Need help with engine noise

Tech discussions on the L77 6.0L V8.
jackleg
Posts: 99
Joined: Wed May 04, 2016 9:25 pm
Location: SW MI

Need help with engine noise

Post by jackleg »

Just posted up an into here viewtopic.php?f=2&t=1289" onclick="window.open(this.href);return false;

So I picked up my 2011 a couple days ago and am trying to diagnose the engine noise.
Here's a video if you all could take a look (listen) and tell me what you think, I'd really appreciate it.
Cold engine sounds perfect, just injectors ticking. After its warmed up theres a steady light knock sound at idle. Just a little bit of throttle and it quiets down and doesn't change with load like a rod bearing does with light on and off throttle in neutral.
I tried grounding out the coils one by one and the sound does not change so I'm thinking maybe a lifter but its heavier than just a "tick" sound.

https://www.youtube.com/watch?v=3V2sjYQg4YA" onclick="window.open(this.href);return false;
2011 9C1 6.0
RCR "Little Lunati" 219/223 .625/.625 112+0
Kooks headers, hi flow cats, Dynomax Super Turbos
Flex fuel tune
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elc32955
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Re: Need help with engine noise

Post by elc32955 »

Do you still have powertrain warranty on the car by chance? Methinks one of the AFM lifters is not a happy camper...
System Manager and your tour guide for the day. 2015 Caprice w/LFX, former NC DPS staff car. Partial hybrid G8/SS/Camaro SS interior mods, SS MyLink radio upgrade, 2016 Camaro V6 rims, GMPP Malibu chrome exhaust tips, otherwise bone stock for now.
jackleg
Posts: 99
Joined: Wed May 04, 2016 9:25 pm
Location: SW MI

Re: Need help with engine noise

Post by jackleg »

140k miles- No warranty.
I'm probably going to pull the engine and take it apart to have a look. I 'm going to get a few more people to listen to it and do a compression test first- get as much info as possible before disassembly.
been reading the posts about DOD delete and cam upgrades. hopefully the lifter bosses in the block are OK. Maybe new cam and lifters, chain set, oil pump and crank bearings? Ill have to track all these parts down.. I've been out of the business for almost 10 years (good to be back!). I'll be posting the progress along the way with plenty of questions.
The goal is to have a car that's a badass daily driver.
Thanks
2011 9C1 6.0
RCR "Little Lunati" 219/223 .625/.625 112+0
Kooks headers, hi flow cats, Dynomax Super Turbos
Flex fuel tune
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bsparks72
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Location: Katy, Tx

Re: Need help with engine noise

Post by bsparks72 »

I'm willing to bet if you do the DOD delete and get some lifters in there, you'll be fine.
-Brandon
2012 9C1 L77 - 228/234, .604/.609 112 cam, JBA shorty headers, Solo high-flow cats, X-pipe, Cherry Bomb single-chamber mufflers (Frankenstein exhaust), Roto-Fab CAI, CTS-V torque converter, 3.45 Camaro diff, G8 red/black seats/steering wheel
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storm9c1
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Re: Need help with engine noise

Post by storm9c1 »

Since the cam turns at half speed of the crank, and I counted roughly 300 clicks per minute (which is 600 RPM crank speed), my guess is that's definitely a cam/lifter noise. I agree with everyone else, tear it apart, new non-AFM lifters, check or replace the cam, good to go. As long as the cam itself doesn't go flat and spread metal bits through the engine. I know it sounds like it's quite a bit of work, but the AFM lifters are problematic on these cars with high miles.
Tom (AKA: Storm)
2011 Caprice 9C3: L77, 8K miles, first-owner, purchased July 2011.
1995 Caprice 9C1: LT1, 178K miles, summer car.
1995 Impala SS: LT1, 21K miles.
1995 Caprice Wagon: LT1, 62K miles.
1995 Caprice Wagon: LT1, 128K miles. Rust In Pieces
1994 Caprice 9C1: LT1, beater winter car.
1969 Chevy C30: 383ci stroker, 4L80E, rollback car hauler.
1972 Chrysler Newport: 400ci big block, survivor 27K miles, 2-door hardtop.
1969 Dodge Charger: 383ci big block.
jackleg
Posts: 99
Joined: Wed May 04, 2016 9:25 pm
Location: SW MI

