intake gaskets 2001 GMC K3500 8.1L

[Diamondpilot]

I have always like the 8.1L motor but not I am having second thoughts. Do all them burn oil like this? Many boats have the 8.1L in them making 375HP and they also have a HO version making 425HP.

I know it just may be my experience but every GM product but one that I have owned has used oil like crazy, a 1996 Saturn. Wait, make that two, my Dmax did not use any oil either, but the GMC 3500 7.4L, Cadillac Northstar, S-10 Blazzer 4.3L, and my last Saturn all used no less than 2 qts between oil changes with the exception of that Caddy that only used 1 qt. None leaked oil, just burnt it. All these vehicles suffered catalytic convert and oxygen sensor issues that I am sure were due to oil consumption. I have also had multiple boats with 305, 350, and 454 GM based engines and they use a little oil but more like a 1/2 qt per season. They only get used on a average 75 hours per year and I run a much heavier oil. Usually 15W40 diesel rated oil or 20W50 marine oil. Some like strait 40W oil also.

We have owned vehicles from Ford, Honda, Toyota, Nissan, Chrysler, Volvo, Mitsubishi, Suzuki, Infinity, Lexus, ect and not one has ever needed a drop of oil added between changes.

As for the crank case vent could you just drill and tap the oil fill cap and the drill and tap the intake plenum aft of the Mass Air Flow Sensor and run a piece of fuel hose between the two????

Chris

 

[wmonroe]

I only know two people that own 8.1 chevys, both are 2006 2500's, one belongs to my neighbor and the other a good friend of mine. My neighbors truck uses about a quart to a quart and a half per 1000 miles, he never changes his oil just changes his filter every 5000 miles. My friends truck only uses about 2 quarts per 4000 miles. My friend is a die hard chevy guy and loves his truck and would buy another tomorrow, but my neighbor just wants a reliable truck and is disgusted that several chevy dealers tell him nothing is wrong with it, he says he won't buy another chevy truck.

 

[FlaDon]

I have always like the 8.1L motor but not I am having second thoughts. Do all them burn oil like this? Many boats have the 8.1L in them making 375HP and they also have a HO version making 425HP.

I know it just may be my experience but every GM product but one that I have owned has used oil like crazy, a 1996 Saturn. Wait, make that two, my Dmax did not use any oil either, but the GMC 3500 7.4L, Cadillac Northstar, S-10 Blazzer 4.3L, and my last Saturn all used no less than 2 qts between oil changes with the exception of that Caddy that only used 1 qt. None leaked oil, just burnt it. All these vehicles suffered catalytic convert and oxygen sensor issues that I am sure were due to oil consumption. I have also had multiple boats with 305, 350, and 454 GM based engines and they use a little oil but more like a 1/2 qt per season. They only get used on a average 75 hours per year and I run a much heavier oil. Usually 15W40 diesel rated oil or 20W50 marine oil. Some like strait 40W oil also.

We have owned vehicles from Ford, Honda, Toyota, Nissan, Chrysler, Volvo, Mitsubishi, Suzuki, Infinity, Lexus, ect and not one has ever needed a drop of oil added between changes.

As for the crank case vent could you just drill and tap the oil fill cap and the drill and tap the intake plenum aft of the Mass Air Flow Sensor and run a piece of fuel hose between the two????

Chris

It is common for them. GM says nothing is wrong until you burn 1 qt per 800 or less miles.

 

[Diamondpilot]

It is common for them. GM says nothing is wrong until you burn 1 qt per 800 or less miles.

That is the same thing they told us when we bought our last Saturn. It burnt a qt per 800 miles and they said 1 qt per 600 miles and they would rebuild it.

What they did was take it in and top it off and note the mileage. I then took it back and after 600 miles they took a measurement on how much it dropped. What the tech suggested I do was buy a formula made by GM called Piston Ring Cleaner or something like that. Remove all the plugs and put a wrench on it level out all 4 pistons in the cylinders. Pour this stuff in via the plug openings and then add 3 oz of Coke per cylinder. That made me nervous. Also add 3 oz of diesel fuel and let it sit for 1 hour. Next take a turkey baster with a piece of hose and suck out as much as you can. Turn the engine over with the plugs out to blow it out then put the plugs back in and start it. Let it warm up then drain the oil and replace with Mobil 1 to clean it out for 500 miles then back to the regular oil. Mobil 1 due to its high detergent rate.

I was afraid to try it but they said the reason GM products burn oil is the rings get carbon build up. This procedure will free them up.

I just switched from 5W30 to 10W40 at around 75,000 miles and the oil burn rate went to 1 qt per 1,200 miles or every 3 fill ups add a qt. It stayed that way until I sold it with 128,000 miles to my insurance man for his daughter who totaled it in less than 2 months. It was actually a good little car. Everything worked but it did need nickle and dime items about every 3 months or so like wiper motor, ignition switch, neutral safety switch 3 times, ball joints, sunroof motor, window regulator, ect. It never got worse than 33 mpg out of a tank of fuel.

Chris

 

[Renze]

I was afraid to try it but they said the reason GM products burn oil is the rings get carbon build up. This procedure will free them up.

DOT4 brake fluid works best to free piston rings. Used it on tractors, Merc diesels, and the former leader of our company (who uses our shop to wrench on his sons '71 Merc) freed some piston rings and got good compression on that motor, after letting it soak in brake fluid for 2 weeks.