Q: Knocking when starting from a cold start

asked by on

When I crank my car first thing in the morning after setting all night there is a knocking sound for a few seconds. One mechanic said it was because the oil filter is a sideways one and it takes a second for the oil to get where it needs to be and my other mechanic said it may be the timing chains. Neither one of them can fix the timing chain because they don't have the equipment. But going to the dealer fills my soul with dread!!!! What's your opinion on the knocking. Oh yeah it's been knocking for several months- maybe even a year.....

My car has 120761 miles.
My car has an automatic transmission.

This is somewhat normal as the oil sits down in the oil pan when the car has sat for an extended period of time. When you first start it in the morning, it takes a bit of time for the oil pressure to build allowing the oil to circulate properly throughout the motor. This can cause a bit of knocking and is somewhat normal as long as it does not last too long and is not excessive.

Your vehicle is also equipped with something called a knock sensor which works similar to a microphone listening to the engine and sends signals back to the computer when there is excessive knocking detected. When this happens it retards the timing slightly as a means to protect the motor from potential damage. When this happens it will also trigger the Check Engine Light registering a fault code.

As mentioned above, as long as the knock does not last for an extended period of time, your car should be fine. If you’re avoiding the dealer and would like to have it looked at, consider YourMechanic, as one of our mobile technicians can come to you and diagnose the knocking sound firsthand.

Was this answer helpful?
The statements expressed above are only for informational purposes and should be independently verified. Please see our terms of service for more details
  1. Home
  2. Questions
  3. Knocking when starting from a cold start

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: Q: car does not start

If the door is not latching, there is a switch in the door pillar that may remain in the closed position thus keeping the interior lights on all the time. If that is the issue that is causing the battery...

Q: Dirty throttle body impact on evap purge valve

Hello, the throttle body carbon deposits would not cause the purge valve to fail. The carbon on throttle plate can cause start stall and idle issues that is a service that should be done. The purge valve can fail electrically...

Q: Ac and heater are not blowing air

Hi there: In many cases, the failure of the blower motor to actually blow air into the cabin is caused by a blower motor resistor. This component is usually installed behind the dashboard or underneath the blower motor and can...

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.