Re: Need help with engine noise

Post by jackleg »

Got a vacation coming up- looks like I'll be spending it in the garage!
I think I'll go ahead and pull the engine and take it apart to see what it's made of.
Been reading up on the DOD delete threads- seems like the thing to do
Only thing is.. what to do for a cam, so many choices.
Looking at the Lunati 60516, 219/223, 112 LSA -OR- Comp Cams XR 269HR 216/220 114 LSA, any input is welcome. I'd rather someone tell my I'm a dumbass than end up with a dorked up engine! A "kit" with all the parts that will work together would be perfect.
I need to be able to drive this car daily and plan to keep the stock converter and exhaust- maybe delete the mufflers.
I Don't know any tuners, the Black Bear Performance tuning looks interesting.
Thanks for the replies.
2011 9C1 6.0
RCR "Little Lunati" 219/223 .625/.625 112+0
Kooks headers, hi flow cats, Dynomax Super Turbos
Flex fuel tune
CrashTestDummy
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Re: Need help with engine noise

Post by CrashTestDummy »

Black Bear said they could do it. They tuned our Tahoe, and it's great.

I'd call the vendors for those DOD delete kits. Most are knowledgeable of their cams and LS engines, and can make a decent recommendation based on your intended use.
Gene Beaird,
Pearland, Texas
2012 Caprice 9C1
1992 B4C 1LE Camaro
2018 Tahoe PPV (her car)
1995 DGGM Impala SS
1985 Firebird - 310 LS1 C Prepared autocross car.
1980 Bluebird Wanderlodge
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jackleg
Posts: 99
Joined: Wed May 04, 2016 9:25 pm
Location: SW MI

Re: Need help with engine noise

Post by jackleg »

Got started pulling the engine out today, not as much progress as I hoped- spent a lot of time getting the shop organized. Should have it out and apart tomorrow. I haven't ordered parts yet, Hopefully I can do DOD delete, cam, lifters, springs, rings, bearings.
I Think I'm going with the "Little Lunati" cam. I been told there's 2 versions one for LS3 intake valves, the other for standard valves. 219/223 .625/.625 112+0 -or- 219/223 .612/.615 112+1.
I'm still trying to learn about these engines- The L77 has the rectangle port heads, so I'm thinking these are the LS3 heads and valves?
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2011 9C1 6.0
RCR "Little Lunati" 219/223 .625/.625 112+0
Kooks headers, hi flow cats, Dynomax Super Turbos
Flex fuel tune
User avatar
bsparks72
Posts: 284
Joined: Tue Jan 20, 2015 9:29 pm
Location: Katy, Tx

Re: Need help with engine noise

Post by bsparks72 »

Yeah, when cam shopping pretend it's an LS3. I think you're on the right track.
-Brandon
2012 9C1 L77 - 228/234, .604/.609 112 cam, JBA shorty headers, Solo high-flow cats, X-pipe, Cherry Bomb single-chamber mufflers (Frankenstein exhaust), Roto-Fab CAI, CTS-V torque converter, 3.45 Camaro diff, G8 red/black seats/steering wheel
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elc32955
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Re: Need help with engine noise

Post by elc32955 »

Wow, you're a man of rapid action! Most people just start thinking about pulling an engine over 5 days, you've got parts on the bench. Not bad! Keep us posted on how things are going and which cam you end up using. My powertrain warranty is up in < 30 days, after that... hmmm.... :twisted:

Eric
System Manager and your tour guide for the day. 2015 Caprice w/LFX, former NC DPS staff car. Partial hybrid G8/SS/Camaro SS interior mods, SS MyLink radio upgrade, 2016 Camaro V6 rims, GMPP Malibu chrome exhaust tips, otherwise bone stock for now.
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