Lifter knocking in the morning

[Scotts]

Lately I have been noticing lifter knocking at low rpm in the mornings. Mostly when pulling away from stop lights but goes away when rpms go up.
Also, probably unrelated but transmission has been shifting weird and now it is difficult to move the shifter into park.
I also have the rough idle stuff but have had that since I got the car and the dealer can't duplicate.
2013 M56s with 20,000 miles.
already have had timing chain recall and a new a/c compressor. starting to get bummed
I can't figure it should be normal?

[Frog]

Are u sure it's lifter knock and not pre ignition? If it's combined with ruff idle you could need a de carb treatment. However it's for sure knock then de carb treatment won't help

[Snake31]

Lately I have been noticing lifter knocking at low rpm in the mornings. Mostly when pulling away from stop lights but goes away when rpms go up.
Also, probably unrelated but transmission has been shifting weird and now it is difficult to move the shifter into park.
I also have the rough idle stuff but have had that since I got the car and the dealer can't duplicate.
2013 M56s with 20,000 miles.
already have had timing chain recall and a new a/c compressor. starting to get bummed
I can't figure it should be normal?

Scotts,
Have you been able to resolve your problem? My car makes similar noises upon the first one or two takeoffs after warmup then goes away. I also experience a lot of engine drone in the 1500-2500 rpm range. City fuel economy is about 12.5 on average when I do not include warm up time. I have had the dealer perform the decarb service at 18500 miles but this did not help.

[DFW2011M56S]

My $0.02. I have had 3 different 5.6 engines now and they all make some extra noises when cold. The MLS exhaust manifold gaskets take a little heat to seal on a cold morning and you can often hear noticeable tapping like sounds from the minor exhaust leaks. Also our direct injection pump and injectors are just plain obnoxious and loud. The fuel delivery is higher than normal with a cold engine which makes it more pronounced. My M56 spends the first 45 seconds or so in open loop and has a very different noise than when it goes into closed loop. Standing outside of the car you can hear the tone change.

[Ilya]

My $0.02. I have had 3 different 5.6 engines now and they all make some extra noises when cold. The MLS exhaust manifold gaskets take a little heat to seal on a cold morning and you can often hear noticeable tapping like sounds from the minor exhaust leaks. Also our direct injection pump and injectors are just plain obnoxious and loud. The fuel delivery is higher than normal with a cold engine which makes it more pronounced. My M56 spends the first 45 seconds or so in open loop and has a very different noise than when it goes into closed loop. Standing outside of the car you can hear the tone change.

Most engines have a pronounced changed from open to closed loop...hell even my Kawasaki motorcycles. My 2013 Ninja ZX-6R was VERY pronounced...I knew the exact moment when it changed and that's usually when I started to ride it.

[DFW2011M56S]

My $0.02. I have had 3 different 5.6 engines now and they all make some extra noises when cold. The MLS exhaust manifold gaskets take a little heat to seal on a cold morning and you can often hear noticeable tapping like sounds from the minor exhaust leaks. Also our direct injection pump and injectors are just plain obnoxious and loud. The fuel delivery is higher than normal with a cold engine which makes it more pronounced. My M56 spends the first 45 seconds or so in open loop and has a very different noise than when it goes into closed loop. Standing outside of the car you can hear the tone change.

Most engines have a pronounced changed from open to closed loop...hell even my Kawasaki motorcycles. My 2013 Ninja ZX-6R was VERY pronounced...I knew the exact moment when it changed and that's usually when I started to ride it.

My old 350 chevy is not noticeable and the Titans were also less noticeable. But the M56 is very obvious.

[Snake31]

So I have hated driving my M56x nearly the entire time that I have owned it. But now this feeling has passed. The car has been sluggish nearly every time I drove it for the last 7 months. I would have excessive valvetrain noise, subtle vibration in the gas pedal, and my fuel economy was about 10% less than it should have been. I ended up resetting the two AFMs and now the car purrs and for the first time I was able to break the car loose on wet pavement.

The procedure was:
Warm car up and then turn off
Disconnect both AFM connectors
Start engine and run until DTCs for AFMs are displayed
Turn car off
Reconnect AFM connectors
Start engine and run at idle for more than 10 min

[Ilya]

So I have hated driving my M56x nearly the entire time that I have owned it. But now this feeling has passed. The car has been sluggish nearly every time I drove it for the last 7 months. I would have excessive valvetrain noise, subtle vibration in the gas pedal, and my fuel economy was about 10% less than it should have been. I ended up resetting the two AFMs and now the car purrs and for the first time I was able to break the car loose on wet pavement.

The procedure was:
Warm car up and then turn off
Disconnect both AFM connectors
Start engine and run until DTCs for AFMs are displayed
Turn car off
Reconnect AFM connectors
Start engine and run at idle for more than 10 min

AFM connectors are the ones on the intake before the intake tubes?

[Snake31]

That is correct. Also please note that I left out a step in my previous post. I cleared the DTC before restarting the engine.

[Ilya]

That is correct. Also please note that I left out a step in my previous post. I cleared the DTC before restarting the engine.

I'll have to try this for S&G's.

[NRGM45]

Is this the noise you guys are talking about on cold mornings ?

https://www.youtube.com/watch?v=vDSsa0TBzyE

[Ilya]

I ended up doing the AFM reset but didn't know anything crazy different and didn't give it the beans yet. It might have idled better upon first startup...but could be placebo.

[Snake31]

Is this the noise you guys are talking about on cold mornings ?

https://www.youtube.com/watch?v=vDSsa0TBzyE

No that is not the same sound. My sound was occurring during the first two accelerations from a stop after warmup. It was independent of temperature for me. I noticed it even when I would take off for lunch on warmer days.