Jump to content

2009 6.2L Engine knocking.

Shaun Toole
 Share

Recommended Posts

Shaun Toole Enthusiast

Shaun Toole

Posted
Posted

My apologies for the selection on year but I’m hoping someone has experienced the noise I’m hearing. I bought a 2009 Yukon Denali with the 6.2L and it has a knock that seems harmonic with cylinder 6 and also audible through the water pump. When the rpm’s are increased above idle it sounds like marbles in a can. The only code (and no light) is a p0011. Engine oil pressure at idle is just below 20 and at 25 when rpm’s are brought up (seems low).
 

Immediately after purchase I have done the following;

1. Oil change with sea foam detergent. 

2. Oil pressure sensor.

3. Full swap and inspection of lifters. There was no obvious damage.

4. Cleaned push rods.

5. New plugs and wires.

5.b Changed oil again after 10 minutes of idle.

6. Clean and inspect Oil timing valve.

7. Replace VVT solenoid.

8. Replace Camshaft positioning sensor.

 

The engine idles well at 550 but knocks loudly. At any increase it sounds like marbles. Any thoughts on what I should be looking for?

 

  • Sad 1
CamGTP Senior Enthusiast

CamGTP

Posted
Posted

If all you get is 25psi of oil pressure at like 1500-2000+ rpm I'd say something in the lower end is going bad. With the knocking sound you hear it could be a bad bearing.

 

Without me there in person to hear the sound, it's tough to guess at it.

  • Like 1
swathdiver Senior Enthusiast

swathdiver

Posted
Posted

Yeah, can you take a video, post to youtube and link it here?

 

Marbles is usually a bad cat or a heavy marbles sound is the flex plate or torque converter bolts.

 

Now you said that you installed new lifters or moved them from one side of the engine to the other?

 

What brand, weight and amount of oil have you been using?  Which oil filter?  These are questions for the post-mortem.

Z45 Senior Enthusiast

Z45

Posted
Posted
Quote

1. Oil change with sea foam detergent. 

Snake oil.  

  • Like 1
Shaun Toole Enthusiast

Shaun Toole

Posted
  • Author
Posted

 Here’s a video of the knock. 


A couple of updates since the post. All check engine lights are clear, the OBD code is p0011. Just incase it was advanced, I checked resistance and output of the knock sensors and replaced them.

 

The oil pressure has increased at idle to ~32-35 at cold start. The flush oil and the current new oil is Castrol Full synthetic with a STP filter 5w30.

 

All of the lifters are new, all of the push rods cleaned straight, all of the rockers and springs appeared to be in good condition.

newdude Senior Enthusiast

newdude

Posted
Posted

That sounds like a broken valve spring or a shot cam.  

 

Or its a rod about ready to depart the block.

 

Either way, time to open it up.  

 

 

  • Like 1
Shaun Toole Enthusiast

Shaun Toole

Posted
  • Author
Posted
On 5/25/2023 at 12:40 PM, elcamino said:

Snake oil.  

What is snake oil? I’m am certain all of the issues when I bought it were tied to poor maintenance with the oil.

Shaun Toole Enthusiast

Shaun Toole

Posted
  • Author
Posted
59 minutes ago, newdude said:

That sounds like a broken valve spring or a shot cam.  

 

Or its a rod about ready to depart the block.

 

Either way, time to open it up.  

 

 

Then that is what I shall do! Is it possible to get to the rod bearings without pulling the engine? Or is it best to do a full exploratory inspection?

  • Like 1
CamGTP Senior Enthusiast

CamGTP

Posted
Posted

You can remove the front diff and the front crossmember under the oil pan, then remove the oil pan to check all the rod bearings.

  • Like 1
newdude Senior Enthusiast

newdude

Posted
Posted (edited)
16 hours ago, Shaun Toole said:

What is snake oil? I’m am certain all of the issues when I bought it were tied to poor maintenance with the oil.

 

 

Products in a can or bottle that "claim to fix" certain problems.  STP, Motor Honey, Bars Leak, etc.   

 

Olden day term that's still used today for sleazy con salesman back in the day who went around selling elixirs that would cure all sorts of ailments and diseases.  

Edited by newdude
  • Like 2
KARNUT Senior Enthusiast

KARNUT

Posted
Posted
7 minutes ago, newdude said:

 

 

Products in a can or bottle that "claim to fix" certain problems.  STP, Motor Honey, Bars Leak, etc.   

