Cold start one second long awful engine sound

[Jettech1]

2022 2500 Chevy gasser......I know this topic has been discussed before, and I know GM said all is good. BUT, I never had that terrible sound until I had the oil changed at the dealer at 2500 miles.  Ever since then, every time I do a cold start I hear this, of what I think, is the timing chain just rattling like heck for a second.  I've checked the oil, it's fine, the dealer of course used a GM oil filter.  There has to be a way to fix this.  I hate it and want to get rid of it, the sound that is....I love the gas engine....best engine ever.  I just want it to not make a horrific noise on start up like it did before I had the oil changed for the first time.  Any ideas how to solve that?

[SWDoodle]

1 hour ago, Jettech1 said:

2022 2500 Chevy gasser......I know this topic has been discussed before, and I know GM said all is good. BUT, I never had that terrible sound until I had the oil changed at the dealer at 2500 miles.  Ever since then, every time I do a cold start I hear this, of what I think, is the timing chain just rattling like heck for a second.  I've checked the oil, it's fine, the dealer of course used a GM oil filter.  There has to be a way to fix this.  I hate it and want to get rid of it, the sound that is....I love the gas engine....best engine ever.  I just want it to not make a horrific noise on start up like it did before I had the oil changed for the first time.  Any ideas how to solve that?

 

My 23 makes the same noise.  Sounds like it’s coming from under the cab?  No idea what it is.  Hopefully its not like the gawd awful noise my 3.5 EcoBoost used to make, but that was cam phasers.  

[Flatus]

My 6.6 gas makes the same noise on cold starts. I explain it the same way, sounds like a timing chain rattle. I was at the dealer last week for an oil change and I brought it up but of course they didn't know what I was talking about. I couldn't leave it there for several hours for them to do a cold start to reproduce it. 

[Jettech1]

1 hour ago, SWDoodle said:

 

My 23 makes the same noise.  Sounds like it’s coming from under the cab?  No idea what it is.  Hopefully its not like the gawd awful noise my 3.5 EcoBoost used to make, but that was cam phasers.  

I had the 3.5 Ecoboost in our 2019 Explorer Sport and never had a problem or noise out of it.  Now, I did my own oil changes and used Mobil 1 with the factory oil filter. 

[Jettech1]

25 minutes ago, Flatus said:

My 6.6 gas makes the same noise on cold starts. I explain it the same way, sounds like a timing chain rattle. I was at the dealer last week for an oil change and I brought it up but of course they didn't know what I was talking about. I couldn't leave it there for several hours for them to do a cold start to reproduce it. 

I'm trying to figure this out...that 6.6L gasser is to die for.  I absolutely love it....But why on earth does it make that noise?  I've read that the oil filter check valve to keep it primed isn't working...I call BS on that theory.  Something changed drastically when my first oil change was done at 2500 miles...  Now what is different?  The only thing different is oil and filter.  Nothing else.  Unless GM put in some kind of additive to their oil......hmmmm...  edit again...I bet GM was using a thicker based oil.  Like a 0 or a 5W-40.....That would make sense for initial break in for an engine that is robust as this one is.

Edited December 1, 2022 by Jettech1

[Flatus]

12 minutes ago, Jettech1 said:

I'm trying to figure this out...that 6.6L gasser is to die for.  I absolutely love it....But why on earth does it make that noise?  I've read that the oil filter check valve to keep it primed isn't working...I call BS on that theory.  Something changed drastically when my first oil change was done at 2500 miles...  Now what is different?  The only thing different is oil and filter.  Nothing else.  Unless GM put in some kind of additive to their oil......hmmmm...

I don't know. I am friends with the service manager at the dealer. I sat down with him in his office and he looked it up in the system to see if he could find any kind of bulletins describing the noise but he could not. I guess I'm just not going to worry about it for now. If it for some reason gets worse, than I will make plans to leave it with them so they can cold start it.

[Jettech1]

1 minute ago, Flatus said:

I don't know. I am friends with the service manager at the dealer. I sat down with him in his office and he looked it up in the system to see if he could find any kind of bulletins describing the noise but he could not. I guess I'm just not going to worry about it for now. If it for some reason gets worse, than I will make plans to leave it with them so they can cold start it.

I'll figure this out and let you all know.  That's what I do.....lol...be well....

