8.1L Big Block Burning Oil ???

[Super Chevy]

Searching through this site (Which...I have found addictive ) I have seen a few posts with people complaining about the 8.1L engines burning oil. One person posted that their 8.1L engine burned one quart every 500 miles!

 

Now, I have a 2003 8.1L engine with a few thousand miles...I have not burn any detectable amount of oil...nor have any of my freinds that have 8.1L in their 2002 trucks.

 

Which leads me to these questions...

 

How many miles are on your truck?

How many miles do you go between oil changes?

What kind of oil do you use? (grade/brand/wt/dino/synth)

If you are burning oil...how much? (quart/miles)

Anyone have an oil burner and found a solution?

 

Just thought this has puzzled more people out there than just me

[ugeesta]

I added a quart around 3,000 miles. Now at 3,800, I havent noticed much drop in the oil level. The CSK sure sounds nice tho...

[HendyPhoto]

I have 20,000 miles, and I add 1/2 quart between oil changes (3500 miles), and thats just to be safe, it never drops below the normal level. I did add 1 full quart a few months ago because I was towing more than usual. Some trucks burn, some dont. I had a dodge dakota with the 5.2 small block that burned 2 1/2 quarts of oil every 3,000 miles. I expected more consumption from a big block, but I think the more you tow, the more it burns.

[raventai]

at 43K mine burns about a quart every 2,000 when it was new it burned one every 3,000. it has had mobil1 10-30 seince 1,500 miles changed every 3,00 until 20,00 and then by the oil-life system (about 5k)

 

 

the 454 that this motor is based on was also an oil burner, not a big problem IMHO

[racer]

here's one problem

High Oil Consumption (Replace Intake Manifold Bolts) #02-06-01-035 - (10/17/2002)

High Oil Consumption (Replace Intake Manifold Bolts)

2002 Chevrolet Avalanche

 

2001-2002 Chevrolet Silverado, Express, Suburban

 

2001-2002 GMC Sierra, Savana, Yukon XL

 

2001-2002 Chevrolet and GMC C6-7 Conventional Cab Medium Duty and B7 School Bus Models

 

with 8.1L Engine (VINs G, E -- RPO L18)

 

Condition

Some customers may comment about higher than expected oil consumption. Because this type of engine is used under various load conditions, the dealer should verify that the vehicle is using more than 0.946L (1 quart) of oil for every 379L (100 gallons) of fuel used.

 

Cause

Oil vapor pulled into combustion chamber through the intake manifold may cause this condition.

 

Correction

Replace all the intake manifold bolts. Replace one bolt at a time in sequence to keep the intake manifold from shifting.

[raventai]

Correction

Replace all the intake manifold bolts. Replace one bolt at a time in sequence to keep the intake manifold from shifting.

that is very interesting, I wonder why they say to replace the bolts and not just re-touque the current ones? are there new diffrent bolts? anybody got a part #

 

I am gonna have to go and find the torque and retouque those bolts on mine see if any are loose

[bummed-n-Md]

Last year I was a VERY vocal raiser of this issue. Probably the MOST VOCAL.

 

At first I was EXTREMELY unhappy (hence my handle). Most of my displeasure was the lack of support and 'openness' of the dealers. The first time I went to the dealer THEY said it was excessive (2.5 qts in 2000 miles) and if it did it again they would put me on a oil monitoring program. Well 2 weeks later, 2qts down in 2000 miles. This time I am told it is Normal and received no other explainations.

 

My truck (see sig) was consistantly going through 1 qt every 1200 miles. I could watch the oil level drop 1 hole on the dipstick every fillup.

 

At 18000, consumption dropped to 1/2 of that, 1 Qt every 2400.

 

at 23000 it dropped again and at 33000 it dropped once more.

 

I now have 35,850 in 16 months of driving. I go through about 1 qt every 4500 miles (which is also about how often I get the "change engine Oil' light on my dash. When the light comes on, I change the oil).

 

Once I figured out that this was a engine breakin issue (seating the rings etc), my concerns setttled down.

 

I have zero complaints now about the truck, although I am still very unhappy with the dealers.

 

bummed.

[422 SS]

I'm the guy with the 500 mile to the qt 8.1.I have 58,000 miles on the truck and I'm closing in on my 100th qt of top-off oil.I have a 2002 crewcab shortbeb 4x4 8.1 ally.I have had all the dealer remedies performed and still no improvement.I have used many different oils from 5w30 up to 20w50 mineral and synthetic it makes no difference.I change oil when the light comes on usually every 3800-4500 miles.Oil change intreval have nothing to do with it.My truck burns just as much on a fresh change as it does any other time.I burn a qt for every 2 1/2-3 tanks of gas (26 gal tank).The only time my truck has'nt burned oil is when driven on a long freeway only trip at high speed.Three 3500 round trips to S Florida at 80-85 mph and it burned less than half a qt each trip.Any other time it's like an alcoholic swilling cheap wine.On the positive side it does'nt affect the reliability of the vehicle or performance.IMO don't worry about it,my truck burned oil from day one and still does .If your does'nt it probably wo'nt.They just don't start burning out of nowhere.

