Can You Add Oil To a Hot Engine?

We answer all your questions about checking your engine oil, topping off your oil, and everything you need to know to properly care for your car

Maintaining the level of your engine’s oil can frequently be vital to the vehicle functioning efficiently for a long time. You will sometimes receive a notification from your dashboard to check for oil. It simply signifies that your car oil levels are incorrect, no matter the message it is important to check all your fluids but most importantly your oil on a regular basis.

By Maurice Rodriguez
August 4, 2022

The proper care and maintenance of your vehicle’s oil is one of the best maintenance habits a driver can routinely check to ensure a long engine life. A monthly check of the oil when you are filling up at the gas station can save costly repairs and maintenance on your vehicle.

In this blog, we will discuss the most common driver questions about when to check your oil, how to check it, and what to know when checking the fluids. We have created a visual guide on how to check your oil and a quick guide on how to tell the difference between Good vs Bad Oil.

Yes, there is no harm in putting oil in the engine when the engine has been running for long periods.

Making sure your engine always has the proper level, and type of oil is always a good reminder when caring for your vehicle and prolonging the life of the engine.

If the air temperature is above 100°, you may be wise to wait, not because you will damage the engine, but because you may burn yourself if you touch the engine block.

Signs You Need an Oil Change or to Add Oil

1.  Dark or Dirty Oil

Dark, dirty, or sludgy oil is the first sign that you are in need of an oil change. If your car’s oil is dark and not very clear then your oil has begun to break down and the detergents in your oil have been saturated with soot and carbon deposits.

The easiest way to know if you need to change or add oil is to get a rag and check the old dipstick. A quick check can let you know the state of your car’s oil.

2.  Engine noise

The main purpose of engine oil is to lubricate internal engine parts, reduce friction, and keep the engine from seizing. When your engine oil becomes dirty over time it loses its ability to effectively lubricate your engine at higher temperatures and engine parts begin to wear prematurely.

This failure to lubricate will cause your engine to make excessive noise.

The dreaded check oil light

3.  Check Engine or Oil light

While the check engine or oil light are great reminders to give your car’s engine some attention, it is wise to rely on these lights to stay on top off your engine’s oil level.

Regular oil level checks should be done between oil changes to ensure the level remains topped off.

4.  Burning Oil Smell in Cabin

If you smell burning oil in your cabin, this may be an indication of an oil leak or oil burning in your engine compartment.

This is a good indicator that a thorough inspection of the engine bay and under the car to locate the source of the leak or issue.

5.  Overheating

Engine oil not only helps lubricate it also reduces friction which in turn dissipates excessive heat and wear on engine parts. So, it stands to reason that if your car’s engine is low on oil, your engine will begin to produce excessive heat and begin to overheat.

If your car is overheating and you believe it is from a lack of oil be cautious when checking the oil as you may burn yourself. Allow the engine to cool with the hood open for at least 15 minutes before inspecting the oil.

How Often Should You Top Up Engine Oil?

That depends. Is your engine leaking oil? Checking your oil regularly between oil changes is always a good habit to maintain. Excessive oil usage can be a sign that your car has a leak, or burning oil, which is a more serious problem.

Topping off your oil when your car needs oil is always highly recommended but, should not take the place of regular oil changes.

Wondering how long to wait? Read on.

How long does it take to cool the engine before adding oil?

That all depends on how long the engine was running before it was shut off and the air temperature. But, in general, once an engine has been turned off it should be safe to add oil after 10 to 30 minutes depending on the outside temperatures.

Is it better to add oil to a hot or cold engine?

It is always better to add oil to an engine when it’s cold as you will get a better reading from the dipstick. When an engine is running the oil is being distributed by the oil pump. It takes about 10 minutes for the oil to settle back into the oil pan and take an accurate reading again.

How to add oil and check oil levels?

Detailed instructions on how to check your oil

Checking your engine’s oil is an easy and important step in the care of your car’s engine. All drivers should be well versed in how to check the oil and understand the levels and right color and consistency to look for when checking the oil. We have laid out a couple of items your will need and a couple of steps to check your oil.


Simpli-Magic Shop Towels
Scott Blue Shop Towels in a Box
Disposable Black Nitrile Gloves 6 Mil
Gorilla Grip Slip Resistant All Purpose Work Gloves
Hopkins FloTool 
 Lubricant Funnel with Flexible Extension
  • Oil – See your owner’s manual for recommended grade
Castrol GTX High Mileage
Valvoline High Mileage


  1. Park your car on a level surface to you can take an accurate reading
  2. Turn off your car
  3. Put on the gloves of your choice
  4. Open your hood
  5. Locate the dipstick
  6. Remove your dipstick
  7. Remove any oil on the dipstick with your shop towel
  8. Re-insert your dipstick and take your actual reading
  9. You want to check the level and color, and inspect the oil for coolant or metal debris. If you find coolant or debris, schedule an appointment with your mechanic for a more thorough inspection.
  10. If your levels are low, add one quart at a time and recheck to levels until you reach the MAX level. Make sure you are using the manufactures recommended oil for your car. See your owner’s manual for specifics.
  11. Once you have reached the necessary level, re-insert your dipstick, and don’t forget to put the oil cap back on. I’ve had this happen. Not only does it make a mess your car won’t run correctly.


How much oil is too much on the dipstick?

When checking your fluid it can be easy to overfill your car with too much oil. In general, going over by a half quart won’t have any adverse effects on your engine. Wait for the engine to cool after 15 minutes and recheck to see if the level has settled. If you see foam on the dipstick, consider draining the oil.

If too much oil was added then you will have to get a drain pan and drain some oil or take your car to an oil service station.

What happens if too much oil is added?

If too much oil is added to your vehicle your car’s crankshaft will agitate the oil in the oil pan and create foam. This creates a situation where excessive pressure is being put on internal components, gaskets, and seals.

Can I open the engine oil cap when hot?

Yes, but a 10-minute cooling-off period is recommended.

Checking the oil is more accurate when the oil has settled and is all in the oil pan. Then, using gloves and a shop towel the oil cap can be removed and levels can be checked.

Should I let my car cool down before adding oil?

A cooling-off period is not necessary but does allow for the oil to settle in the oil pan and allows you to take a more accurate reading from your dipstick. Also, be cautious you don’t burn yourself on the engine. A set of mechanic gloves will help keep your hands clean and more importantly from burning.

Can you add oil without changing it?

Checking your oil is always part of a good vehicle maintenance routine. If you check your oil and find that is low, fill it back to the max level and inspect the oil for color and consistency. If the oil is black and sludgy, you may want to consider changing the oil or taking it to your local oil service station.

If your existing oil looks clean and amber-colored like the picture below you can add oil and not worry. Periodically, check your oil levels every month to ensure you aren’t burning oil or have a leak.


The proper care and maintenance of your vehicle’s oil levels will ensure you will always have a stress-free motoring experience. You will have the confidence that you are taking proper care of your car or truck and your engine life will be a long and happy adventure.

We are all things cars.

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