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

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: Transmission hesitation problems only in reverse

One thing you may want to look at, especially since the transmission has been changed several times, is the shift cable. It is possible that the cable has stretched, and that the transmission may not be fully engaged in reverse....

Q: Knocking from the axle or wheel hub, but no play!

Hello. You have done a great job with the diagnosis this far. Is it coming from the front or the back? Does it get worse going over bumps? From here you should attempt to play around with the suspension some...

Q: Scrubbing noise from front of car.

If the vehicle needs all the ball joints replaced, I would recommend having that done by a professional to see if the noise goes away. The sound is likely occurring due to the excess amount of play in the front...

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...
Rules of the Road For Iowa Drivers
Driving on the roads requires knowledge of the rules, many of which are based on common sense and courtesy. However, even though you know the rules in...
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.