Jump to content

Another AFM issue?

g2full

By g2full
in Troubleshooting & Recalls

 Share

Recommended Posts

g2full Enthusiast

g2full

Posted
Posted

So, decided to beat on my truck a little last night, which I don't do often but from time to time I do stretch its' legs a bit.

 

Threw a check engine light and could feel a misfire.

 

So, pulled codes and sure enough misfire on cylinder #7. Today I swapped plugs and wires, cleared the code and fired it back up to have the same results. Pulled codes again - cylinder #7 misfire. Swapped coil packs around and the misfire stayed on #7. 

 

Did a compression test - just a hair under 125 on cylinder #7. I didn't check the other cylinders, at this point I'm frustrated. 

 

New plug is oil soaked from a 10 mile drive. 

 

No obscure noises coming from the engine. Could this be an AFM lifter issue?

 

I do have a Zurich powertrain and will be taking it to the dealer tomorrow. Just want some opinions from the knowledge here.

 

Thanks!

 

15 Silverado 5.3 non flex fuel motor. 78k miles on it.

 

g2full Enthusiast

g2full

Posted
  • Author
Posted
7 minutes ago, Lsgun1 said:

Oil soaked or fuel soaked? Oil shouldn't enter a cylinder if it's a lifter issue.

Pretty sure oil. I mean, it smelt like raw fuel for sure. But was black and oily. Was able to sling it off the plug even.

g2full Enthusiast

g2full

Posted
  • Author
Posted

What should I be seeing numbers wise on the compression test? I have tried searching but can't seem to find anything.

Lsgun1 Enthusiast

Lsgun1

Posted
Posted (edited)

A lifter collapse would just not open a valve it wouldn't get oil in the cylinder. If oil is getting in it's potentially piston rings, valve seals or a head/head gasket problem. You're going to have to dive deeper in. I'd start looking at the injectors just since we've seen enough failures that it could just be dumping fuel in and maybe is mixing with the carbon on the tip of the plug to turn whatever liquid is in there a darker color.

Edited by Lsgun1
Slash L86 Enthusiast

Slash L86

Posted
Posted (edited)

If I ever(fingers crossed) get a ce light for engine misfire then that bitch is getting towed (assuming still under warranty or extended? )directly to the nearest dealer. 

Oil on plug sounds to me (and I'm by no means qualified to even answer) like a gasket or o ring. Exhaust smoking? 

 

I did own a 93 isuzu rodeo that had some weird issue with defective plug boot wires and some oil was in the plug area when I tuned it. Never got a ce or misfire from it though. That was a real long time ago.

 

With these engines and all the computer shit it could really be anything causing it.

My suggestion would be get a good (if you already don't have one) extended warranty on it and read it to see if have to wait certain time to bring it in.

Edited by Slash L86
g2full Enthusiast

g2full

Posted
  • Author
Posted

Thanks for all the replies everyone. It's going in today as I do have a Zurich powertrain. I'll keep everyone updated on the cause for sure.

 

After this (depending on the outcome) if the truck is fixed I will be tuning out the AFM. 

 

 

g2full Enthusiast

g2full

Posted
  • Author
Posted

Dropped off at the dealer. They're saying they can't look at it until next week so we will see. Tech was talking with advisor when I dropped it off and he seems confident with explaining the issue and what I've already done that it's either a lifter or piston.

 

 

g2full Enthusiast

g2full

Posted
  • Author
Posted

Dealer called back. 

 

Failed lifter and bent push rod. 

 

Seems that GM is picking up the bill. Writer made it seem as if it was under a warranty extension. I believe I"m still going to look to tune out the AFM.

 

  • Like 1
g2full Enthusiast

g2full

Posted
  • Author
Posted

Another update - 

 

 

Truck came back today. They did 2 lifters, the solenoid valley pan thing that controls the AFM lifters, Head Gasket, Oil Change, and Push Rod.

 

 

Was speaking with the tech and he's concerned that I also have an injector failing. He said my one fuel trim is at 18% and typically he likes to see plus or minus 5% of 0. 

 

My concerns are - injectors aren't covered under my extended warranty/powertrain. Second concern is that I just ordered my Autocal and if I have an injector issue obviously I'll need to sort that out before I get it tuned. While running in the shop it actually came down 2%(to the 18%) so maybe the truck is just un happy that everything was apart?

 

What is everyones thoughts and or suggestions at this point?

 

ksiesel Enthusiast

ksiesel

Posted
Posted

I thought I read on here that GM extended the injector coverage on the K2xx GDI injectors.  I’m sure if you do a search, you’ll find something about it.

g2full Enthusiast

g2full

Posted
  • Author
Posted
33 minutes ago, ksiesel said:

I thought I read on here that GM extended the injector coverage on the K2xx GDI injectors.  I’m sure if you do a search, you’ll find something about it.

It would be awesome if they did. Thank you. I’ll look around. 

bg1988 Enthusiast

bg1988

Posted
Posted
On 10/27/2019 at 3:01 PM, g2full said:

So, decided to beat on my truck a little last night, which I don't do often but from time to time I do stretch its' legs a bit.

