Say you are driving from Colorado to Utah, and your engine starts to overheat or produce a clunking noise.
What’s the first thing you’ll check after pulling over your car?
Well, checking the engine oil level should be near the top of your list. An engine with low or no engine oil often produces this clunking noise.
And let’s say the engine oil is below the minimum mark on the dipstick. Should you add engine oil right then and there when the engine is hot? Or should you wait a bit?
The short answer is: Yes. You can add engine oil to a hot engine.
But that doesn’t mean it’s the ideal way. Many things can go wrong when dealing with a hot engine or oil.
Read on to find out what happens when you add engine oil to a hot engine and what you can do to improve your vehicle’s health and life:
What Happens if You Put Oil in a Hot Engine?
Probably nothing!
But there are risks of:
Splash
A splashback can occur when cold oil touches the hot engine surface. This splash can burn your skin.
Overfilling or Underfilling
The hot oil is thin. In other words, your dipstick may show a higher reading than the actual reading.
As a result, you might overfill or underfill the engine. Castrol recommends waiting 20 minutes for the engine to cool down before adding any engine oil.
Castrol recommends waiting 20 minutes for the engine to cool down before adding any engine oil.
What Can Go Wrong if You Change the Oil While the Engine Is Still Hot?
You should change the oil when the engine is neither extremely hot nor cold. But what can go wrong if you start changing the oil while the engine is still hot?
Poor Oil Drainage
While you’re driving a car, an oil pump moves the engine oil around engine components in a specific pathway — also called an oil circuit — to absorb the heat from your engine. When the car is switched off, the oil pump turns off, and the oil slowly returns to an oil container, or oil sump.
Almost 95% of the engine oil flows back to the sump within 2 minutes of turning off the engine. The remaining 5% oil returns slowly over the next 5-10 mins.
This remaining degraded oil might cause problems for your engine later on if you add engine oil without removing it. Put simply, it’s better to let the engine cool down and the engine oil to collect in the oil sump if you’re not in a total hurry.
Oil Burns
The oil in a hot running engine can reach a temperature up to 200 Fahrenheit. It can fall on your skin as you open the oil drain plug, leading to oil burns.
How Often Should You Change Engine Oil?
For most vehicles, the oil change interval is specified in the owner’s manual.
In general, Ford Motor Company recommends changing the oil every 7,500 miles or six months, whichever comes first.
But if you use the latest synthetic oil, you can even wait 20,000 miles or a year before changing your engine oil.
How Often Should You Check Engine Oil Levels in Your Car?
Most carmakers recommend checking engine oil levels at least once a month or every time you fill up the gas tank.
Many modern cars also have low-oil-level sensors that trigger a warning light on the dashboard if the oil level gets too low.
How To Achieve the Ideal Temperature for Changing Engine Oil?
The engine should neither be hot nor cold. Instead, it should be warm.
You can reach this warm temperature by following these steps:
- Start the engine and keep it running for 5-10 mins.
- Turn the engine off and let it sit for about 6-7 minutes.
- Drain out the engine oil
Why Should You Change the Engine Oil Regularly?
Changing engine oil on time carries a lot of benefits for your car engine in the long run. It is necessary for:
- Good performance of your engine
- Lubrication of the moving parts
- Reduction of friction
- Keeping engine temperature under check
Final Thoughts: Can You Add Oil to a Hot Engine
Yes. You can add oil to a hot engine without damaging your car.
Still, waiting for 5-10 minutes to let the engine cool down ensures personal safety and proper drainage. For more engine oil-related information, explore our blog.