[MarkD]

Correction

Replace all the intake manifold bolts. Replace one bolt at a time in sequence to keep the intake manifold from shifting.

that is very interesting, I wonder why they say to replace the bolts and not just re-touque the current ones? are there new diffrent bolts? anybody got a part #

 

I am gonna have to go and find the torque and retouque those bolts on mine see if any are loose

They are probably torque to fit bolts. GM is using a lot of those now.

[CMNTMXR81]

Torque to yield you mean.

 

What they do is stretch some upon torquing of them. Head bolts on LS1 and LS1 derivatives as well as some intake plenum bolts are this style.

 

I've got 20k on mine, and I'm in the same boat as Hendy. Sometimes it's down no more than a half quart between oil changes, sometimes it doesn't burn a drop. Also, I think some are finding out that when they are new and still breaking in, they are burning more than those of us with some miles on them.

 

BBC's consume oil!

[Hacksaw Hilliard]

This is the 2nd 8.1 in my truck; it was replaced @ 16K due to a persistant coolant leak. On both engines, the oil consumption was the same; about a quart every 3,000 miles. I read somewhere about a new PCV valve that GM came out with that reduced oil consumption in the 8.1. Anyone know about this?

[bcfitzsimons]

Hacksaw-I'd recheck that about the PCV valve. If I remember correctly (CMNT could clarify this) the 8.1L doesn't have a PCV valve.

 

Even in the big-block days of old, every big block burned oil. Too much bearing surface to coat, and too much hot metal in the block that doesn't get evenly cooled by the water jacket. It's just a fact of life.

 

The one thing you may want to check with all that oil usage is your spark plugs, though-the stock AC's in mine were fouled at 18K miles-and I mean seriously fouled-and I ended up replacing them.

 

Fitz.

[CMNTMXR81]

8.1's do not have PCV's. See the other info about replacing intake bolts.

[raventai]

found a longer version of that intake bolt tsb including part #, the bolts are 2.17 each at GMpartsdirect wish I had the figure also

 

http://www.motorhomemagazine.com/forums/in...OnePage/Yes.cfm

 

 

Here is something that might be useful:

 

High Oil Consumption (Replace Intake Manifold Bolts) #02-06-01-035 - (10/17/2002)

High Oil Consumption (Replace Intake Manifold Bolts)

2002 Chevrolet Avalanche

 

2001-2002 Chevrolet Silverado, Express, Suburban

 

2001-2002 GMC Sierra, Savana, Yukon XL

 

2001-2002 Chevrolet and GMC C6-7 Conventional Cab Medium Duty and B7 School Bus Models

 

with 8.1L Engine (VINs G, E -- RPO L18)

 

Condition

Some customers may comment about higher than expected oil consumption. Because this type of engine is used under various load conditions, the dealer should verify that the vehicle is using more than 0.946L (1 quart) of oil for every 379L (100 gallons) of fuel used.

 

Cause

Oil vapor pulled into combustion chamber through the intake manifold may cause this condition.

 

Correction

Replace all the intake manifold bolts. Replace one bolt at a time in sequence to keep the intake manifold from shifting.

 

 

Notice

Ensure the intake manifold does not shift as the intake manifold bolts are tightened in the proper sequence. Failure to follow the entire intake manifold bolt tightening sequence exactly may result in an oil leak and serious engine damage.

 

 

In the order shown below, remove each bolt and replace with a new bolt. Insert the new bolt and tighten to 5 N·m (44 lb in). Then move to the next bolt in sequence until all bolts have been replaced.

 

 

 

After all of the bolts have been replaced, tighten each bolt in sequence to 8 N·m (71 lb in).

Tighten all bolts in sequence to a final torque of 12 N·m (106 lb in).

Parts Information

Part Number          12561518

Description           Bolt, Intake Manifold

Qty                        10

 

 

 

 

 

 

Parts are currently available from GMSPO.

 

Warranty Information

For vehicles repaired under warranty, use:

 

Labor Operation     J0290

Description            Bolts, Intake Manifold - Tighten or Replace

Models                   C/K, C6-7, B7                        G Van

Labor Time              0.7 hr                                  1.5 hrs

 

 

 

 

 

 

 

 

 

 

 

 

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

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[THE BIGPUNN]

i have 2200 miles in my 03 8.1, im down about 1/3 quart of oil. im not topping off...figure i'll wait and put synthetic in at my first oil change. where i work we have a fleet of cars some chevy, ford and dodge and all seem to burn more oil than normal the first few thousand miles. before i bought the 8.1 i did research and am not suprised about the oil usage or mpg. i currently monitor the oil usage and everything appears normal. plus every car ive owned usually took a quart in between oil changes. these fleet cars at my job sometimes need two quarts in between oil changes.