 

Threw a check engine light and could feel a misfire.

 

So, pulled codes and sure enough misfire on cylinder #7. Today I swapped plugs and wires, cleared the code and fired it back up to have the same results. Pulled codes again - cylinder #7 misfire. Swapped coil packs around and the misfire stayed on #7. 

 

Did a compression test - just a hair under 125 on cylinder #7. I didn't check the other cylinders, at this point I'm frustrated. 

 

New plug is oil soaked from a 10 mile drive. 

 

No obscure noises coming from the engine. Could this be an AFM lifter issue?

 

I do have a Zurich powertrain and will be taking it to the dealer tomorrow. Just want some opinions from the knowledge here.

 

Thanks!

 

15 Silverado 5.3 non flex fuel motor. 78k miles on it.

 

what is the OCI for that 78k?

g2full Enthusiast

g2full

Posted
  • Author
Posted
30 minutes ago, bg1988 said:

what is the OCI for that 78k?


Since I’ve had it at 64k 11 months time frame I’ve only done 3. Truck was actually on a fresh change when this happened. 
 

I try to stick around 5k but I also pay attention to the maintenance minder. 

bg1988 Enthusiast

bg1988

Posted
Posted
16 minutes ago, g2full said:


Since I’ve had it at 64k 11 months time frame I’ve only done 3. Truck was actually on a fresh change when this happened. 
 

I try to stick around 5k but I also pay attention to the maintenance minder. 

5k is good you have 8qt

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
      OCI, not when but why?

      By Atlas · Posted

      On the subject of OLM, Gm's OLM tool may be more "informed" than others brands. I recall OLM's in mid-2000's Chrysler products literally counting down a set number of miles. That's all the OLM appeared to be.    I would actually expect GM to be able to explain the parameters that their OLM takes into account from a high level. No, I would not expect them to disclose their software coding or data analysis around their parameters.   So we're talking about two different topics, so to continue the subject on the other one, I'd be curious to know how much "standard particulate matter" in fresh oil is able to be filtered at first start by a fresh oil filter. How much particulate matter is enough to "matter"?   I.e. how much of a "lever" do we think this equates to (variability in particulate content, in fresh oils, between different makes/brands, some which filter less, and some that filter more).   We can say that more particles = more wear = shorter engine life as a logical statement and use that data with a little marketing to scare people into selecting a more refined/filtered oil. Using a similie, is this like deciding to forego two alcoholic drinks in a lifetime because we're worried about the potential impact on lifespan? Are there numbers which translate the ISO test results into a quantifiable increase in wear for a given engine/use case?
    • chris21
      Brand new to this forum. Questions about re-gearing my 26’ HD

      By chris21 · Posted

      I'm pretty sure it doesn't actually recalibrate the speedometer it just changes the wheel speed sensor inputs to the computer. The truck still thinks it has stock tires.
    • asilverblazer
      OCI, not when but why?

      By asilverblazer · Posted

      I apologize, I missed this post, at risk of going off CURRENT TOPIC.   I'm not saying it is BS, I'm questioning how much information is being held back. GM is NOT going to spell out exactly every parameter in the algorithm. Liability, intellectual property, etc.    I'm not naive enough to believe that it is as simple as revolutions, coolant temperature, miles, time; are you?    I don't do irrational either, and boiling the OLM down to four simple values that I could code in an afternoon (I'm not a coder) is irrational - unless it suits your agenda to ignore it. 
    • BDS my HD
      Brand new to this forum. Questions about re-gearing my 26’ HD

      By BDS my HD · Posted

      Chris 21 I appreciate your constructive response. !!  😉😉😉   The 6.6 is gas.  Correct me if I’m wrong but by recalibrating the speedo you’re correcting the shift points of the transmission on these trucks.?.
    • newdude
      Brand new to this forum. Questions about re-gearing my 26’ HD

      By newdude · Posted

      That is a huge misconception.     Bigger does not always equal safer.  Modifying does not make it safer either, with exceptions.   Think of this.  Your truck in stock form is capable of emergency maneuvers, proper stopping distances, its handling is designed around the factory wheel/tire packages, etc.   37s and a lift?  Now you've affected your braking distances, handling and ride control.  You've raised your center of gravity higher.  Your front visibility is now obstructed more than stock, same for your rear.  Does it look cooler?  Yes.  Does it now work as good as it did from factory on road?  NO.       As for my mention of exceptions?  Say you had a sedan or crossover.  They typically come with all season tires.  If you swap out for a performance all season or a summer tire, you improve your car by lowering its stopping distance (better braking because of traction) and improve the handling (regular and emergency) of the vehicle.  That is an actually improving modification.  My old 2019 LD 1500, I ran UHP all season tires on 20in wheels in a factory offered size.  It improved all aspects of how it drove over the Duratracs it came with from the factory in the stock 18" tire.  

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...