 

Olden day term that's still used today for sleazy con salesman back in the day who went around selling elixirs that would cure all sorts of ailments and diseases.  

I’ve used all those products. I’ve used stp in heavy equipment gear boxes. As far as bars leak it’s keeping me from having to fix cracks in my heads going past a year now. A common problem in some 5.3s. On the road bars leak has gotten me home. I had an experience drag racing against my brothers little red express truck years ago at raceway park in Baytown TX. I was driving a 69 GTS dart with a 340. Shifting into 4th edging my brother at the line I heard it knocking. Two cans of STP went in and I drove 70 miles home. I gently drove it on Saturdays for 6 months around the block until I got bored and sold it. Did STP help? I wouldn’t bet against it.

  • Like 1
Grumpy Bear Senior Enthusiast

Grumpy Bear

Posted
Posted (edited)

GM sells a motor flush and a top end soak to free rings. They also sell a radiator pellet to seal leaks. Similar products to Bars leak, KREEN and GUNK Motor Flush. Crutches if you will. 

 

Then we have products that actually cure issues. Red Line MTL was developed to cure the lack of a useful first gear synchromesh in 80/90's Honda 5 speed manual gearboxes. A transmission with a synchromesh first that would not go into low gear above 2-3 mph would do so from any speed you felt comfortable shifting into. Handy in a gymkhana event or winding mountain road. Rain-X original..... Cerakote..... Red Line Shockproof Heavy....... HPL SAE30/40 EC....... All products that fix things....and do it well. Techron and product like it. Red Line S-1, AMSOIL P.I. 

 

Then we have some real losers. Z-Max and Slick 50 come to mind. It's not that they don't work. It's that they don't work for long and in the case of the chlorinated solvent, can cause damage. Snake oil.

 

Snake oil makes claims it cannot produce or produce for as long as stated. 

 

 

Edited by Grumpy Bear
diyer2 Senior Enthusiast

diyer2

Posted
Posted

What you need is a whim wham for a water wheel.

  • Haha 1
Grumpy Bear Senior Enthusiast

Grumpy Bear

Posted
Posted
2 hours ago, diyer2 said:

What you need is a whim wham for a water wheel.

 

Na, a bucket of steam will fix it.

  • Like 1
swathdiver Senior Enthusiast

swathdiver

Posted
Posted
On 5/26/2023 at 3:22 PM, Shaun Toole said:

 Here’s a video of the knock. 

 

 

That's not normal nor normal here.  Shut it down and start by taking off the rocker covers and inspecting the valve train for bend pushrods, broken springs, etc.  I have a bad feeling that the problem lies deeper though, like a connecting rod or piston.

 

Fellas, should he do a compression test first?  Inspect the plugs first and do a compression test.

  • Like 2

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

    250.4k
    Total Topics
    2.7m
    Total Posts

  • Member Statistics

    342,759
    Total Members
    8,960
    Most Online
    DM22
    Newest Member
    DM22
    Joined

  • Who's Online   2 Members, 0 Anonymous, 2,875 Guests (See full list)

  • Latest Articles

  • Posts

    • Chuck FB
      summer road trips in the 2026 2500HD

      By Chuck FB · Posted

      I thought I would use your thread and add to it as I just did my first longer drive with my truck in the last couple of days. I drove from the Grande Prairie area of Alberta down to Edmonton and most of where I drove in the city was the ring road so fairly free flowing but a bit of stop and go as well in the city. Stayed the night and returned home and not too many stops along the way each way but every restart and certainly every cold start sets it back for fuel mileage. Why I say that is I see some people will cherry pick a fuel mileage leg after the vehicle had been warmed up driveline wise before hand and its a forgiving ( easy rolling drive leg for example ) and call that their fuel mileage which can give a false perception of reality. I was not heavily loaded at all but never the less the flip bak cover, rubber bed mat, various tools etc and extra jerry cans of fuel all way up to a few hundred pounds of dead weight so its not an empty truck. The cold inflation tire pressures are set more near the freezing point so once they are warmed up driving I was showing 45 front and over 40 rear and realize high inflation pressures would help a little in fuel mileage but certainly not the ride on our crap sections of highway. The weather was good so was not raining as that can really drag mileage down, in fact I had a bit of a tail wind on average driving home. Most people on here would never have driven on that freeway to visualize it but its got a fair bit of rolling type of landscape with numerous river valleys. For the most part I had it on cruise set to 62 although kicking it off if I caught it in time before it started down shifting and self braking going down the grades. Most of the more substantial grades its shifting into 7th I believe as 8th just doesn't have it. Total distance round trip was 643 miles and my overall average and I did refuel three times in all, figured out to 17.65 miles per US gallon. My best fuel mileage section refuel within all of this figured out to 18.46 and these are all hand calculated figures. I find if anything that the trucks computer can be over optimistic, sometimes its pretty close but other times its stretching it. On paper persay in theory the truck would have just about made it on fumes for that whole drive without refueling once.    Which made me think of the topic thread of the wonder if these trucks could do 20 mpg and that is a good question, certainly would have to be on an easy going flat highway, no head wind, the right temperature, not packing around a bunch of dead weight and puttering along even slower than I was I would suspect and going steady and not stopping to smell the flowers or take a piss !. It probably is possible but not without effort to attain that with the wind resistance and weight of these trucks. Of course on my drive most people are passing me if they have the power as per loaded highway tractors, never mind a lot of speedy vehicles but the speed limit is 68 and most are at or well over that. 
    • Aimatdeer
      Ac not keeping up

