Skip the auto shop - Our mechanics make house calls

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?

Need advice from certified mechanic? Get help now!

Over 1000 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
  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: Car won't crank

It appears as if you might have a few non-related problems. If the engine won't crank, this will be due to a battery that is drained or the starter that is damaged. If it cranks but won't start, this could...

Q: I have a 2008 Buick Enclave and the aluminum coolant lines that run under the vechile have been completely severed.

Hi there. Prior to knowing ho much it would cost to repair the system needs to be inspected. If the lines were damaged due to an accident and metal got into the system then it may take more work then...

Q: Brake light bulb sockets fried & melted

Hello there, when bulbs are required to be replaced multiple times like this, there are a few common causes. The most likely would be moisture in the taillight, short-to-power, wiring damage, or a faulty taillight assembly. Generally this is seen...

Related articles

What Causes Hoses to Leak?
While the largest part of your engine is mechanical, hydraulics plays a significant role. You’ll find fluids at work in a number of different areas. Your car's fluids include: Engine oil Transmission...
How Long Does a Heater Control Valve Last?
Keeping the right amount of coolant in a car is essential in keeping the engine at the right temperature. Failing to have the right amount of coolant or even bad elements...
P0240 OBD-II Trouble Code: Turbocharger Boost Sensor B Circuit Range/Performance
P0240 code definition Turbocharger Boost Sensor B Circuit Range/Performance What the P0240 code means P0240 is an OBD-II generic code triggered when the Engine Control Module (ECM) detects the intake boost...