Q: Getting knocking sound when engine is idling from the floor front and side of the engine

asked by on February 01, 2017

2004 Lincoln Aviator knocking sound coming towards the lower front coming from the lower front as well a side of engine. When Engine is in drive and moving beyond 10 miles an hour the knocking stops. And it seems to decrease as the car slows down

My car has 230248 miles.
My car has an automatic transmission.

Noise from engine or exhaust Inspection $79.99 - $89.99 Get a Quote

Hello, thank you for writing in. The knocking is going to sound worse at idle because the number of combustion cycles happening is less than when you are accelerating or maintaining a higher RPM. With that being said, engine knock is most commonly attributed to a poor explosion in the cylinder(s). This can be caused by a spark issues, a fuel issue (like the wrong type of fuel for the engine, or poor fuel quality), bad valve seals, or even a bad knock sensor. All of these components will need to be tested separately. Start with the spark system as it is typically easiest to repair, and it is a heavily uses system that needs constant maintenance. For more help, contact our service department to schedule an appointment.

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

What others are asking

Car overheats, usually in the stop and go traffic

The problem may be due to the hydraulic cooling fan not working intermittently. There is a technical bulletin number 1-21-11 that says to replace the cooling fan hydraulic motor, which should correct the overheating problems. Your fan may work but...

Car bogging down in gear

Hello and thank you for your question. There could be a problem with the brakes not releasing or the transmission torque converter could have failed. Check all of the brakes and make sure that they are adjusted and working properly....

Blown engine in a 1999 Lincoln town car

Hi there. Unfortunately, our mobile mechanics are not able to complete engine replacement services, so we would be unable to offer you an estimate for this service. Generally speaking however, a replacement engine that has been refurbished by a professional...

No sound when I turn the on the ignition

In my opinion, it sounds like the charging system is not recharging the battery. It is most likely the alternator, but only a test can tell. These vehicles have had many electrical issues with instrument clusters and wiring harness problems...

When AC is on I hear a beeping noise

Hello. Small beeps when the AC is on can be caused by dirty or faulty AC components. A common source of a beeping or chirping sound when the AC is turned on is a dirty or faulty evaporator case. The...

How to turn off front seat passenger side airbag

The passenger front seat air bag cannot be disabled unless there is no weight in the seat, or the entire system is disabled which is unsafe. The system looks for weight in the seat to determine if there is an...

hello Brandon my name is Marie,I have a 2005 pontiac bonniville gxp Im having crankshaft issues and oxygen sensors

Hi Marie: With regard to the code P1372 that was downloaded, there are many potential malfunctions that will cause P1372 to set in addition to the crankshaft position sensor itself being faulty. And, if the sensor itself is suspected as...

Broken timing belt

Your Jetta's engine is what is known as an "interference" motor which means that when the timing belt breaks, the valve train typically will sustain major damage. This usually involves bent valves and many other problems and can be very...

I'm getting these error codes : 2f4f, 4F81, 4F84, 4F8F

Based on the codes, one of the more likely failures relates to a break in the mechatronic sealing sleeve and adapter (BMW parts nos. 24347588725 and 24347588724). Of course there are other and additional possibilities but such can only be...

Related articles

What Does It Mean When an Engine "Knocks"?
If your engine is making a knocking noise it means there's a problem. The wrong fuel octane, carbon buildup, and bad spark plugs can cause knocking.
What Does It Mean When an Engine "Knocks"?
If your engine is making a knocking noise it means there's a problem. The wrong fuel octane, carbon buildup, and bad spark plugs can cause knocking.
How Long Does an EGR Control Solenoid Last?
In In order to help reduce the amount of engine emissions cars have what is called an EGR system, which is an exhaust gas recirculation system. The way it works is that exhaust gas is added back into the fuel/air...