      By Aimatdeer · Posted

      Monday looks like a good day for the dealer to test an ac issue. Hopefully it all turns out good.
    • CamGTP
      Gas Prices

      By CamGTP · Posted

      Paid $2.72 for E85 today.
    • Atlas
      Gas Prices

      By Atlas · Posted

      Welcome back! No, it definitely doesn't pass the sniff test. Even "ceasefire" needs an alternative definition these days.    $5.29 at Kroger today
    • bluev8
      Intermittent no-code issues on 2022.5+ V8 trucks — what did the shop fail to capture?

      By bluev8 · Posted

      That makes sense, and I think you are describing the real product problem. Capturing data is the easy part. If the owner or technician has to manually dig through five minutes of millisecond-level logs, the product has already failed. The device would be at the ECM harness, not at the OBD port, so I agree that data retrieval and event marking need to be thought through carefully. The way I am thinking about the architecture is: The recorder itself should not depend on a phone, app, Bluetooth, Wi-Fi, or cloud connection to capture the event. It should always keep a local rolling buffer and lock the event locally. A button, phone app, or small cabin device would only act as an event marker. If the driver feels a stumble and presses the button 10–30 seconds later, the pre-buffer has to already contain the useful data. For data retrieval, the practical options would be a sealed service USB lead, Wi-Fi download, or a phone/cabin companion device. I would not expect the owner to remove the ECM-side module or work with raw files directly. The cloud or AI side would be for interpretation, not for capturing the event. The truck may have no connection when the issue happens, so the evidence has to be saved locally first. After that, cloud processing could help decode the data, compare it against baselines, and generate a readable report. For the first version, I would keep the automatic triggers conservative and objective: driver event marker bus-off error passive voltage drop / brownout device reset FIFO or queue overflow a normally periodic message disappearing side-to-side communication mismatch, if the topology supports that For “learning normal,” I agree with your point, but I would not want to overclaim it as automatic root-cause diagnosis at first. A realistic first step would be learned baseline comparison for that specific vehicle and operating condition. For example, a value would only be compared against similar conditions: RPM range load / MAP throttle position gear / vehicle speed coolant and oil temperature battery voltage AFM/DFM state, if decoded and validated Then the report could flag things like: this periodic message disappeared compared with its normal timing this value deviated from this vehicle’s normal range under similar conditions the same abnormal pattern repeated after the same type of event the anomaly occurred together with voltage, oil-pressure, misfire, or communication changes But I would still call that “abnormal pattern detected,” not “replace this part,” unless there is enough validated repair data behind it. So the intended product would not be “here is a huge log.” It would need to be an event package: what triggered the capture how much pre/post data was preserved what changed before and after the event whether the device itself reset, overflowed, or saw a bus error selected graphs around the event raw data only as supporting evidence From your perspective, what would make this kind of report useful instead of just another datalog? For example: What are the top 5 parameters or events you would want highlighted first? Would you trust a learned baseline for that specific vehicle, or would you prefer fixed thresholds? How much false-positive flagging would be acceptable before you stopped looking at the reports? What would a one-page report need to show for an independent shop to take it seriously? For misfire, AFM/DFM, oil pressure, or U-code complaints, what would you want the tool to flag automatically?

  • GM-Trucks.com Clubs

  • Popular Contributors

×
×
  • Create New...