Notices
PCM Diagnostics & Tuning HP Tuners | Diablo | Pantera EFI

Normal knock retard on l92?

 
Old 05-13-2018, 02:57 PM
  #1  
TECH Apprentice
Thread Starter
iTrader: (2)
 
warriorpluto's Avatar
 
Join Date: Jul 2010
Posts: 316
Default Normal knock retard on l92?

I have an 2007 Yukon Denali and I used my torque app to see what truck was doing since I haven't played around with the app in a while. I have stock tune on it. With ac on while cruising I was getting knock the whole time on the five mile trip ranging from 0.1 up to 4.7 degrees while cruising. Is this normal? Iat was 97 degrees on the highway. Temp outside is 91 degrees. When going up hills is knock retard normal on these trucks that much? Even when on flat roads with the AC on?
warriorpluto is offline  
Old 05-13-2018, 03:06 PM
  #2  
TECH Apprentice
Thread Starter
iTrader: (2)
 
warriorpluto's Avatar
 
Join Date: Jul 2010
Posts: 316
Default

I wanted you add that my truck knocks after it warms up then after a drive down the street it stops knocking. Not piston slap. This is a very deep knock. I've put about 15k miles on it since then in a year. I'm sure if it were something serious the engine would've let go a long time ago. I've been all in deep texas and lousiana. Makes great power.
warriorpluto is offline  
Old 05-14-2018, 12:20 AM
  #3  
TECH Apprentice
Thread Starter
iTrader: (2)
 
warriorpluto's Avatar
 
Join Date: Jul 2010
Posts: 316
Default

https://youtu.be/RKIXgwqEU0o
warriorpluto is offline  
Old 05-14-2018, 12:21 AM
  #4  
TECH Apprentice
Thread Starter
iTrader: (2)
 
warriorpluto's Avatar
 
Join Date: Jul 2010
Posts: 316
Default



This was the old spark plug I pulled out
warriorpluto is offline  
Old 05-28-2018, 07:46 AM
  #5  
TECH Apprentice
Thread Starter
iTrader: (2)
 
warriorpluto's Avatar
 
Join Date: Jul 2010
Posts: 316
Default

? I also had injectors cleaned and services. What what could cause this?
warriorpluto is offline  
Old 06-03-2018, 06:52 AM
  #6  
TECH Senior Member
iTrader: (3)
 
Old Geezer's Avatar
 
Join Date: Jun 2004
Location: GA, USA
Posts: 5,365
Default

Fuel psi is?
Old Geezer is offline  
Old 06-05-2018, 09:42 PM
  #7  
TECH Apprentice
Thread Starter
iTrader: (2)
 
warriorpluto's Avatar
 
Join Date: Jul 2010
Posts: 316
Default

Originally Posted by Old Geezer View Post
Fuel psi is?
Key on engine off 50 pounds. Key on engine on sixty pounds. I'll recheck again tomorrow
warriorpluto is offline  
Old 01-25-2019, 10:12 PM
  #8  
TECH Apprentice
Thread Starter
iTrader: (2)
 
warriorpluto's Avatar
 
Join Date: Jul 2010
Posts: 316
Default

If it helps i screen recorded what i go through. Just want to know of this is normal. I was in the middle of an three hour trip going 80mph at 2000 rpm. Again this is an 2007 yukon denali. Turn volume down

https://drive.google.com/file/d/1iyd4iLqBMJ_GG8Jn_0Ar3HXNy1viw2xt/view?usp=drivesdk
warriorpluto is offline  
Old 02-01-2019, 03:09 AM
  #9  
Staging Lane
 
Lethalwx69's Avatar
 
Join Date: Apr 2014
Posts: 53
Default

Are you using 91 octane or greater? Also is there a stock tune on the car?
Lethalwx69 is offline  
Old 02-07-2019, 10:53 PM
  #10  
TECH Apprentice
Thread Starter
iTrader: (2)
 
warriorpluto's Avatar
 
Join Date: Jul 2010
Posts: 316
Default

Originally Posted by Lethalwx69 View Post
Are you using 91 octane or greater? Also is there a stock tune on the car?
I'm using 93 shell. Thats the only fuel use and yes it's stock tune
warriorpluto is offline  
Old 02-13-2019, 04:46 AM
  #11  
Staging Lane
 
