Skip the auto shop - Our mechanics make house calls

Q: Engine knock

asked by on

My dad xplorer is as runner no fine one day we had a great freeze next am been knocking every since My explorer was tuning fine we had a temp drop overnight 2days ago now it knocks so bad I'm afraid to do I've it? What caused this?
My car has an automatic transmission.

Hello. If the engine knock started after a few cold nights then it may be possible that it is related to the engine oil. Engine oil becomes thicker at lower temperatures, which makes it more difficult to pump for the engine the colder it gets. This may result in knocking or lifter noise if the engine struggles to pump the more viscous oil. The noise will usually go away after the engine warms up. I would check the oil to make sure that it is not low, and change it if it is dirty. If you are approaching the colder part of the season then it may also be a good idea to use a lighter weight oil, as lighter oils will flow easier and quicker at lower temperatures. It may also be possible that the knocking may be related to an engine performance issue, though usually the check engine light will come on if this is the case. If you are unsure, I would recommend having a professional technician, such as one from YourMechanic, come to your location to diagnose what may be causing your noises.

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

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. Engine knock

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: power locks won't work on 2003 mercury mountainner

Hello. Thank you for writing in. The first test needs to determine if the power locks work from any of their switches. If both front door panels and the key fob do not unlock the vehicle, then your issue is...

Q: Car engine making sound

It's impossible to say what your engine noise is without hearing it. It could be any number of components each makes it's own trademark sound. But since you say it only makes a sound in gear, I'm going to make...

Q: I have a 2010 ford explorer xls. It turns on but doesnt start or crank.

Hi there. If the security light is flashing when trying to start the vehicle then most of the time this is the result of a failure in the key recognition circuit. It is either the receiver not picking up the...

Related articles

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...
P2428 OBD-II Trouble Code: Exhaust Gas Temperature Too High Bank 1
P2428 code definition A P2428 trouble code signifies that the PCM has detected a problem in the exhaust gas temperature sensor circuit in bank 1, which subsequently contains the number one...
P2103 OBD-II Trouble Code: Throttle Actuator Control Motor Circuit High
P2103 means there is a fault with the throttle actuator control motor circuit, likely due to a defective electrical component or part.