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Discussion Starter · #1 ·
Hello guys,
I've noticed this rattle coming from the engine. (2007 2.3l)
It's especially present at cold start and then around 2-3000 rpm.
Car has done about 300.000km and have had oil and filter changes regularly.

I've looked around ind the forum but haven't been able to diagnose the exact promlem at there seem to be many causes... Do any of you guys recognize this sound? (It is not the engine mount)

I've added the soundclip below 馃憤
Sound clip
 

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I dont know and its a video, youd need to have someone you can trust listen to it in person.
 

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2004 Mazda 6s Wagon ATX
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Hello guys,
I've noticed this rattle coming from the engine. (2007 2.3l)
It's especially present at cold start and then around 2-3000 rpm.
Car has done about 300.000km and have had oil and filter changes regularly.

I've looked around ind the forum but haven't been able to diagnose the exact promlem at there seem to be many causes... Do any of you guys recognize this sound? (It is not the engine mount)

I've added the soundclip below 馃憤
Sound clip
@Byakuya

I would agree with @TalonTsi90 and say rod knock. It is not as prominent because there is still just enough journal/bearing pressure to keep it from contacting, except when you rev the motor. Putting the extra fuel in to accelerate the engine increases the force enough to make contact. Notice it does not do this when the motor is spinning un-loaded (not accelerating).
I suppose it could also be valves but you can check that I believe pretty easily. A heavier weight oil (short term) might make that clack go away it is is rod bearings.
Good luck.
 

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Discussion Starter · #7 ·
@Byakuya

I would agree with @TalonTsi90 and say rod knock. It is not as prominent because there is still just enough journal/bearing pressure to keep it from contacting, except when you rev the motor. Putting the extra fuel in to accelerate the engine increases the force enough to make contact. Notice it does not do this when the motor is spinning un-loaded (not accelerating).
I suppose it could also be valves but you can check that I believe pretty easily. A heavier weight oil (short term) might make that clack go away it is is rod bearings.
Good luck.
Thank you for your input... Sound like I'll have to have a look at the bearings, was hoping it could be the timing chain slapping against the cover but it does sound like it might be coming from inside the engine so I am thi king rod Knock unfortunately too...
 

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Well鈥 that doesn鈥檛 sound very good.

Simple checks for things like loose or failing accessories (alternator, power steering pump, A/C compressor, even crank pulley dampener) would be worthwhile, but otherwise based simply on the vid it sounds internal to the engine to me. Rod bearings is a reasonable guess, I think.
 
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2014 Mazda 6 GT & 2006 Mazda 6 GT-MT HB
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I also first thought it was rod knock but I can't explain is why the noise goes away at higher rpms... when I was a teenager I drove car with rod knocking until it self destroyed and died and I recall it was crazy loud and got worse as the rpms increased.

Read this. and this. Not saying this is your case but...

I suggest you buy one of these stethoscopes and find out exactly where the noise is coming from.
 

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Hello guys,
I've noticed this rattle coming from the engine. (2007 2.3l)
It's especially present at cold start and then around 2-3000 rpm.
Car has done about 300.000km and have had oil and filter changes regularly.

I've looked around ind the forum but haven't been able to diagnose the exact promlem at there seem to be many causes... Do any of you guys recognize this sound? (It is not the engine mount)

I've added the soundclip below 馃憤
Sound clip
Hate to say it but that's rod knock. My 6 was doing that and my mechanic put it on the rack with his guy in it and listened with a stethoscope. I had it on Cylinder 1. Made that noise at the exact same RPM too, around 3k. Not present at idle or higher than 3250 or so. I had mine rebuilt and haven't had an issue since. All new internals. It could go another 100k miles or it could fail completely tomorrow, you just never know.
 
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