How to check transmission fluid in Acura RSX?

In the Acura RSX, checking transmission fluid depends on the gearbox in your car. If you have an automatic, you’ll use the dipstick and check the level when the fluid is warm. If you have a manual, there is no dipstick—the level is checked via the fill plug on the transmission housing and topped off with gear oil. This guide walks you through both cases so you can verify levels and top up safely.

Automatic transmission

The following steps apply to RSX models with an automatic transmission. Use the recommended ATF (Honda/Acura DW-1 or the specification listed in your owner’s manual) and avoid mixing fluids. Check the level when the transmission is at normal operating temperature and the vehicle is on level ground.

1. Warm up the car so the transmission reaches its normal operating temperature, either by driving a few miles or letting it idle until hot.


2. Park on level ground and engage the parking brake; keep the engine running.


3. Locate the transmission dipstick, pull it out, and wipe it clean with a rag.


4. Reinsert the dipstick fully, then pull it out again to read the level. The fluid should show on the “Hot” range when the transmission is warm.


5. If the level is below the proper mark, add ATF slowly through the dipstick tube using a clean funnel; add small amounts and recheck frequently to avoid overfilling.


6. After topping off, reinsert the dipstick, wipe away any spills, and run the car through the gears for a brief moment if advised by your manual, then recheck the level on level ground.


7. Dispose of any spilled fluid properly and confirm there are no leaks around the dipstick tube or transmission.

Conclusion: For automatic RSX models, keep the transmission fluid within the manufacturer’s marks on the dipstick when the fluid is warm, and use the recommended ATF DW-1 or its specified equivalent.

Manual transmission

For RSX models with a manual transmission, there is no dipstick. The fluid level is checked via the fill plug on the side of the transmission housing. Use the correct gear oil (typically GL-4 75W-90) as specified in your owner’s manual, and avoid mixing fluids.

1. Park the car on level ground with the engine off and the parking brake engaged.


2. Locate the transmission fill plug on the side of the transmission. If needed, safely raise the car to access the plug.


3. Remove the fill plug with the appropriate tool; the fluid should be at or near the bottom edge of the fill hole.


4. If the fluid is well below the hole, add the correct gear oil gradually through the fill opening until it begins to seep out or reaches the bottom of the hole.


5. Reinstall the fill plug and torque it to the manufacturer’s specification; wipe away any spills.


6. Check for leaks around the plug and ensure a clean fill area.

Conclusion: For manual RSX transmissions, fill until the level is at the bottom edge of the fill hole (or until slight seepage is observed) with GL-4 75W-90 gear oil, and always refer to the owner’s manual for exact specifications and capacities.

Summary

The RSX requires different fluid-check methods depending on the transmission. Automatics use a dipstick and should be checked when warm on level ground, topping up with Honda ATF DW-1 as needed. Manuals have no dipstick; check and top off via the side fill plug using GL-4 75W-90 gear oil until the level reaches the fill hole. Always consult the owner’s manual for exact specs and service intervals, and handle all fluids with care to avoid contamination or burns.

Do I check my transmission fluid while the engine is running?

Yes, for automatic transmissions, you should check the transmission fluid with the car running. It's crucial to let the engine warm up first, then shift through all the gears while keeping the brake pressed, and finally check the fluid level while the engine is in park or neutral. Checking while the engine is on ensures the fluid is circulating properly and the torque converter is full, giving a more accurate reading. 
This video demonstrates the importance of checking transmission fluid while the engine is running: 59sOBD InsightsYouTube · Sep 3, 2024
Why check with the engine running

• Accurate reading: The fluid circulates through the transmission, including the torque converter, while the engine is running. This prevents a false high reading that can occur if the fluid has drained back into the pan when the engine is off. 
• Hot fluid: Checking the fluid when the engine is warm gives the most accurate reading because transmission fluid expands as it heats up. Your dipstick often has separate "hot" and "cold" markings. 
• Functionality: The engine needs to be running to activate the transmission and its internal parts, which is necessary for a proper check. 

How to check automatic transmission fluid

1. Make sure the car is on a level surface and set the parking brake. 
2. Start the engine and let it run until it reaches normal operating temperature. 
3. Press the brake pedal and slowly shift the gear selector through all the gears (P, R, N, D, etc.), pausing for a few seconds in each. 
4. Return the gear selector to the park (P) position. 
5. Locate the transmission fluid dipstick, pull it out, and wipe it clean with a rag. 
6. Re-insert the dipstick completely, then pull it out again to check the fluid level against the "hot" marks. 