[CamGTP]

It's not the oil filter check valve, it's the oil pump itself. It bleeds back and gets air in the veins of the pump. The sound is the pump shoving that air through itself while is sucks up oil to send through the engine.

 

It does no harm to anything and these oil pumps have been doing it since 2014 when the LT engines came out. It's worse if you park on the incline and anything below like 40 degrees outside.

 

If you bought the truck in the summer, you'd never hear it.

[Flatus]

20 minutes ago, CamGTP said:

It's not the oil filter check valve, it's the oil pump itself. It bleeds back and gets air in the veins of the pump. The sound is the pump shoving that air through itself while is sucks up oil to send through the engine.

 

It does no harm to anything and these oil pumps have been doing it since 2014 when the LT engines came out. It's worse if you park on the incline and anything below like 40 degrees outside.

 

If you bought the truck in the summer, you'd never hear it.

It's almost always hot here. I hear it everyday. 

[Jettech1]

26 minutes ago, CamGTP said:

It's not the oil filter check valve, it's the oil pump itself. It bleeds back and gets air in the veins of the pump. The sound is the pump shoving that air through itself while is sucks up oil to send through the engine.

 

It does no harm to anything and these oil pumps have been doing it since 2014 when the LT engines came out. It's worse if you park on the incline and anything below like 40 degrees outside.

 

If you bought the truck in the summer, you'd never hear it.

I did buy it at the end of August which is hot as hell here in Atlanta.  But it immediately started making the noise when I had the oil changed early October.  It never made a peep until then....

[Jettech1]

31 minutes ago, CamGTP said:

It's not the oil filter check valve, it's the oil pump itself. It bleeds back and gets air in the veins of the pump. The sound is the pump shoving that air through itself while is sucks up oil to send through the engine.

 

It does no harm to anything and these oil pumps have been doing it since 2014 when the LT engines came out. It's worse if you park on the incline and anything below like 40 degrees outside.

 

If you bought the truck in the summer, you'd never hear it.

So if that's the case, why did it not do it before I had the first oil change?  That's what has me scratching my head here...it's like, what the hell happened with just an oil change....

[mjm-1957]

Make sure that a PF63 filter is on there and that they used 5-30 oil and not 0-20. I work on the line at a GMC-Buick dealer and can tell you that the oil changes are usually done by the newest inexperienced ****** heads that they can find. Mistakes happen every day. I would not let half of them put air in a bicycle tire. Just something to check.

[Pryme]

I have not heard anything like this and I changed my oil already. 
 

so it is a cold start in both warm and cold air temps?

[It's Tim]

25 minutes ago, mjm-1957 said:

that they used 5-30 oil and not 0-20.

Pray tell how this can be accomplished, perhaps with the Bill Nye science set? 

[newdude]

14 hours ago, Jettech1 said:

2022 2500 Chevy gasser......I know this topic has been discussed before, and I know GM said all is good. BUT, I never had that terrible sound until I had the oil changed at the dealer at 2500 miles.  Ever since then, every time I do a cold start I hear this, of what I think, is the timing chain just rattling like heck for a second.  I've checked the oil, it's fine, the dealer of course used a GM oil filter.  There has to be a way to fix this.  I hate it and want to get rid of it, the sound that is....I love the gas engine....best engine ever.  I just want it to not make a horrific noise on start up like it did before I had the oil changed for the first time.  Any ideas how to solve that?

 

 

Is the oil level good?  On your paperwork, is there a p/n of the oil used?  Did they install a PF-63 filter?  

 

Can you give us a video of a cold start?

 

Without hearing it I'm leaning towards normal.  Its the oil pump that is making the noise.

 

14-06-04-004H: Various Engine Noises During Cold Start and Warm Engine Operation - (May 12, 2022)

 

Oil Pump Cold Start Rrrrp or Rasp

The oil pump design has changed from a gerotor gear type pump to a two-stage vane type pump for fuel economy reasons. At temperatures at or below 0°C (32°F), or when the engine has been sitting for a few hours, it is possible to have air enter the pump through normal oil drain back. Upon startup, the owner may hear a short “Rrrrp” or “Rasp” coming from the front of the engine. It is most often heard during a remote start.

 

There is nothing wrong with the oil pump or oil system. No repairs should be attempted for this condition.

Edited December 1, 2022 by newdude