Lethalwx69's Avatar
 
Join Date: Apr 2014
Posts: 53
Default

Originally Posted by warriorpluto View Post
I'm using 93 shell. Thats the only fuel use and yes it's stock tune
You should move to using a copper core spark plug like a NGK tr55 instead of, my guess, iridium.
Lethalwx69 is offline  
Old 02-13-2019, 08:45 AM
  #12  
Staging Lane
 
DFORESI's Avatar
 
Join Date: Jan 2019
Location: Detroit, Michigan
Posts: 56
Default

I'm still a bit new to the GM stuff but from my understanding 4 degrees of ignition retard is still in the acceptable range. Although I will agree that 0 would be better. You would expect to see some KR value if you were running regular fuel, but premium should prevent that.

I supposed it's possible that your MAF is dirty and reporting lower airflow than actual. This would definitely cause the system to pull timing. Do you have HP Tuners? Can you force the car into SD mode and log again?

If not, I suggest trying to clean the MAF with sensor safe cleaner.
DFORESI is offline  
Old 02-13-2019, 11:27 AM
  #13  
cam
TECH Junkie
iTrader: (9)
 
Join Date: Apr 2004
Location: in the garage
Posts: 3,166
Default

Clean maf is cheap and fast. Id follow that up with a new fuel filter and maybe even get injectors cleaned and flowed. These engines are fairly high SCR and the pistons are large so theres not a lot of room for meh when it comes to your air fuel set up so if any of the components fall out of range this sounds normal to me. So long as the ECM is pulling timing and your not hearing any actual knock its probably pretty safe. Its hard to keep these things running as new. My old GMT800's are always pulling timing nowadays. Still run good though, just not all that fast anymore
cam is offline  
Old 04-09-2019, 10:11 AM
  #14  
TECH Apprentice
Thread Starter
iTrader: (2)
 
warriorpluto's Avatar
 
Join Date: Jul 2010
Posts: 316
Default

Originally Posted by DFORESI View Post
I'm still a bit new to the GM stuff but from my understanding 4 degrees of ignition retard is still in the acceptable range. Although I will agree that 0 would be better. You would expect to see some KR value if you were running regular fuel, but premium should prevent that.

I supposed it's possible that your MAF is dirty and reporting lower airflow than actual. This would definitely cause the system to pull timing. Do you have HP Tuners? Can you force the car into SD mode and log again?

If not, I suggest trying to clean the MAF with sensor safe cleaner.
I didn't get a notification for your reply, but I'll try to clean it this weekend
warriorpluto is offline  
Old 04-09-2019, 10:15 AM
  #15  
TECH Apprentice
Thread Starter
iTrader: (2)
 
warriorpluto's Avatar
 
Join Date: Jul 2010
Posts: 316
Default

Originally Posted by cam View Post
Clean maf is cheap and fast. Id follow that up with a new fuel filter and maybe even get injectors cleaned and flowed. These engines are fairly high SCR and the pistons are large so theres not a lot of room for meh when it comes to your air fuel set up so if any of the components fall out of range this sounds normal to me. So long as the ECM is pulling timing and your not hearing any actual knock its probably pretty safe. Its hard to keep these things running as new. My old GMT800's are always pulling timing nowadays. Still run good though, just not all that fast anymore
I changed the injectors already. One went bad and i just changed the whole set out with rebuilt injectors from a reputable company. I'm not sure if this was happening before or after the injector swap. I swore i did a torque log when i first got the truck and didn't see allot of knock retard. Only after. So i may change the injectors again just to be sure. I'll update the thread after cleaning the maf
warriorpluto is offline  
 


Thread Tools
Search this Thread

About Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description:
Your question will be posted in: