# Need Feedback on the 8.1 liter engine



## JCurtis (May 14, 2001)

I am currently looking at a 2001 GMC Sierra 2500HD with a 8.1 Liter engine.

Anyone have any experience with them good or bad?


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## long0 (Jul 11, 2002)

I've had two problems with mine. Same truck, 01' GMC 2500HD Reg Cab - 8.1L - Allison Auto

The oil pan is aluminum but they did not cast any steel into the pan to secure the drain plug. Instead, GM decided it was a good idea to heli-coil the drain plug. A couple of months ago, the heli-coil came out with the plug. - Bad Design

Power steering pump went out a couple weeks ago. Most likely due to the way I was driving the truck. Not really a big deal, it was covered by warranty, but the power booster for the brakes run off the power steering pump. - Another Bad Design IMO

Overall, the truck (and motor) have been great. You have to be careful about how much foot you put into if when pulling away from stop lights and such. Rear tires might get expensive quick. 

Gas is another story, it's always expensive. A couple of times I have been able to get 14 - 16 mpg, but most of the time it is around 9 - 11 mpg. On the good side, I have not gotten anything worse than 6 mpg, whether it was plowing or towing 15,000lbs, I always get at least 6mpg  

Let me know if I can answer anything else for you.

Andy


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## Shaper (Jan 9, 2003)

*GMC 8.1*

Back in November I traded my 2001 GMC 2500 HD 8.1 in for a 2003 GMC 2500HD Duramax.

Overall I liked the engine, it is very comparable to the Duramax as far as power goes ( plowing and regular driving). The Duramax is much better if you are going to be towing heavy loads. I tow a 36' fifth wheel that I use for work. The diesel can't be beat for towing purposes.
Fuel mileage is another downfall to the 8.1. You can expect 11-12 highway and 7-8 towing.I hear that the 6.0 mileage is close to the 8.1. If I had to choose between the 6.0 and 8.1 I would go with the 8.1, not just for the horsepower but for the fact you would have the allison tranny to go with it. The allison can't be beat!!
I did have a few problems with the 8.1. I had a push rod brake at 38,000 miles but was taken care of by GM. There was a TSB out for that problem with a certain batch of engines. The only other thing was that the cam sensor had to be replaced at 20,000 miles.


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## myo (Dec 2, 2002)

SHaper, do you have any pics of your duramax? I have one too and I agree that they can't be beat.


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## JCurtis (May 14, 2001)

*Thanks for the input....*

I am looking into a "new or newer" truck.

Seems that most of the dealers around me in CT have mostly 1/2 tons.

Massachusetts on the other hand has a couple of trucks that seem interesting. The hardest part of them being in Mass. is getting the time to get up there to look at them.

One of them is this 2001 GMC with the 8.1, the other is a brand new 2002 Chevy Dmax, and the third is a 2003 GMC Dmax. They are all the color I want (Black) just varying options and of course pricing.

Obviously the 2001 8.1 Liter is the least expensive, guess I better go talk to the boss and the bank (unfortunately they are one and the same person... my wife LOL  )


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## Foz (Mar 27, 2001)

Jeff;

I have 2 GMC 2500HD with 8.1 we use for plow trucks, both with Allison auto & have been very happy. Just purchased a Yukon XL with 8.1 for the wife, we took it to Atlantic City the first week & got around 13.3 MPG with me traveling at 75 - 80 MPH.

Like with any truck, dealer service is very important. Also have Dmax in my three dumps & have been happy with them also..but the extra $$ for the engine


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