Chirping? noise when accelerating

[Music Junkie]

I have a 2014 Silverado LTZ (very high milage - 219,000)  Runs great and still has some power left under the hood.  For the most part, it is in great shape.  It have a strange noise when acceleration or getting up to about 3 or 4 thousand RPM.  It only does it under load, so it is hard to find where the noise is coming from.  In the attached video, it takes place at 12-18s and then again at 40-46s.  It is hard to hear because of the wind noise, but I can't figure out how to isolate the noise any better.  If anyone has any ideas, I would sure appreciate the input.  The water pump was just replaced, and so was the alternator, along with the tensioner pulley.  I admit my limited knowledge under the hood, but I am willing to learn and fix it, if I can.

 

https://youtu.be/PctCm6Ai09Y

[sdeeter19555]

Have the universal joints been replaced? A dry joint will cause a squeak/chatter as it seizes up.

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[Darmichar]

Does it change with engine speed?  What I could hear, sounded like the beginnings of a bearing drying out.  Maybe belt tensioner idler or alternator.

[Music Junkie]

Not to my knowledge.  I will check with the boss.  It is his old pickup that was handed down to me.  If that could be it, that is fairly easy to fix.  Thanks for the input!

[mookdoc6]

55 minutes ago, Music Junkie said:

I have a 2014 Silverado LTZ (very high milage - 219,000)  Runs great and still has some power left under the hood.  For the most part, it is in great shape.  It have a strange noise when acceleration or getting up to about 3 or 4 thousand RPM.  It only does it under load, so it is hard to find where the noise is coming from.  In the attached video, it takes place at 12-18s and then again at 40-46s.  It is hard to hear because of the wind noise, but I can't figure out how to isolate the noise any better.  If anyone has any ideas, I would sure appreciate the input.  The water pump was just replaced, and so was the alternator, along with the tensioner pulley.  I admit my limited knowledge under the hood, but I am willing to learn and fix it, if I can.

 

https://youtu.be/PctCm6Ai09Y

219K?  No lifter failures?  AFM still running?  Nobody would believe this....

[Music Junkie]

4 minutes ago, Darmichar said:

Does it change with engine speed?  What I could hear, sounded like the beginnings of a bearing drying out.  Maybe belt tensioner idler or alternator.

It starts mostly when getting up to 3,000 to 4,000 rpms and stays pretty constant if I keep it there.  If I let off of the gas, it stops instantly.  If I step back on, it starts up again.  Cruising around town at slower speeds and less rpm's does not start it up.  Once I let off of the gas and then ease back on it on the freeway, I can keep it from happening most times.  It really is just when it is under heavier acceleration.  I hope that makes sense.  Alternator was just replaced last weekend, and the water pump and tension pulley were replaced about 3 months ago.  Figured we would replace the tension pulley while we were in there.

Edited June 26, 2019 by Music Junkie
forgot something

[Darmichar]

2 minutes ago, Music Junkie said:

I hope that makes sense.

That does, and I agree with @sdeeter19555, I'd take a look at the condition of the U-joints in the driveshafts.  It sounds like it's 'tension' based and the most common place for that to happen is the driveline.

[Music Junkie]

4 minutes ago, mookdoc6 said:

219K?  No lifter failures?  AFM still running?  Nobody would believe this....

Pardon my ignorance, but if it was lifters, would it make the sound while rev'd up in neutral?  It only does it while under load (in drive).  I have tried to replicate it while power braking, but it won't do it.  There seems to be an engine safety mechanism in place.  Also, I will have to read up on AFM, as I do not know what that is, at least not by the acronym.

[Music Junkie]

4 minutes ago, Darmichar said:

That does, and I agree with @sdeeter19555, I'd take a look at the condition of the U-joints in the driveshafts.  It sounds like it's 'tension' based and the most common place for that to happen is the driveline.

Thanks!  I hope it is something like this, that can be fixed without too much trouble.

[Music Junkie]

16 minutes ago, Music Junkie said:

Pardon my ignorance, but if it was lifters, would it make the sound while rev'd up in neutral?  It only does it while under load (in drive).  I have tried to replicate it while power braking, but it won't do it.  There seems to be an engine safety mechanism in place.  Also, I will have to read up on AFM, as I do not know what that is, at least not by the acronym.

O.K., AFM is for the management when the cylinders cut off from 8 to 4.  That system has not been replaced to my knowledge.  Could that cause this problem?

[aseibel]

30 minutes ago, mookdoc6 said:

219K?  No lifter failures?  AFM still running?  Nobody would believe this....

5 minutes ago, Music Junkie said:

O.K., AFM is for the management when the cylinders cut off from 8 to 4.  That system has not been replaced to my knowledge.  Could that cause this problem?

Hes just asking because this is very high mileage for this truck model. People have wondered about the longevity of the engine with AFM activated. Some people deactivate it because they fear it will cause problems long term.

 

You're not using Canadian KM measurements are you? 219K Miles is a lot for 5 or 6 year old truck.

 

 

 

[Music Junkie]

On 6/26/2019 at 9:30 AM, aseibel said:

Hes just asking because this is very high mileage for this truck model. People have wondered about the longevity of the engine with AFM activated. Some people deactivate it because they fear it will cause problems long term.

 

You're not using Canadian KM measurements are you? 219K Miles is a lot for 5 or 6 year old truck.

 

 

 

Nope, all US units....  My boss does a TON of driving for work, and replaces his truck every 5-7 years, as his mileage is quite high.  The body and interior are immaculate.  The engine does have a little noise when you first start it up, until the oil gets moving, but nothing very bad.  All in all it is a great truck.  Better than the old one I drove, 2003 Silverado 1500 LT with 174k miles - still have that one and will pass it on to my youngest son who will start driving in 6 months....lol.  I know every mile on that one and it is still nice as well.  This one is just nicer inside.  I don't complain about any of them, as they are company trucks and I don't have to pay for anything.  Quite the deal as far as I am concerned.  Since they take care of me, I like to take care of the trucks and don't mind working on them when I need to.  Figure that is a fair trade off.

Edited June 27, 2019 by Music Junkie
spelling error

[Lsgun1]

I'd take the belts off and drive it.

[Music Junkie]

O.K., I was able to make a couple more sound samples yesterday, and this morning.  I tried recording them with the windows up and the A/C and radio off to see if I could isolate the noise a bit more.  It is a bit clearer.  I also kept on it a bit and then let off and pressed again to show how it slows down and speeds up with acceleration.  Maybe these sound bites will be better.

 

 

[Darmichar]

That sounds like it could be the flapper valve oscillating with the exhaust.  I'd clamp it open and drive the truck and see if it stops making the noise.