Jump to content

2018 Sierra 6.2 tough starting

Boyd Proctor

By Boyd Proctor
in Engines & Drivetrain

 Share

Recommended Posts

Boyd Proctor New Member

Boyd Proctor

Posted
Posted
Hey guys,
I have a 2018 Sierra A/T w/ the 6.2, 75000km. I was using a Range AFM disabler but recently stopped. It seems like my truck struggles on cold starts – it takes 4-5 cranks before it will fire up. I replaced the battery as I thought this was this issue but I didn’t help. Cold starts are legit cold starts as in sat outside in -20° C for 12+ hours, it always is plugged in. I’ve also tried to turn the key to on and let the fuel pump prime the fuel system. Once it starts then it’s fine to fire up right away once the key is turned on. Note I was running 87 octane but switched back to 91 octane 2 tanks ago due to the issues.
Is this common for the direct injection engines? It seems like a fuel pressure regulator isn’t properly working but these trucks only have a pressure sensor in the tank?
Any help is appreciated.
M1ck3y Senior Enthusiast

M1ck3y

Posted
Posted

I've experienced something similar. My truck starts better when it hasn't been plugged in; still do when -18 or lower. I don't know the reason for this, but I haven't noticed anything else indicating a problem.

BlaineBug Enthusiast

BlaineBug

Posted
Posted

I've never had this issue but I notice that when the weather is COLD and I'm also using E85 that the cranking is longer than usual.  But maybe by 1 second or so.

M1ck3y Senior Enthusiast

M1ck3y

Posted
Posted
6 hours ago, BlaineBug said:

I've never had this issue but I notice that when the weather is COLD and I'm also using E85 that the cranking is longer than usual.  But maybe by 1 second or so.

 

Yeah, ethanol doesn't like the cold. 

Chris Manchur New Member

Chris Manchur

Posted
Posted

I know exactly what you're talking about, have had the same thing happen on my 2015 6.2L. I'm used to the 2009 Sierra starting up much quicker, so I took a look online and found this service bulletin from a few years ago. 

 

https://static.nhtsa.gov/odi/tsbs/2018/MC-10137203-9999.pdf

 

Apparently the fuel pressure needs to build up which is why it cranks longer than normal, and so far I've started mine in -25 C weather both plugged in and not and it didn't seem to matter.

 

The bulleting mentions it could take up to 5 seconds to start in those temps, and if you count it out that's a long time! However I've always had mine start sooner.

  • Thanks 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing

  • Latest Articles

  • Posts

    • Atlas
      Gas Prices

      By Atlas · Posted

      Those can be high, as well as the big California cities. The ones that will pop your eyes out are the 395 corridor on the Eastern side of the Sierra Nevadas. Lee Vining, $7.19 for regular and $8.89 for diesel is what the Google said right now.
    • newdude
      2020 Trailboss 6.2 replacement

      By newdude · Posted

      Correct.  2019-2021 model years are serviced by a different p/n.  19420611.  Recall 2021s use 19420611.   The recall engines 2022-2024 model years are serviced with 12740076.     The difference between 19420611 and 12740076 is GM changed injector size for 2022.  The injectors are smaller on 12740076 with smaller injector bores in the cylinder heads to match the smaller injectors.  So you can't install a 19420611 in a 2022-2024, and you can't install a 12740076 in a 2019-2021.     Both engines are the replacement engine p/ns that are in the L87 recall.  So both of these are the updated engines.     Here's a version of the L87 recall with the p/ns for all the parts needed.    RCRIT-25V274-7075.pdf   Note it shows 19420611 and 12740076 with an asterisk to a footnote "Use the VIN and the GM Electronic Parts Catalog (EPC) to determine which part to order if two or more part numbers are listed for the same part, as it may vary by vehicle options."    
    • 2017Z
      2020 Trailboss 6.2 replacement

      By 2017Z · Posted

      Looking for advice from this group. Took my flawless 2020 6.2 TB to an unnamed shop for routine rear brakes and oil change. Tech forgot to put oil back in after the full service and needles to say, destroyed my engine.  It’s all on their shop video so they are responsible.   I had my Chevy dealer do the analysis and they confirmed its compromised and said engine replacement. The manager said they only get GM reman engines from GM with full 3 yr warranty and the one they would put in is not same as what’s they are swapping out on 21-25 for recall.    I am looking for advice why that would be a different engine because obviously I had the good 6.2 year and replacing it has my concerns with that recall for 21-15   Also what’s the pros and cons of accepting the engine swap vs telling the shop that bricked the truck to pay up so I buy a new truck. I’m concerned about stigma resale eventually if I just decide to get rid of it after the swap or other issues showing up after the swap out.  
    • GN2018
      AFM Disabler Question

      By GN2018 · Posted

      Just looked up my records.  I've never gone over 5000 miles between oil changes.  At 46K miles, I have 10 oil changes.  I hope that will help.  I also installed the disabler last year.  I've still had a few times when it didn't seem to engage (which I can tell because the start stop feature kicks in), but for the most part, I think it's working.  For some reason, GM did not include the number of cylinders running in the information screen like I had on other models.  In my Cadillac, it shows me when it's running on 4 cylinders on the fuel milage screen.  I can't find that on my '21 Denali.
    • davester
      Wiring Help, Please

      By davester · Posted

      you might read through the info on gmupfitter.com for your truck, to find a good power source.

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...