GM L87 V8 Engine Investigation NHTSA

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HEMIMANN

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Treburkulosis

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GM has had issues with the LS motors for several years now. This is nothing new. They like Ford did back in the 90s and early 00s fell behind to GM. GM has fallen behind to Ford. The Coyote engine is a superior engine not only for hot rodding, but for dependability. We wont even get into the Hemi tick. Toyota at least owned there’s. We will see what happens here. Did Stellants ever own up to the Hemi misdesign?
 

Treburkulosis

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To add to this and from a GM standpoint my grandfather bought a new 2015 Silverado 5.3 and yes at 75k his was on the verge of going out. We are sticklers on maintaining our vehicles. He caught his just in time. They had to rebuild the entire top end on his dime, but the guys that own the shop we have known for many many years. They at one point before buying this shop ran both the service and parts department at a local Chevy dealership. What we were told was is yes the cutting down the cylinders to save on fuel economy can hurt the engine, but only when 87 octane is ran. His says recommended 89 octane. The Rams were the same way if I remember correctly. Not saying that you couldn’t get away with it, Dodge just allowed you the option to turn it off. GM you needed to physically turn it off in the computer so most people wouldn’t mess with it. Thus the issues. If you really think about it how many people left their MDS on with the Ram ran 87 octane and took out the top end? It would be an interesting poll to see the numbers on.
 

White six four

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His says recommended 89 octane.
His owners manual states that? Or is that what someone said? The 501 page owners manual for our 15 suburban with the 5.3 just says to use 87 or higher octane. No recommendation or anything like most Rams owners manuals say.
 

Treburkulosis

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His owners manual states that? Or is that what someone said? The 501 page owners manual for our 15 suburban with the 5.3 just says to use 87 or higher octane. No recommendation or anything like most Rams owners manuals say.
His says it in the gas door. Same with my 12 ram it was suggested to run it. Didn’t mean that you had to run it, but clearly there was a reason.
 

ramffml

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If you really think about it how many people left their MDS on with the Ram ran 87 octane and took out the top end? It would be an interesting poll to see the numbers on.

That's an interesting theory, combination of low octane while using MDS. Just trying to think it through, how would that be a problem? MDS is only active when the engine is "basically idling", so not much demands for power, I would think that at that point the low octane gas wouldn't be a problem? I would sooner think low octane gas during high power use (2000+ rpms).
 

Wild one

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To add to this and from a GM standpoint my grandfather bought a new 2015 Silverado 5.3 and yes at 75k his was on the verge of going out. We are sticklers on maintaining our vehicles. He caught his just in time. They had to rebuild the entire top end on his dime, but the guys that own the shop we have known for many many years. They at one point before buying this shop ran both the service and parts department at a local Chevy dealership. What we were told was is yes the cutting down the cylinders to save on fuel economy can hurt the engine, but only when 87 octane is ran. His says recommended 89 octane. The Rams were the same way if I remember correctly. Not saying that you couldn’t get away with it, Dodge just allowed you the option to turn it off. GM you needed to physically turn it off in the computer so most people wouldn’t mess with it. Thus the issues. If you really think about it how many people left their MDS on with the Ram ran 87 octane and took out the top end? It would be an interesting poll to see the numbers on.
Never heard that one before. Go into more detail on what you mean by rebuilding the top end,as that usually means the pistons are still okay,and they'd be the only things that the lower octane fuel would affect.I'm guessing they rebuilt the heads with new guides and valves,but that's not usually from lower octane fuel
 

Treburkulosis

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Never heard that one before. Go into more detail on what you mean by rebuilding the top end,as that usually means the pistons are still okay,and they'd be the only things that the lower octane fuel would affect.I'm guessing they rebuilt the heads with new guides and valves,but that's not usually from lower octane fuel
Im trying to remember he’s almost 90 and I was talking to him on the phone. Heads, lifters, the cam some how survived. They replaced the injectors. Cleaned the intake tb etc and then they deleted the AFM. Those engines like dodge are known for doing that. Just like Dodge in theory it should have been a great idea, but in the real world it wasn’t. You don’t really ever hear about any LS engines pre AFM having these issues. They all have their major issues. Ford has the cam phaser problems. When they started making them hit certain MPG and certain emission standards that is when you started seeing the issues with the big 3.
 

Wild one

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Im trying to remember he’s almost 90 and I was talking to him on the phone. Heads, lifters, the cam some how survived. They replaced the injectors. Cleaned the intake tb etc and then they deleted the AFM. Those engines like dodge are known for doing that. Just like Dodge in theory it should have been a great idea, but in the real world it wasn’t. You don’t really ever hear about any LS engines pre AFM having these issues. They all have their major issues. Ford has the cam phaser problems. When they started making them hit certain MPG and certain emission standards that is when you started seeing the issues with the big 3.
Okay i could see that as alot of stations don't have fresh fuel in the tanks,and if he was using 87 octane from a low volumn station or from a low quality gas provider,then i could see injector problems causing those issues,but that's probably more from the quality of the 87,then the actual fact it was 87,as a better quality 87 probably wouldn't have the same issues
 
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HEMIMANN

HEMIMANN

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If not running Top Tier and having poor injector spray pattern from deposit buildup would do it too. You know how cheap and short-sighted the general public is. They won't seek out, nor spend another 3 cents per gallon of gasoline for top tier quantity detergent additives. For their $70,000 truck.
 

Treburkulosis

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Im spending top tier on my Flex and it has gotten sluggish lately. It’s all I have ran in it since 12k miles. Air filter is good so thats really the only thing you would think that would be causing sluggishness at 28k.
 

NCRaineman

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Im spending top tier on my Flex and it has gotten sluggish lately. It’s all I have ran in it since 12k miles. Air filter is good so thats really the only thing you would think that would be causing sluggishness at 28k.
Have you taken your Flex out and done the old "Italian tune-up"? The computers on modern cars learn as you drive so if you dont flog it at least somewhat regularly they'll get into granny mode and not want to go like they should.

I deal with that occasionally on our Ram because my wife is the primary operator and drives very conservatively thanks to her years as a paratransit driver.
 

Treburkulosis

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Have you taken your Flex out and done the old "Italian tune-up"? The computers on modern cars learn as you drive so if you dont flog it at least somewhat regularly they'll get into granny mode and not want to go like they should.

I deal with that occasionally on our Ram because my wife is the primary operator and drives very conservatively thanks to her years as a paratransit driver.
When I first got it, It had been owned by an older women. It had done a lot of sitting in 4 years she owned it. It wouldn’t get out of its own way. I switched the fluids over to synthetic, started running super, and put in a dry high flow filter. I would say 95% of the time the pedal is on the floor, its spinning at a red light, or I am cornering the big box through some pretty sweet corners on my way to beat the slow and confused at the next roundabout. Same way on the hwy. It rarely sees less than 80 at any time. I do run it in sport mode all the time. I am honestly wondering if it isn’t gas. I fill up at 1 station every time, but Sunday I had to go elsewhere. I drove it most of the day yesterday and it ran fine.
 

NCRaineman

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I am honestly wondering if it isn’t gas. I fill up at 1 station every time, but Sunday I had to go elsewhere. I drove it most of the day yesterday and it ran fine.
Certainly possible, speaking from my own recent experience with some bad gas from a local station. Fortunately we always put 89 in the truck, which is a mix of regular and premium. I don't believe the truck would have run at all on whatever that station was selling out of the regular tank.
 
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