The Monstrous Vortec 8100 496 8.1L Big Block Engine of the 2000's

Thank you for making this enjoyable video. Bought a used 2004 2500HD CC long bed LT with the 8.1L in 2005 with 19,500 miles. Was like new and paid $22,500 for it. The truck just turned 300k miles and has proven to be one of the top purchases I’ve made. Repairs: 1 coil pack, 4 sets of plugs, TPS replacement, 1 alternator, 1 master cylinder, all new brake lines, driveshaft carrier bearing, Windshield washer pump, new AC compressor and I’ve had various electrical issues (none severe). Normal brake maintenance etc.. Have friends that have purchased 4 or more trucks in the time I’ve owned the 2500HD 8.1L and have not once felt the need to shop for anything else. I believe, in several ways, buying a new truck would be a downgrade.

My 2004 Suburban tows a 12 ft cargo trailer all over the USA. 15 mpg on a good day. 250,000 miles, zero problems. If it had more gears it would get even better mileage.

Love these engines. My 2002 burban 2500. Pulls like a champ starts every time. 10500lbs camper hooked up. Never misses a beat. 4l80e holds the power just just fine nice crisp shifts. 201000 and climbing. It’s a shame when something this reliable comes to an end.

I bought a 2001 2500HD new from the dealer with the 8.1. It is still my daily driver and my work horse @ 326.000 miles. I had to put a cam sensor in at 100,000 miles but no other issues. The truck itself has been beat to hell and back but keeps going. I have a couple of small leaks from oil lines and it burns a TINY bit of oil since day 1. I expect to have this truck and engine for at least another 250,000 miles. Yes, it has the Allison and I love that thing too.

@ 8:20 - 8:25 = (Lost Foam Casting ). I have this Vortec 8.1L in my 2000 National Surf Side . It's perfect for my application . It's the next best thing to a Diesel pusher . Thanks for the Great post .

Got a 02 avalanche with 8.1 bought it with 96k now has 286k has not skipped a bit beat and still pulls like hell I love it.

I have the 2001, 270,000 and it is still as strong as it ever was , Love the set up of the Trans and motor , Headers and a Big K_N Filter ,

Two comments about problems I’ve experienced with this engine… 1st glad you showed the back of the block. At about 90K miles I had the crank sensor fail and leave me in a Walmart parking lot. It’s not serviceable from under the hood, you have to reach up from underneath, around the bell housing and try to pull it out. In my 40+ years as a shade tree mechanic, I have never come this close to curling up and crying uncontrollably. I ended up having the truck towed to a local dealership for repair. At this point there were just wires coming out of the hole. When I asked the mechanic how he did it, he said “plenty of thread penetrating oil and a curved set of needle nose pliers”. A very frustrating and expensive learning experience. Second on the list, on my truck the exhaust pipe crosses behind the oil pan by just a few inches. Not a problem unless someone tries to use an impact wrench to remove/install the oil drain plug. The hole has been stripped for a number of years now and I can’t get any of the typical oil change businesses to change my oil because they don’t want to deal with a vehicle with a temporary plug in the pan. It’s a bit of an irritation at times. Other than these items, the engine is still running strong after 20+ years. Not too shabby

I really think you missed your calling with this vid. Great explanation and detail, it's like a show aired on the history channel for the 8100!! I rarely turn that bell icon on for any channel but I will for this one!

I have that engine in a 2003 motorhome, runs great and pulls hard.

I have an 2002 chevy crew cab dually 3500 with this motor. Bought it 2 yrs old. I still have it. Runs very well...no issues. It does consume some oil but nothing excessive or ridiculous. Plenty of power. I've pulled some heavy trailers and it's done well. It does use gas. 10 miles per gallon in city driving is the norm. Very dependable. Always starts and idles beautifully. Very quite and smooth.

