2011 silverado 4.8 thoughts

[HyundaiAbuser]

My parents just purchased a 2011 silverado 4.8 to pull their 2 horse trailer. As stated it has the 4.8 engine (no active fuel management bs to the extent of my knowledge) and what was an unlabled 4 speed (on the listing at least). My questions are is this 4 speed a variant of the 4l60e, if not then what exactly is it and what things should we look out for about these trucks by way of problems?
It only had 74k miles on it when purchased.

 

[GMguy84]

Should be a 4L60E, But not sure if the 4.8's got those 6L80E's in 2011 ???

I have a 2008 Silverado 4.8 4L60E crew cab with 200K miles as my work truck and power and acceleration SUCKS !! My heavier 5.3 suburban would outrun it. It will be a DOG pulling a 2 horse trailer

The 5.3 or even more the 6.0 would have been suited better for their needs

I would tell them to keep a high quality synthetic oil in it. Camshaft and lifter failures are #1 issue on these rigs. Luckily the 4.8's dont have the AFM
(Active fuel 4/8cyl mode management) garbage on them.


Below I posted a video from 1Aauto on common issues with the GMT900 trucks

Dash board falling apart, Engine mounts, door handles, oil pressure sensor,

For me its been:
Horrific Dash cracks
power door lock actuators
Outer door handles

Dave

 

[OilMagnate]

74K on a 4.8L? Yep they picked well. No AFM to worry about. It will handle the trailer just fine, assuming the two horses aren't overweight Clydesdales and they don't have 6 people in the cab. We've pulled 2 large bulls in a cattle trailer long distance with a poorly maintained 1998 Sierra with a 4.3L and a terrible transmission. They'll be fine.

Sure, a 6.0L would be better, but all the fuel wasted when not towing isn't really worth it.

 

[tblt44]

My old 4.8 gmc had the tow package with 3.73 gears. It could pull better than my avalanche 4x4. The 4.8 had plenty of power
All depends on the gears. The codes in the glove box will tell you your gearing

 

[levi]

My parents just purchased a 2011 silverado 4.8 to pull their 2 horse trailer.

I have a 2007 Silverado Classic crew cab with the 4.8 and 4L60e, 120K. Standard gears. Acceleration is lacking severely. Engine just doesn't respond to the gas peddle unless you practically floor it. Drives me nuts.

Think it is more of a programming function than total lack of power.

 

[supton]

4L60's can last a long time--and if not, they are cheap to rebuild & upgrade. Not sure I'd worry about it, other than making sure it has fresh fluid and a good trans cooler.

Does this have a tow package? What rear end ratio? Both should be an RPO code in the glovebox (?) (maybe they moved the build sheet).

4.8 might be a bit down on power. If acceleration is lacking it may be worthwhile swapping rear gears (hopefully it's a 2WD) for something deeper. That said, it's a 4.8L, you likely will want to leave it out of overdrive while towing in general, and I'd expect it to drop down to 2nd on any good hill.

AFAIK the 4.8 in the Silverado never got the 6L80. The 4.3 did not either, not until the engine was overhauled.

 

[MacManus99]

I agree with the above. The 4.8 is a workhorse. Maybe a work pony. Still, I would change all the fluids out and expect a long life out of that vehicle.

It seems everyone thinks they need all kinds of power... especially when towing. Power is just a convenience, and the absolute last thing you should worry about when pulling a trailer. You would be surprised at how quickly you adapt to an anemic engine.

 

[Chris142]

Is the loaded trailer within the weight the door sticker says it can pull?

 

[A_A_G]

Slap an LSA supercharger on it and you won’t have any problems with towing.

 

[Bud_One]

We had three 2011 1/2 Ton Ext Cab GMC Sierras for shop trucks.
All had 4.8 V8s and 4L60Es . All three had over 240k when we sold them. Were used like 3/4 trucks , all our vans/trucks carry inventory, tools and heavy parts.
We replaced shocks and brakes the most . One with the most mileage was 280k and it's transmission lost 3rd/4th gear. Would shift first to second fine but would rev and not accelerate when shifting to third.
We sold it to an individual who replaced the trans with a junkyard unit and has close to 400k on it now.
They're not powerhouses by any means , but they got the job done and would have been with us still if we had used them like 1/2 tons .

