Pulling Sucks--2001 Suburban 3/4 ton--6.0

[tahitiansoul]

Supercharge it

 

[Craig Nedrow]

We have a 21.5 Grand Imagine, pulled with our 2018 GMC 6.2. Mileage is consistent 9, pulls good. The 6.0 is an awesome engine. Have it tuned, (I use HP tuners). Small cam, (230 @ .05) around .600 life, 107-110 LSA. I also love the 454, tows anything.

 

[Bextreme04]

We have a 21.5 Grand Imagine, pulled with our 2018 GMC 6.2. Mileage is consistent 9, pulls good. The 6.0 is an awesome engine. Have it tuned, (I use HP tuners). Small cam, (230 @ .05) around .600 life, 107-110 LSA. I also love the 454, tows anything.

I just finished assembling the 6.2 for our 2011 Suburban. It currently has the 5.3 and we pull a 6400lb Keystone Crossfire. I get about 6-8mpg currently and the 5.3 is generally just not happy(but I'm also getting garbage mileage unloaded so it's likely just a tired engine issue). I got the L9H 6.2 used and just pulled it apart and refreshed the heads and had it all cleaned up and inspected. New cam bearing, quick deglaze hone on the cylinders since they were still in-spec, and then reassembled with new bearings and rings. The only change from stock is a TSP stage 1 VVT cam which is 216/229 @.050, .600" lift, and 114 LSA and 107 ICL. It's got the limiter in the VVT gear to manually restrict the cam retard to ~30 degrees, and I'll have to do quite a bit more tuning with it being a VVT cam, but it should help produce a bunch more low end torque while still bumping the peak HP up over 500 at the crank @~6500RPM. Should be way better for towing all the way around. The 5.3 is only rated for 320hp@5500rpm and about the same torque stock.

 

[Keith Seymore]

Definitely something is wrong.

I've pulled my Haulmark enclosed (24 ft, approx 7500 lbs) all over the US, often with 1/2 ton GMT800 utilities with no issues.

K

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[GTX63]

Late posting to this thread, but I have some experience related to the OPs set up.
I have pulled RVs and equipment trailers up to and maybe past my tow rating on my current truck for 10 years. 6.0 with 4.10s. Living in Tn, I've been on steep grades, winds, heavy traffic more often than not. A dog would not be an accurate description of the drivetrain I have.
Yes, an exhaust restriction is the first thing I would look for. A 6.0 did not come from the factory unable to pull a camper thru a headwind on flat ground, and an aftermarket tune should not be considered a fix for the present underlying problem. I'd also tear down and inspect the camper brakes/bearing/spindles. Or hook up to something else and see if there is a difference pulling.
Trying to push exhaust thru a restriction makes everything work harder. Pulling an RV that is fighting back and making you drag it will cause the engine and tranny to run hot.

 

[OldBlueDually]

Well it is camping season! I parked the dumb thing over the winter and did not work on it, nor drive it. I worked on my Dually instead

I dreaded pulling the camper home, had my foot into it against a heavy head wind. Had her in 3rd gear and let it buck as you guys said--I no longer run the two/haul, it struggled against this wind! Luckily it is within 8 miles of home where I store the camper.

We camped this past weekend locally (30 miles away) and my drivers rear caliper hung up on me so at the campground I got that nice scent of hot metal. Driver side rear rim was nice & hot, so it's time to replace calipers/pads in back. Rotors look good. Doing that this weekend, and also replacing engine oil cooler lines--never been done and they look very wet. The drive itself for camping this past weekend, not bad either direction--3rd gear, no tow/haul, and 62mph is the sweet spot (rpm's good, engine running temp good, trans temp good)--but still, the reason I started this thread is because it's an effing pooch and really pisst me off last year.

Back to the engine: I will look at the exhaust, see if anything is plugged up/restricted by using the vacuum gauge method. I will yank plugs and check them also--Not sure if plugs or wires have ever been replaced. I've personally never changed them. I have been very lucky, and have had no engine codes indicating any O2 sensor issues.

I'll let you guys know how it all shakes out and see what happens. We have more camping trips planned, including one that takes about 6 hours one way...so I need this pig to work.

 

[Old Guy Bill]

When you’re loaded for a trip hit one of the CAT scales at a truck stop, it’s easy and will give you a true weight of your rig.