Question about 2005 Mazda 6

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I have a knocking noise coming from the engine.

Changed from 87 to 89 octane which has not helped.

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Try de-carboning the engine, I would suggest you use the dealer's brand of chemical to do this, follow the instructions on the can, also check for any computer trouble codes, if no codes and still knocks after cleaning then you may have a connecting rod bearing issue.

Posted on Nov 24, 2008


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What will couse my car to make noise a pinging and knocking type of noise coming from under the hood

Hello Ernie Santacruz,

First best guess is that you are running the
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Some folks try to save a few pennies by running a
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Your question history is only this question...
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Can you clarify WHAT your octance recommendation is...


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Changed out the knock sensor and engine light is still on

Some engine lights don't turn off until the car is driven for awhile. Give it some time. If it doesn't go away, take it to Auto zone to clear the engine code. If it comes back, then it might be a wire problem and not the knock sensor itself. Good luck!

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What is the cause of detonation noise ?

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Jul 21, 2014 | 1995 Mitsubishi Montero

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I have a 2001 Chevy Malibu automatic when it is in first and second gear it makes a knocking sound but when it shifts to third gear it stops I don't think it's a rod knocking because it isn't consent

More information is needed to help with this.

1. Is the knocking coming from the engine, the transmission or elsewhere?

2. If you believe it is from the engine, start the motor and put the auto in neutral and gradually depress the accelerator pedal to gently increase the engine speed for 2 minutes. If you can replicate the knocking noise then obviously it is engine.

3. If the knocking is from the engine check the engine oil level which you should be doing frequently anyhow to ensure you top it up and do not run the oil level low and destroy the motor. (Failure to have the engine oil changed at the required intervals can also result in excessive wear and damage to engine components.) If you do this check and find the oil level is very low then advise here when you repost your query with more information about the source of the knocking sound.

4. Also indicate in your post what grade (octane rating) of fuel you are running the engine on.

Apr 14, 2014 | Cars & Trucks

1 Answer


I am assuming you changed the oil on a regular basis. What type of gas did you put in it? Mine will not run on low octane fuel. Terrible running, an if you have been using wrong octane fuel it will cause damage to that engine. Manual is clear on this as well as dealer.

Mar 27, 2014 | 2004 Cadillac Deville

1 Answer

Knocking noise in engine of 2002 holden rodeo

Hi, is this a new noise ? If it is check the oil level as shown on the dip stick of the engine..... if you can hear knocking the engine will be pretty well buggered. How many km\'s has the vehicle done.... really, not what you can see on the speedo. One other thing is if the wrong fuel has been put in the tank, i.e diesel, or high octane petrol that the knock sensors cannot adjust to suit i.e av gas is a very high octane rating fuel that should not be used in engines designed for low octane.

Dec 20, 2012 | Cars & Trucks

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My lifters rattle like crazy when the motor is cold, but not when it's warm, why?

alot of time this is cause by cheap gas, what i mean is the octane rating 87,89.or 93 if you are using the 87 octane some chevys will rattle on this gas try using the 89 and see what happens if this doesnt help then you could have a bad lifter which would need to be replaced before it does damage to the rest of your engine. hope this helps.

Jan 09, 2011 | 1997 Chevrolet Lumina

1 Answer

When you put truck into gear at an idle (AT) once the truck is warm, I can hear a sharp knocking noise coming from the engine. Injectors have been changed as well as the pump and oil pressure seems to...

Check your engine and transmission mounts. A broken engine mount will mimmick engine knocks. Raise all 4-wheels, and with a partner, have them place the vehicle into gear. Have them accelerate and check the movement of the engine/transmission. They should be not much movement. Visually inspect these mounts for cracks, splits, etc. Removal and replacement is very easy and low cost.
If they check out:
Check your Knock Sensor for voltage and remove and replace if needed.
It could be other things: some are (but not limited to):
Incorrect Fuel Octane Grade.
EGR system malfunction.
Vacuum Leak.
Engine Control System malfunction.

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I have a code # po332 on my 2005 chevy silverado, I cleared it and the code reappeared after two weeks. I use 92 octane fuel and do not hear any knocking noises coming from the engine.

This engine is made to run on 87 octane.Sometimes when using a higher octane can cause a check engine light or other driveability problems.If you don`t think it is your knock sensors then get some used ones at the salvage yard and try them.They are under the upper intake plenum.

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Engine Knocking Noise

This problem in a car this new is likely to be caused by low octane gas. if it doesnt go away after the old gas has been removed and higher octane gas put in then there could be another problem. when does it make the knocking sound? is it only while under heavy load? ie going uphill in higher gears? is it manual or auto?

Jun 16, 2009 | 2005 Scion xA

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