Best Car Fluids Top-up Tips (+7 Maintenance Tips)

In this brief article we are going to discuss Troubleshooting tips on topping-up and maintaining your vehicle’s Fluids..

Should my car be running when I add coolant?

No, it is not recommended to add coolant when your engine is running. Therefore, first make sure that:

  • Your car engine is turned off and cooled for at least 20 minutes
  • Your car is in either Park or Neutral, and that you have engaged the parking brake
  • Now open the hood and locate the engine coolant reservoir. It should be translucent white color and plastic, with a hose that connects it to the radiator.( Do not fill coolant directly into the radiator cap)
  • The reservoir will have markings with a fill range on the side. Once the engine has cooled, the coolant level should be up to the cold fill line. (You can also keep in mind that in the worst case, your coolant reservoir tank should be at least 30% full) 
  • Now, you can loosen the reservoir cap just a little, and allow the pressure to release. Subsequently, the cap can be removed completely.
  • If you find that the coolant level is below the cold-fill line, add the correct coolant to the reservoir. You can either use the diluted coolant by itself (if available), or a mixture of equal parts of coolant concentrate along with distilled water.
  • When the coolant is topped-up till the cold fill line, replace the cap and tighten it properly until you feel a click.

How much coolant does my car need when empty?

Most car cooling systems have a capacity of around 5 liters. Engine coolants are usually available in containers of between 1 – 20 liters. You can choose the quantity according to your car’s capacity and purchase the exact amount that you require.

Why is my Car still overheating but it has coolant in it?

If the coolant in your car isn’t circulating freely through your engine, it will lead to overheating. Even if there happens to be no leaks, gradually, coolant could get clogged with particles like rust disrupting the coolant circulation.

One easily overlooked, but easily rectifiable probable cause could be a faulty radiator cap. The radiator cap acts as a pressure release valve that lets coolant flow in or out of the radiator and reservoir. If, for some reason, the radiator cap spring fails to function at its intended pressure, then coolant might be trapped in the reservoir, with the radiator overheating due to it not receiving coolant.

Other probable causes could be a faulty radiator fan, broken water pump, or clogged coolant hose.

How long should I wait to start my car after adding coolant?

No need to wait, you can start the car immediately.

But, if you have drained coolant and refilled your cooling system, you MUST start the engine immediately.

If you don’t start the engine, the gasses (air) that got into the system during refilling of the fully drained system, will expand at a faster rate than the liquid coolant present when the engine becomes hot. 

This pressure resulting from the expansion of trapped gasses can potentially blow out coolant hoses or even weak radiators. Running the engine helps to get any air bubbles out of the system. But make sure to keep the radiator cap open when initially running cold; this will allow the trapped air to escape.

Should my car be running when I check the Engine oil?

No, ideally, the engine should be turned off. It is recommended to check the oil level at fully cold condition, i.e, either before turning on the engine or at least 5 to 10 minutes after turning off the engine. The reason is that you must allow all the oil to settle in the oil pan so that the dipstick can get an accurate measurement.

Should my car be running when I add transmission fluid?

Yes, your car’s engine should be running at the time of adding  transmission fluid. But do this only after you ensure that you have the transmission in park and the handbrake ON for safety. Always refer to your car’s owner’s manual for buying the correct transmission fluid for your car.

Should my car be running when I check the transmission fluid?

No, it is not needed and it would be unsafe to keep the engine running while you check the transmission fluid. The requirement is that you check your transmission fluid level when the engine is warm, like 5 minutes of running. Then switch off and check the transmission oil dipstick after cleaning once and dipping again.

There should typically be two marks on the dipstick marked as “Cold” and “Hot”. 

Sometimes there may be only dots, notches, or lines next to each label to provide the recommended fluid level range. Since the engine is barely warm after running for only 5 minutes, you should check only the “Cold” or bottom range.

If the engine was already hot, meaning you drove normally fr say 10 miles, and then checked the oil level, you should check for the markings on the dipstick that indicate “Hot” range.


In this brief article we have discussed Troubleshooting tips on topping-up and maintaining your vehicle’s Fluids.

Please feel free to ask in case of any questions or comments.

Frequently Asked Questions (FAQs): 


Should my car AC be dripping water?

If your car’s AC drips water, in most cases, this should be normal. Particularly on hot days when the A/C is set to run at full blast water would drip. Car AC systems are designed so as to allow collected water from the evaporator to drain out from the bottom.

The system cools the cabin by removing humidity from the air. The AC system’s evaporator core condenses all this humidity (and turns it into water). The condensed water is allowed to exit the car onto the road surface via the evaporator drain.


Should my car be leaking water?

If your car AC is working full blast, then it would be normal for water to drip because of the condensation of humid air. But if you find that there is water leaking even when the AC is not working then it could be one of two scenarios:

  • Water dripping from the tailpipe due to exhaust condensation. This would be clearly visible looking at the tailpipe
  • A leaking radiator hose or hose connector. While it is not visible from outside the vehicle, you can observe underneath the car as to where the drips come from. If it happens to be very close to the front end of the car, then the source might most probably be the car’s engine cooling system.

While exhaust condensation is normal, a leaky radiator hose is something you should really be concerned about and attend to at the earliest as it might lead to engine overheating.