Jump to content

Cylinder 7 low compression

Javy

By Javy
in Troubleshooting & Recalls

 Share

Recommended Posts

Javy New Member

Javy

Posted
Posted

Hy guys I'm new to the page hoping to find some answers. I have a 2014 chevy Silverado ltz 5.3 with low compression on number 7 cylinder it all started leaving a restaurant from having dinner I mashed on it hard pulling into the highway and the engine light started flashing and stabilitrac lights came on made it home and parked it next morning I hooked my scanner up and seen #7 was misfiring so I pulled the plug to inspect it and it had a little bit of oil on it and looked old so I went ahead and replaced them all and nothing changed so I swapped coil and wire with #1 and the misfire didn't change so right away I thought a afm lifter failed so I pulled the valve cover of and both rockers where moving fine so did a compression test and only get about 25 pounds at idle so today I decided to pull the head off and inspect the piston cylinder and lifters and everything seems fine valve and springs seem fine to besides some carbon buildup so now I don't know what direction to go hopefully some one here can point me in the right direction also cam lobes look good too

  • 2 weeks later...
Ozer Enthusiast

Ozer

Posted
Posted

What did you end up doing with this issue?

What year and miles are you, under warranty?

Ozer Enthusiast

Ozer

Posted
Posted
21 hours ago, BigBadSierra said:

Cylinder 7 is an AFM cylinder so most likely a lifter failure.

he said " I thought a afm lifter failed so I pulled the valve cover of and both rockers where moving fine " so it may not be the case.

BigBadSierra Senior Enthusiast

BigBadSierra

Posted
Posted
32 minutes ago, Ozer said:

he said " I thought a afm lifter failed so I pulled the valve cover of and both rockers where moving fine " so it may not be the case.

It may not be locked but sticking so it’s letting cylinder pressure drop.  They don’t always collapse.  If it is sticking it will eventually get stuck and collapse. 

  • Like 1
  • 2 weeks later...
avidsailor Enthusiast

avidsailor

Posted
Posted

I did not have any codes but my mileage went sideways. My mechanic stated that it is an internal problem and that I need to have the engine rebuilt.

  • 5 years later...
Timothy0159 New Member

Timothy0159

Posted
Posted

I seem to have a similar problem with my 2011 Cadillac Escalade EXT.  compression test shows about 42 on number 7 but the rest have around 54-57 while running.    Someone told me to put a can of trans fluid into the oil and run it a while and it may loosen up the sticky lifters.  If anyone sees this,  what are your thoughts?

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

  • Recently Browsing   0 members

    • No registered users viewing this page.

  • Forum Statistics

    250.5k
    Total Topics
    2.7m
    Total Posts

  • Member Statistics

    342,951
    Total Members
    8,960
    Most Online
    Afennell19
    Newest Member
    Afennell19
    Joined

  • Who's Online   0 Members, 0 Anonymous, 876 Guests (See full list)

    • There are no registered users currently online

  • Latest Articles

  • Posts

    • Grumpy Bear
      The Peckish Synapse

      By Grumpy Bear · Posted

      Breaking News!    I'm going to tell you that I'm going to tell you.  Then I'm going to tell you what I'm going to tell you.  Then I'm going to tell you.  Then I'm going to tell you what I told  you.  Then I'm going to tell you what I'm about to tell you on the other side of the break.  Then we're going to break. Then I'm not going to tell you what I told you I was going to tell you.  But I'll tell you something else that is Breaking News just coming to the desk that everyone reported on yesterday.  Then I'll tease a human interest telling I'll get to on the other side of a larger break. Then I'll tell you one item in 20 seconds and go back to an even longer break. Longest break of the night.  Then I'll tell you a fluff piece that takes 10 seconds and sign off into a three minute break while you wait for the next 30 minutes of rinse and repeat on the local news.    In al you'll get about 12 minutes of something, 5 minutes of which is worth hearing in a 30 minute show and 18 minutes of advertising at a sound level twice as loud as the news.    Of course you can switch to cable news and hear 12 different people tell the same four stories in much the same format as the Network News for 20 hours of which the majority will be advertising.  And four hours of late night Specials about things you wonder why you stayed up to listen to. Half of which will be repeats.....   OR you can go for a drive  
    • Afennell19
      Audio Dampening and quiet

      By Afennell19 · Posted

      Did you ever figure this out? My 2022 Trail Boss, and now my 2026 LT did this from time to time.  I believe it was more connected to Android Auto and my phone being the cause. Maybe try going for a drive, sans cell phone.... and see if it happens? 
    • Afennell19
      2026 Sierra 1500 Denali - Sound upgrade?

      By Afennell19 · Posted

      I have a 2026 Silverado LT, the non bose as well.  Upgrading the door speakers is pretty straightforward. You could honestly go to walmart, or Auto Zone/ O Reilly and get a set of 6x9s for the front, and 6.5s for the rear. You do also have to get some adapters for each, but they are like $10 a pair on Amazon. Then some plug and play harnesses that are about $10 a pair on Amazon as well.  And I would also suggest a 10 pack of the Amazon Basics sound deadening. Slap that all around the speakers and on the open metal of the inside of the door. And your golden.   I am currently doing this with my Silverado. Although I am having a bit of trouble because I am snooby I guess and bought some Alpine S2 S69c's which are 2 way components and I am having to wire from the door up to the dash....  Having never installed speakers before, its taking me just a bit to get everything correct. But if you dont buy expensive component speakers, and just some $40-$50 door speakers. You will DRASTICALLY improve the sound over these stock paper cone junk speakers. I thought my Silverado had an issue with the radio/ sound for a while.  Come to find out.  The stock speakers are just THAT SH*TTY   I cannot wait to have some decent sound in the truck   What did you end up doing?
    • newdude
      Parking Brake - Automatic Engagement Questions

      By newdude · Posted

      Its all automatic based on yaw sensor data.  If enough incline is detected, it engages.   My recommendation though would be to disengage it before driving off and not let it auto disengage by touching the gas pedal.  The HD trucks use the same setup as prior years, the drum in hat park brake.  But now with an electric actuator.  If you drive off repeatedly over time, it can torque the park brake shoes and can also prematurely wear them out.           Electric console shift will set the park brake on flat ground too.  Pretty sure they've got it programmed to activate every time.  
    • riddler
      Supercharger (whipple)

      By riddler · Posted

      Anyone install a a supercharger on your 6.6L L8T? Talk to me...

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...