Engine noise - lifter, rod, ?????

[Geoffsfas10]

OK, so here is my engine noise. Its very quiet but you can hear it in the video. It started in maybe june or so after i replaced my 02 sensor. Its not an exhaust leak though. It only happens about 2k rpm and it hard to hear above 3k. It really only audible when the windows are closed and i can hear it then. Oil is regularly changed at 3k miles, with mobil 1 5w-30 and wix filter. oil is clear and clean, plenty of power is there, gas mileage is normal, no smoke or anything out the exhaust. Just wanting to get your ideas. Going to pull the valve covers tomorrow sometime with my neighbor and see if that shows us anything. Im guessing its a lifter, it sounds like its drivers side, plugs to cylinder 1 and 7 were kinda gross when I changed them about 1500 miles ago. That had no real effect on the noise. seems to quiet to be a rod knock, theres also no CEL or warnings up, truck has 91k on it. Neighbor thinks it might be a stuck lifter from carbon build up from poor maintaince from old owner but im open to ideas. Hopefully its an easy fix, supposed to drive it to PA in a month.

 

[George B]

Do you have a tech2? If so you can dial the engine speed up to 2,000 RPM and hold it so you can crawl around and listen for it better.

 

[Geoffsfas10]

Do you have a tech2? If so you can dial the engine speed up to 2,000 RPM and hold it so you can crawl around and listen for it better.

i do not, but my neighbor might. I have also heard that since this is a 14, the tech2 might not be able to communicate with it

 

[Geotrash]

Definitely mechanical, and somewhat irregular. My money is on something on the top end like a loose rocker arm or possibly the flex plate. If you have a mechanic's stethoscope, you could nose around the front of the engine too and listen for bad bearings in an accessory.

 

[iamdub]

Definitely doesn't sound like an exhaust leak, unfortunately. It sounds like slack in the drivetrain, like a loose rocker or broken spring. Grab a mechanic's stethoscope and listen around while someone operates the throttle. It seems a bit "fast" for 2K RPM- listen to the front cover cuz the timing chain tensioner is thin enough to make such a higher-pitched sound.

 

[Geoffsfas10]

Sounds good. Im sure my neighbor has one of those as well. To preface this some more, my neighbor is the head mechanic at a honda dealership in town amd operates side work out of his garage. So we get do this work in a heated garage with a 2 post lift and all his tools. Wont be a bad deal

 

[iamdub]

OK, so here is my engine noise. Its very quiet but you can hear it in the video. It started in maybe june or so after i replaced my 02 sensor. Its not an exhaust leak though. It only happens about 2k rpm and it hard to hear above 3k. It really only audible when the windows are closed and i can hear it then. Oil is regularly changed at 3k miles, with mobil 1 5w-30 and wix filter. oil is clear and clean, plenty of power is there, gas mileage is normal, no smoke or anything out the exhaust. Just wanting to get your ideas. Going to pull the valve covers tomorrow sometime with my neighbor and see if that shows us anything. Im guessing its a lifter, it sounds like its drivers side, plugs to cylinder 1 and 7 were kinda gross when I changed them about 1500 miles ago. That had no real effect on the noise. seems to quiet to be a rod knock, theres also no CEL or warnings up, truck has 91k on it. Neighbor thinks it might be a stuck lifter from carbon build up from poor maintaince from old owner but im open to ideas. Hopefully its an easy fix, supposed to drive it to PA in a month.

Based on the sound (at least, as I hear it through these old laptop speakers) and form your post in the other thread:

See that was my initial thought because i feel like to started to notice this after i had the code for a bad o2 sensor. i replaced it and its on the same side that I replaced the sensor but its very much a metal on metal noise. But IMO, its WAY to quiet/inconsistent for a rod knock

Here's the other thing thats super confusing, on the highway in 6th gear, i sit at 1500 rpm at 60 ( 3.08 gears ) and it doesnt make the sound. If i down shift into 5th to go up a hill and i get to 2k rpm, no sound. going up a BIG hill hill it will go to 4th and i will hear what sounds like an exhaust leak at 2500ish to about 3k but thats all the longer i generally stay in it, it shifts back up and gets quiet. There is no audible difference it switching back and forth between 4 and 8 mode, only difference i see if the tach drops maybe 100-200 rpm.

I'm leaning towards busted timing tensioner. Different loads will change the way the timing chain whips out, so it's not strictly RPM-dependent. I'd go fishing for pieces through the oil pan's drain hole. Maybe use a telescoping magnet for a lure.

 

[Geoffsfas10]

Based on the sound (at least, as I hear it through these old laptop speakers) and form your post in the other thread:



I'm leaning towards busted timing tensioner. Different loads will change the way the timing chain whips out, so it's not strictly RPM-dependent. I'd go fishing for pieces through the oil pan's drain hole. Maybe use a telescoping magnet for a lure.

Interesting theroy. I did an oil change last weekend or maybe the weekend before and theres nothing thats come out. Still will investigate.

It does seem like it sounds like its coming from around the #7 cylinder. I can try a different video, was just trying to not make anyone motion sick from moving the camera around

 

[Geoffsfas10]

So this is interesting. I was talking to my boss about this noise and we went and listened to it and it almost sounds like it might be an accessory making the noise. Its rhythmic with the engine, but it doesnt make the rhythm of the engine. Since on decelleration is kind comes and goes. He thinks it might be the alternator, so I might try reving it real quick with the serpentine belt off to see if it still happens or not.

 

[iamdub]

So this is interesting. I was talking to my boss about this noise and we went and listened to it and it almost sounds like it might be an accessory making the noise. Its rhythmic with the engine, but it doesnt make the rhythm of the engine. Since on decelleration is kind comes and goes. He thinks it might be the alternator, so I might try reving it real quick with the serpentine belt off to see if it still happens or not.

Dammit. I thought you had already tried it with the belt off.
Bearings in an accessory drive sounds plausible since it's frequency doesn't seem to match valve events.