Jump to content

Please help! 2015 GMC Sierra slt 6.2 misfire

Recommended Posts

2015 GMC Sierra slt all terrain w/ 6.2. Engine was running fine then service engine started flashing and traction dash light came on. Engine started misfiring on cylinder 6 swapped coil with cylinder 4 computer still says 6 misfire. I replaced all injectors and spark plug with wire and started engine with same results…I’m going to do a compression test on it tomorrow but is there anything else I could be missing? Thanks 

Link to comment
Share on other sites

Pull the valve covers on that side and see if it's a broken valve spring.  Mine broke on number 5 at 105K miles.  It didn't drop or bend the valve.  So it was a quick and easy fix.  It's pretty common with 6.2's.  They have since updated the design of the valve springs.

Link to comment
Share on other sites

I happens but along as it didn't mess anything else up.  It's a pretty easy fix.  Still sucks I have a love hate relationship with my truck.


Mine broke a valve spring at 105K miles and it was cheap and easy fix.  Then at 125K miles it stuck a lifter.  So I pulled it apart and put a TSP 218/226 in it.  Now I enjoy messing with SS camaro's and mustangs :driving:

  • Like 1
Link to comment
Share on other sites

On 8/24/2021 at 3:07 PM, Joseph J Pahler said:

I was able to feel misfire it was shaking the truck when you gave it gas

Fixed? How many miles? Why did it bend pushrod? Mistimed AFM event? 

Edited by 2018GMC
Link to comment
Share on other sites

  • 1 year later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

  • Create New...

Important Information

By using this site, you agree to our Terms of Use.