Why is White / Blue Smoke Coming from the Engine?

Is your engine running, but emitting white or blue smoke? Find out what could be causing white smoke from the engine and how to go about fixing the issue.

What could be causing the white/blue smoke from my engine?
How to troubleshoot engine smoking

WARNINGAlways read the engine and equipment manual(s) before starting,operating, or servicing your engine or equipment to avoid personal injury or property damage. See an authorized dealer or contact Briggs & Stratton if you are unsure of any procedure or have additional questions. Find all Engine Safety Warnings


What could be causing the white/blue smoke from the engine?

white/blue smoke from engine

Blue or white smoke coming from your engine usually indicates burning oil, which can be caused by:

  • Overfilling the crankcase with oil
    Incorrect oil grades
  • Operating engine at greater than a 15 degree angle
  • Inoperative crankcase breather
  • Crankcase air leak
  • Blown head gasket
  • Worn cylinder and/or rings
  • Turning/tilting the engine on its side for storage, oil change or any other reason.

Note: If the engine has to be tilted, ensure the spark plug is facing upwards to help prevent oil from escaping the crankcase.

Other reasons for blue or white smoke from engines include going over the engine’s oil capacity, an obstruction in the breather tube (located behind the air filter), damages to the cylinder/piston rings, and more.

Engine oil capacity is dependent on your specific engine model and can be determined by checking the Oil Recommendation FAQ. You can also learn how to check the oil level and change intervals to ensure the engine is running at the correct oil capacity.

How to Troubleshoot Engine Smoking

If you wish to troubleshoot and repair the small engine yourself,

  • Step 1: Are you tilting the engine or using it at more than a 15 degree angle? Tilting your mower or equipment can cause leaks. Right the machine before moving forward.
  • Step 2: Checking and changing the oil is an easy troubleshooting technique for this problem. Check to see if the oil is overflowing or you’re using the wrong grade/type.
  • Step 3: Check the crankcase for leaks.
  • Step 4: Is the head gasket blown?
  • Step 5: Are the rings and/or cylinder worn?

Once you’ve determined the issue, you can find specific small engine repair instructions in the Briggs & Stratton Repair Manual, which is available purchase through our website.

Note: You can find and order the specific engine repair manual by specific engine models. You can also buy the repair manual locally from a Briggs & Stratton Dealer.