[Rock-It Man]

Originally Posted by PinHead

You're still focusing on the secondary failures not the root cause.

It would take an extremely long and technical post to get into harmonic distortion of hydraulic systems. GM won't admit this as it embarrass their Engineering and Development Teams.

I'll see if I can put into a Cliff Notes version.

A engine's oil system is hydraulic. FACT: The GM AFM is hydraulically controlled and causes harmonic distortion.

Harmonic distortion disrupts and destroys a hydraulic system as well as disrupts a reciprocating assembly's balance.

Lifters without constant pressure cause wear. Excessive wear causes catastrophic failures.

A reciprocating assembly out-of-balance will eventually destroy itself.
http://www.enginebuildermag.com/2013...increase-life/
These two conditions exacerbate the other.


The ONLY fix is to eliminate the harmonic distortion, (i.e. eliminate the AFM system and hard parts).

Btw, Internet Writers also avoid posting about this issue as GM won't play nice ever again.

This informative article about engine balancing has nothing to do with AFM lifters. Rotating parts can be balanced. Lifters move linearly.

[Chutzpah]

Originally Posted by RS-Chevy-SS

That's incorrect. That's same OP posted in here. His engine was replaced and the dealer forgot to put oil in his replacement engine.

While I agree that you shouldn't happy about unexplained noises, maybe everyone should wait for a definitive diagnosis before posting - it's the lifters, the engine is going to blow, I should sell my car etc? Maybe there's an engine issue, maybe not. I DO have the same noise, so I'm definitely not making light of the situation. I saw a post a couple weeks ago and I would have sworn the guys engine was toast. Turns out it was just his belt tearing it self apart..

FYI- I wouldn't have posted if that was the incorrect OP. The guy is still driving his car with not a word about his engine.

Good luck, hope you (and I) get good news today...

[RS-Chevy-SS]

Little update here- I pinged the service writer and got this back

"Believe it or not? We went out this morning after sat over the weekend & no noise. It was quite. So we're letting it sit again & calling technical assistance to see if they have any other cases?"

If they come back saying couldn't duplicate or normal, the car is going to another dealer.

Don't we have a customer service rep in here?

I'm honestly think about pursuing a lemon law or something on this. I've had the car since late January and it's been in the shop so many times

1) headliner popping out of pillar
2) rear camera not working
3) alignment out of spec
4) engine clank noise #1
5) engine clank noise #2
6) Bluetooth microphone sounds bad
7) Bluetooth microphone again

And I still have the rear end groan and the windshield fogging issue.

[Chutzpah]

Originally Posted by RS-Chevy-SS

Little update here- I pinged the service writer and got this back

"Believe it or not? We went out this morning after sat over the weekend & no noise. It was quite. So we're letting it sit again & calling technical assistance to see if they have any other cases?"

If they come back saying couldn't duplicate or normal, the car is going to another dealer.

Don't we have a customer service rep in here?

You may want to find out if they started the car with the a/c on. My car was quite when I started it earlier today, shut off the a/c and I started hearing it again, barely, as the car was almost warmed up. The load or lack there of from the a/c compressor / accessory belt drive could be the cause or possibly masking the noise....when I get out of work I'm going to try it again...

[RS-Chevy-SS]

Originally Posted by Chutzpah

You may want to find out if they started the car with the a/c on. My car was quite when I started it earlier today, shut off the a/c and I started hearing it again, barely, as the car was almost warmed up. The load or lack there of from the a/c compressor / accessory belt drive could be the cause or possibly masking the noise....when I get out of work I'm going to try it again...

I duplicated the noise with or without the AC on.

[Chutzpah]

I just started the car, opened the hood and really listened. The intermittent noises weren't so bad today, but still there (car parked outside in sun over 100f asphalt temp). I'm very much leaning toward thermal expansion of the header heat shields. I'll update if I change my thought process.

[RS-Chevy-SS]

Originally Posted by Chutzpah

I just started the car, opened the hood and really listened. The intermittent noises weren't so bad today, but still there (car parked outside in sun over 100f asphalt temp). I'm very much leaning toward thermal expansion of the header heat shields. I'll update if I change my thought process.

We must have different issues then. My videos were taken in 70° ambient temperature.

[Chutzpah]

All I'm saying is that it appears to be worse when it's cooler outside...In MY case, 70 would be cooler. The engine compartment barely made any metalic clacks this very warm afternoon.

[RS-Chevy-SS]

End of day update - Dealer says they can't hear it. They want to keep it overnight....again.

Told them while they are at it, please perform the rear diff and foggy windshield bulletin as my car suffers from both.

I think I got a lemon.

[Chutzpah]

Originally Posted by RS-Chevy-SS

End of day update - Dealer says they can't hear it. They want to keep it overnight....again.

Told them while they are at it, please perform the rear diff and foggy windshield bulletin as my car suffers from both.

I think I got a lemon.

Sorry to hear that- See links below. One of the LT1 from a couple days ago, I missed videoing the clanking at idle (like yours) Caught the tail end of a drivetrain rapping noise when I revved it up to 1200 rpm. Could be perfectly normal, I'm just not used to my engines sounding like a bucket of bolts (runs awesome though, if that's the way it sounds so be it). The second video is my stang at cold start up, Totally different engines, I know.


https://m.youtube.com/watch?v=5lRYvuCTVI8
https://m.youtube.com/watch?v=HjZjXMYXsmk

[RS-Chevy-SS]

Morning update - I showed up to get a loaner today. Writer said tech still didn't hear anything. I asked to go with the tech to the car. Started it up waiting about a minute or 2 until idle settled. Then it started doing it.

Tech verified the noise and said it sounds bottom end. Said he's going to start tearing into the engine and go from there.

Waiting game.

[Chutzpah]

Originally Posted by RS-Chevy-SS

Morning update - I showed up to get a loaner today. Writer said tech still didn't hear anything. I asked to go with the tech to the car. Started it up waiting about a minute or 2 until idle settled. Then it started doing it.

Tech verified the noise and said it sounds bottom end. Said he's going to start tearing into the engine and go from there.

Waiting game.

That's definitely a bummer...

[soloknight6]

Originally Posted by RS-Chevy-SS

Morning update - I showed up to get a loaner today. Writer said tech still didn't hear anything. I asked to go with the tech to the car. Started it up waiting about a minute or 2 until idle settled. Then it started doing it.

Tech verified the noise and said it sounds bottom end. Said he's going to start tearing into the engine and go from there.

Waiting game.

You are in socal, what dealer is servicing your car if you don't mind my asking.

[RS-Chevy-SS]

Originally Posted by Chutzpah

That's definitely a bummer...

I just want a fixed car I can not worry about. They will probably have it for a while with the motor, rear end, and windshield bulletins.

Originally Posted by soloknight6

You are in socal, what dealer is servicing your car if you don't mind my asking.

PMd