You can watch this video for a step-by-step guide on checking transmission fluid: 52sJiffy LubeYouTube · Jun 29, 2015
Important considerations

• Consult your owner's manual: The specific procedure can vary between vehicles. Some modern vehicles may not have a dipstick, or some may have different checking procedures. 
• Manual transmissions: The procedure for checking manual transmission fluid is different and typically requires the engine to be off and the vehicle to be on a lift. 
• Safety: Be careful when working around a running engine. Some sources recommend using wheel chocks for added safety. 

How to check Acura transmission fluid?

How to Check Your Transmission Fluid

1. Let your engine run for 10 minutes before proceeding, the engine must be warm to get an accurate reading.
2. Find the transmission fluid dipstick.
3. Remove the dipstick and touch the fluid.
4. Use a rag to wipe off the dipstick.
5. Use a funnel to bring the fluid level up to the proper level.

Why is there no transmission dipstick?

There is no transmission dipstick in many modern vehicles because transmissions are now "sealed," which prevents contamination and is designed to last for the life of the vehicle. This is also due to advances in technology, which use electronic sensors for more accurate monitoring and require specific procedures for checking the fluid that a simple dipstick cannot handle. Additionally, some sealed transmissions require specialized tools and knowledge to check, which discourages owners from doing it themselves and may lead to more frequent shop visits. 
This video explains why manufacturers are eliminating transmission dipsticks: 58sJust Call Me EddieYouTube · Feb 12, 2025
Reasons for the absence of a transmission dipstick 

• Sealed transmissions: Many modern transmissions are sealed, meaning they do not lose fluid and therefore do not require regular checking by the owner. They are designed with a much higher level of efficiency and better tolerances than older models. 
• Prevention of contamination and misuse: Sealed transmissions prevent dirt, water, and other contaminants from entering the system, which can cause damage. Removing the dipstick also prevents owners from accidentally using the wrong type of transmission fluid, which could be catastrophic, especially for complex CVTs or dual-clutch systems. 
• Advanced fluid monitoring: Some modern vehicles use electronic sensors to monitor fluid levels and quality, sending this information directly to the car's dashboard. These systems are more accurate than a traditional dipstick and reduce the risk of human error. 
• Complex checking procedure: Checking the fluid in a sealed transmission often requires specific temperature conditions and a special process involving a mechanic lifting the vehicle and removing an inspection plug. A traditional dipstick is not designed to be used with this type of system. 

What to do if you don't have a dipstick

• Consult your owner's manual to determine if your vehicle has a sealed transmission and what the recommended service interval is. 
• If you suspect a leak or need to check your transmission fluid, refer to your vehicle's manual for the correct procedure or consult a dealership or qualified mechanic. 

How do I check my transmission fluid if there's no dipstick?

To check transmission fluid without a dipstick, use the vehicle's transmission fill and check plugs, which are typically on the side and top of the transmission case, respectively. This procedure requires the engine to be running and at operating temperature, and the vehicle to be on a level surface. The fluid level is correct when it begins to trickle out of the inspection plug, or a specialized dipstick can be inserted into the fill plug to measure the level.
 
This video demonstrates how to check transmission fluid level on a vehicle with no dipstick: 53sEricTheCarGuyYouTube · Jan 11, 2019
Using the transmission fill and check plugs 

1. Warm up the vehicle: Drive the car to bring the transmission to its normal operating temperature. 
2. Park on a level surface: Ensure the vehicle is parked on a flat, level surface for an accurate reading. 
3. Locate the plugs: Find the transmission fill plug (usually on top) and the check or inspection plug (on the side of the transmission case). Consult your vehicle's repair manual for the exact locations. 
4. Check the level:
   • With the engine running, slowly loosen and remove the check plug. 
   • If fluid flows out, it indicates the level is correct, so let it flow until it becomes a trickle, and then replace the plug. 
   • If no fluid comes out, the level is low. Add fluid through the fill plug until it starts to flow out of the check plug. 
5. Add fluid (if needed): If the level is low, add the correct type of transmission fluid through the fill plug using a pump until it just begins to trickle from the check plug. 
6. Tighten the plugs: Reinstall both the check and fill plugs securely. 
7. Check for signs of damage: While checking, note the fluid's color and smell. If it looks dark, brown, or has a burnt smell, it may be time for a service. 

Alternative method: Use a specialized dipstick 

1. Purchase a universal dipstick: Buy a flexible, compatible dipstick designed for vehicles without a standard transmission dipstick. 
2. Locate the fill plug: Find the fill plug on the transmission. 
3. Check the level: With the engine running and at operating temperature, remove the fill plug and insert the specialized dipstick until it reaches the bottom of the pan. 
4. Read the fluid level: Pull the dipstick out and check the fluid level against the markings. 
5. Add fluid: If the level is low, add fluid through the fill plug and recheck until the correct level is reached.