Awesome overview, great detail! I've got an 8.1 extended cab dually, and it pulls awesome. My only complaint is with the Torque Management system, which I intend to tune off shortly. The combo of this capable, simple engine in front of an Allison transmission makes it impossible to justify the cost of a new truck.

Great video and yes very few people know about the 8100 Vortec. In my opinion and experience with these 8100's, they are the best ever made. I own a few 8100's and 7400's (all GMC duallies, Suburbans & Yukon XL) and my daily driver is a 2002 GMC Extended Cab dually 8.1/Allison with 4x4 on the floor and I'm close to 800k miles. The motor, transmission and axles have never been rebuilt or replaced. The only major part replaced has been the transfercase about 3 times but other than that, just regular maintance and minor parts it is needing that I have done myself. She is my baby and I take really good care of her always. Many people don't believe me about the mileage (especially diesel guys) and this truck is used to work hard and doesn't give up at all. I have always pulled with it all over Texas(my home) and a few more states and have done alot of traveling in it since the first day I bought her(15 years ago with 32k miles from the first owner like brand new😍) and she still pulls hard like a mean beast. I'm still searching for more to buy no matter the distance.lol Well I can go on and on but I really enjoyed your video and all the info is great and I'm looking forward to more videos and yes, I am a GM Big Block guy too👍Thats all I own since I driv

I've had my 02 ccsb Chevy HD with the 8.1 for 4 years now. I still absolutely love it. It has a custom tune, set up for 89 octane and gets 11 mpg all around average. With 4:11 gears and 285 tires I can manage almost 12 mpg empty on the freeway under 75mph. I pull several trailers but it's biggest impact is my 20' steel frame cargo trailer. It's a foot overheight and bucks wind like crazy. The truck pulls it easy but I average 7 mpg with that no matter how much weight is in the trailer. As far as oil consumption. I've found old school conventional 10-30 is best. I use maybe a quart between oil change. I ran a synthetic and a blend a couple times to try but experienced poor results using as much as 3 quarts between changes to keep the ol girl full and happy. Thanks for your video.

I just bought my 1st 8.1 in a 2500 HD GMC Sierra and I fell in love on the test drive. Amazing how quiet it is and how smooth she rides. I’m the 3rd owner. Last guy had it for 3 years and an old man had it from the showroom floor before that and well cared for the whole truck.

i can speak personally for this engine. i had one in a 2009 GMC c7500 and hauled GCWR of over 30k daily. had the 6speed manual trans and was geared very low. this engine spent most of its life at redline. i drove this truck with 75k on the clock for 3 years including a trip from St. Louis mo. to Fresno California. that's 4 days driving almost 12hr days and it topped out at 65 so it was pegged the entire time. the truck/engine never complained. stayed cool and kept running until we retired it at 80k and i was given a 2021 f750 with the 6.7, wish i still had that old gmc lol.

Bought my 2002 2500hd Silverado brand new. Now has 201,000 miles. Contiplating if I should do the timing chain. Right now truck is down for a whole new suspension. Almost done. Did a solid axle swap using 1979 Ford Dana 60 kingpin. 10 inch lift with 40's. As far as problems I have had: Crankshaft sensor went at around 38,000 miles. Common problem with these. Air intake manifold leak throwing p0101 code. I actually drove on it like this for 8yrs. CEL would only come on during hard acceleration. I had a exhaust manifold bolt break off in the head due to heater core hose dripping on it. Was able to repair it with a heli coil. Still holding up after 7yrs. Oil pan gasket developed a leak. Replaced. But after doing the solid axle swap, if it leaks again it will be a breeze to do now. Camshaft sensor went out. Engine would crank and crank until it started. Not too bad to fix this.

great video more on the 8.1 please!!

I have a 2003 2500hd, 8.1 .130,000 miles.clean as f*ck. Good truck. Pulls great.love tha Allison.

THANK YOU FOR THE LOW DOWN ON THE MOTOR / VERY HELPFUL / I LEARNED A LOT THANK YOU