Jump to content
  • Sign up for FREE! Become a GM-Trucks.com Member Today!

    In 20 seconds you can become part of the worlds largest and oldest community discussing General Motors, Chevrolet and GMC branded pickups, crossovers, and SUVs. From buying research to owner support, join 1.5 MILLION GM Truck Enthusiasts every month who use GM-Trucks.com as a daily part of their ownership experience. 

2008 5.3 silverado

Recommended Posts

Hi everyone,  i'm new to the forum but not to mechanics, where do i begin. I have a 2008 5.3 AFM (always F&*^(&^ malfunctioning) here's where I'm at and I'll try to be as detailed as possible,  It all started with another collapsed afm lifter ( i had had previously changed the AFM liters when i got the truck and ran great for years)   and up until this point used very little oil,  so i purchased a lifter kit and that included a new VLOM. all new lifters including afm lifters and lifter guides, all new gaskets/head bolts etc...I replaced the oil pump also with a high volume pump/o-ring and primed it, did the valve cover (pcv side) update too! I got the oil pressure up started it up and it  sounded great ran smooth, i noticed blue smoke immediately but it cleared off, after it got halfway up to temp the low oil pressure light came on so i shut the engine off. changed the filter (the filter i used was a mobile 1 filter) ran about 50 miles then same thing happened, low oil pressure light shut off engine and there was an excessive smoke from the exhaust . i shut it off restarted and the oil light went out but there was an excessive amount of blue smoke when i restarted it (i'm sure it's oil because the coolant hasn't moved)  but the oil consumption during those 50 miles was more than a quart and the intake had a puddle of oil when i looked in the plenum and was running rough. i wiped the oil out the next day and unhooked the pcv from the drivers side valve cover and blocked the hose off that goes to the top of the intake but left the valve cover end open, the motor stopped smoking immediately and the cylinders cleared out and started running smooth again but the low iol pressure warning cam back on. the oil Pressure sensor in the vlom is new also, the screen was temp removed but made no difference however the low oil pressure warning came back on, i changed the oil same thing low oil pressure warning . this was a very smooth running engine and used very little oil. has 250k but the cylinders still had visible cross hatching. the only oil pressure component i have not changed (yet) is the pressure relief valve in the oil pan and i would rather not (i'm 55) Lol! but if someone here could let me know if they honestly think that is the issue I will drop the diff/steering rack and remove the pan to change the 10 dollar part!  I haven't done a compression test but that will happen today!  any help would be greatly appreciated and thanks in advance.



Link to comment
Share on other sites

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.


  • Recently Browsing   0 members

    • No registered users viewing this page.
  • Forum Statistics

    Total Topics
    Total Posts
  • Member Statistics

    Total Members
    Most Online
    Newest Member
  • Who's Online   5 Members, 0 Anonymous, 329 Guests (See full list)

  • Create New...

Important Information

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