 

[dareo]

The 4.8 is a shorter stroke 6.0, so if you are patient in accelerating and take care of it, it could last pretty much forever.

 

[OVERKILL]

It will be slower than the 2nd coming, but should hold up just fine assuming the trans stays together, but as others have noted, they are cheap to replace.

 

[GMguy84]

I did do this upgrade to my 4.8 last night. BEST $55 I ever spent on a engine MOD lol


Dave

 

[GMguy84]

4L60's can last a long time--and if not, they are cheap to rebuild & upgrade. Not sure I'd worry about it, other than making sure it has fresh fluid and a good trans cooler.

Does this have a tow package? What rear end ratio? Both should be an RPO code in the glovebox (?) (maybe they moved the build sheet).

4.8 might be a bit down on power. If acceleration is lacking it may be worthwhile swapping rear gears (hopefully it's a 2WD) for something deeper. That said, it's a 4.8L, you likely will want to leave it out of overdrive while towing in general, and I'd expect it to drop down to 2nd on any good hill.

AFAIK the 4.8 in the Silverado never got the 6L80. The 4.3 did not either, not until the engine was overhauled.

Mine is a 3:23 rear drums(SLOW DOG......woof woof) if I decide to keep this Silverado for a longer time I might upgrade to 3:73 posi rear disc RPO GT4/ G80

My '01 suburban has factory tow pkg. So it has the GT4/G80 combo 3:73 Posi rear disc and the take off speed is GREAT !!

Dave

 

[OVERKILL]

I did do this upgrade to my 4.8 last night. BEST $55 I ever spent on a engine MOD lol


Dave

View attachment 30032

You made it louder? The 4.8L definitely wouldn't be starving for air with the stock intake and airbox.

 

[GMguy84]

You made it louder? The 4.8L definitely wouldn't be starving for air with the stock intake and airbox.

??? Well It did improve acceleration/throttle response

Trust me I could REALLLLLLLLLLLLLLLLLLLLLLYYYYYYYY tell the difference in this truck last night right after the CAI was installed

Dave

 

[HyundaiAbuser]

I'm pretty sure it is a 3:23 gear ratio. They're only pulling the trailer about 4 miles at a time most of the time and about once a week at that. The rest of its life will be spend on the highway on a 45 minute commute. But its nice to know that they can last, I've always had a strong distaste for GM AFM engines. And yes the trailer with the horse in it is below tow ratings.

 

[OVERKILL]

??? Well It did improve acceleration/throttle response

Trust me I could REALLLLLLLLLLLLLLLLLLLLLLYYYYYYYY tell the difference in this truck last night right after the CAI was installed

Dave

I have a hard time believing that unless your air filter was plugged solid. The stock power figures are measured with the factory engine dressing, exhaust and intake, typically the only engines that benefit from a modified intake are ones that are... modified, and thus consume more air than stock and even then, that would only be of benefit at WOT.

 

[GMguy84]

I have a hard time believing that unless your air filter was plugged solid. The stock power figures are measured with the factory engine dressing, exhaust and intake, typically the only engines that benefit from a modified intake are ones that are... modified, and thus consume more air than stock and even then, that would only be of benefit at WOT.

1000% true I could REALLY tell with difference in performance after the CAI kit was installed. This is my work truck I drive it 100 miles a day or so around Dallas

Have been having acceleration/throttle response "hard pedal" issue since I bought it but this upgrade really has improved all those issues


Possible the factory AI was clogged or defective ???

Dave

 

[OVERKILL]

1000% true I could REALLY tell with difference in performance after the CAI kit was installed. This is my work truck I drive it 100 miles a day or so around Dallas

Have been having acceleration/throttle response "hard pedal" issue since I bought it but this upgrade really has improved all those issues


Possible the factory AI was clogged or defective ???

Dave

When was the last time you had changed the air filter?