Q: Mixing engine oil causes light knocking in the engine. Should the oil be changed immediately?

asked by on

mixing engine oil accidentally(10w-30 and 10w-40) causes light engine knocking. It started about 3 weeks ago, should I change oil immediately ?

My car has 66000 miles.
My car has an automatic transmission.

If you are using too thick of an oil, the engine may not be properly lubricated. The oil should be changed as soon as possible. If the engine was previously low on oil, topped off with additional oil, and noise persists, the engine’s internal bearings may have been damaged. Have the oil and filter changed, put in the correct oil, and see if noise continues. If it does, a YourMechanic professional can help you check the engine for bearing damage.

Was this answer helpful?

Need advice from certified mechanic? Get help now!

Over 1,000 mechanics are ready to answer your question.
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details

Ask a Mechanic
(100% Free)

Have a car question? Get free advice from our top-rated mechanics.

Ask A Mechanic
Over 10,000 questions answered!
  1. Home
  2. Questions
  3. Mixing engine oil causes light knocking in the engine. Should the oil be changed immediately?

Get an instant quote for your car

Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing

Get a quote

What others are asking

Q: Switching to high-mileage oil on PT Cruiser

That's not a high mileage yet, but if you want to, I'm personally a fan of Castrol oil. I use normal Castrol oil and my Toyota’s got 265,000 miles on it. I still use the normal oil. I haven't switched...

Q: Knocking noise from engine and loss of power

The illumination of the check engine light means that diagnostic trouble codes were set during this incident. The codes are probably "related" to the knocking noise. If there was a mechanical failure in the engine, these codes could have simply...

Q: Toyota dealer says I need a new wheel hub & bearing assembly & wants to charge over $500.00! I won't use them but how serious?

Hi Kelly. Thanks for contacting us today. A damaged wheel bearing is a rather serious safety concern. As the bearing loses lubricity, excessive heat is built up, which causes the squealing noise, but also can cause it to snap off...

Related articles

How Do Power Car Windows Increase Passenger Safety?
Power windows are responsible for approximately 2,000 emergency room visits every year. When a power window closes, it exerts enough force to bruise or break bones, crush fingers, or restrict an airway. Though...
What are the Car Pool Rules in Hawaii?
Hawaii is widely regarded as a land of vacation and relaxation, and as such, its scenic roads and routes are far better known than the state’s freeways. But, as with all...
How Much Does a Mechanic Make in Vermont?
Automotive technician jobs in Vermont have an average mechanic salary of $37k, with some mechanics earning a salary of $53k.