deltran, which makes the very popular Battery Tender. Both have solar battery maintainer/chargers.

Q: I have driven Nissan products for approximately 35 years and find them to be fairly reliable, for the most part. My mechanic has nothing good to say about them for reasons unknown. What is your opinion of the newer Nissan models such as Rogue, Altima and Sentra, and just Nissan in general?

A: Some work out fine, but the CVTs (continually variable transmissions) are either perfect or fail around 75,000 miles. Some earlier cars had some severe rust issues as well.

I do believe that all of the changes in management have helped with quality over what I have experienced in the past.

The latest Roque is pretty good, as is the Altima. The last Sentra I evaluated was just a terrible car, and the Murano is just not my cup of tea.

Problems with some Nissan models are generally traced to electrical issues.

My last evaluation of the newest Frontier truck was quite good, and the extended-range Leaf EV was practical and fun to drive. 

As a whole, I would put Nissan quality at mid-pack, with the more popular Altima, Maxima and Roque in the top one third when compared with other models.

Q: Every time I take my Toyota in for service, I expect the fuel filter to be replaced, along with routine maintenance. When I have asked why they didn’t replace the fuel filter, they just said it didn’t need it.

I have a lawn tractor and a small boat, and I replace those filters every three years. Why not the car’s filter?

A: Some filters are designed to last the life of the car and are only replaced if the fuel was contaminated. Many Toyota products have large fuel filters which, under normal conditions, don’t require replacement.

Do you check transmission fluid with engine on or off

John Paul is the AAA Northeast Car Doctor. He has more than 40 years of experience in the automobile industry and is an ASE-Certified Master Technician. Write to John Paul, The Car Doctor, at 110 Royal Little Drive, Providence, RI 02904. Or email and put “Car Doctor” in the subject field. Follow him on Twitter @johnfpaul or on Facebook.

Should my engine be running when I check my transmission fluid?

Transmission fluid expands in heat and in order to receive accurate results, it must be under normal operating conditions. If the fluid is checked when the engine is cold, you may get false results indicating the fluid is low. Allow the engine to continue running while you check the level.

What is the proper way to check transmission fluid?

Take the dipstick out, wipe it down with a clean rag or paper towel, then put it back into the transmission fill tube. Pull the dipstick back out of the tube, and check the fluid level against the markings near the end of the dipstick. Fluid can be added if necessary.