Oil Usage-Big Block-Long Term

BrokenBoots · March 9, 2003

For anyone who has 15,20,25 K on their 8.1L, how has the oil usage fared?

At 1700 miles, I had to add 3/4 of a quart.

What is the long term prognosis?

t-76y2kss · March 9, 2003

I have kept a journal on my 8.1 since low oil light came on at 1800 miles.Im at 46,000 now truck has required 39 qts between changes to stay close to full.I change at 4000-5000 mile intravels usual burn a qt ever 800-900 miles in town on 3 long trips empty 3000 miles less than a qt per trip.I only add up to 4000 after that I just change it.I recommend you keep a good paper trail contact a good lemon law attorney,I did

mhraracing · March 10, 2003

Is excessive oil consumption common in these 8.1 's ? - On my post below ... all you guys talked me into the 8.1 - But if this is a common occurance please let me know!

For what its worth my 2002 6.0 - doesnt burn a drop of oil ???

Thanks

racer · March 10, 2003

here's part of a tsb about the 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.

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.

Gunruner · March 10, 2003

Is this type of high oil consumption common in the 8.1L? If this is normal, why would anyone opt for the big block? I have the 6.0L and I haven't used a drop as the above poster with the same motor stated. Only engine I ever had that was new that used oil like the 8.1L was a 360V8 Chrysler that used 35 qt. in 5 months. That was when Chrysler had to buy it back. I think I'm glad I went with the 6.0L. Good luck guys.

bummed-n-Md · March 10, 2003

If you look back to post about a year ago, I posted very heavily about my disatifaction with oil consumption in the 8.1L. I was going through 1 qt every 1000 to 1200 miles.

I was pi$$ed because I could get no info from the dealers.

In 10 months of driving, I now have 25000 miles on the truck. I change my oil every time the 'Change Oil light' comes on (on avg about 4500 miles).

I check my oil level at EVERY fuel fill up.

I am very happy to report that my oil consumption is now averaging about 1 qt per 4500 to 5000 miles. This is what I would consider acceptable usage. :thumb:

At just about 18000, like the computer 'threw a switch', my consumption went from 1/4 qt at each fill up to 1/4 every other fill up. At about 23000, it again 'switched' to 1/4 qt about evrey 4 fill ups. Because I check and write down my oil dip stick reading at every fill up, this change over was very noticeable.

All I can say is, it is probably an engine break-in issue, waiting for the rings etc to seat. I would have been a whole lot more please with GM if they were up front about this instead of just saying 'its normal' with NO explanation.

(hence my handle, for a while I was really bummed out about this oil issue.)

bummed

CMNTMXR81 · March 10, 2003

Do a search on this already!!! There are numerous posts pertaining to BBC oil consumption.

I don't care what any of you say (or have to complain to GM about), BIG BLOCK CHEVY V8's CONSUME OIL!!! Period, Nada, End of Story!

Since the first Rat motor popped out of Chevy's little hands, BBC's have consumed oil! A BBC that doesn't consume oil has a problem somewhere!

BIG BLOCK CHEVY'S CONSUME OIL!!!

BIG BLOCK cHEVY'S CONSUME OIL!!!

The reason this is NEW to everyone out there is because up till now, a BBC V8 was relegated to commercial use mostly on 1 ton work trucks (yes, I know 3/4 tons came with it too), Motorhomes, Medium Duty trucks, and in all out drag race applications.

Now GM has brought it's new BBC down and put it into more consumers hands. Those are the same consumers that generally cringe at the idea of ever popping the hood and expect to have Toyota Camry like everyday qaulity out of what still is essentially...a work implement that is meant to work hard (gee, what a concept). When you work something hard, it tends to consume things a little faster...oil included.

Mine now has 17k on the clock and uses about a quart of oil between changes. Que sara, sara! It uses oil! So what! A quart of Valvoline once between changes doesn't break the bank at a whole whopping $.99 a quart.

I'm sorry I sound so sarcastic to antagonistic but anyone who knows BBC's, knows they consume oil. Kinda like Harley's drip it, BBC's consume it! It's part of their personality. Deal with it or trade your truck in for a Tundra.

bummed-n-Md · March 10, 2003

CMX,

I am not trying to start a war here, but the concerns I posted last year were that while you are going through 1 qt between oil changes, I was going through 3. I agree that some oil consumption in ALL engines is normal, but not half the capacity between changes. This is what I believe others are also a little shocked at. If there is an engine break-in period on these rigs, and GM is bringing them down into the 'consumer market', they should at least put something in the owners manuals about it AND above all tell the dealerships, both sales and mainatenance, to be up front about it. Proper communications would alleviate alot of the 'heartburn' you hear on this forum about this issue.

As I stated above, now that my oil usage is down to a very respectable 1qt between changes (and appears to be getting even better), I am no longer upset about the vehicle. I really enjoy everything about it. I only wish 'GM' would have been more forth coming instead of voicing a boiler plate 'its normal' with no other explaination. I learned more on this forum about the 8.1 (a lot of it from your posts) than I did talking to a number of mechanics at the dealerships.

enough of that.......

I would ask of you to do me a favor,

Now that you are close to 18K, and I'm not sure how often you check the dip stick, but check it during the next couple of fill-ups. Then continue checking it after 18K. I am curious if a 'switch' will happen on others they way it did mine. As I said it was noticeable and obvious (especially if you check the oil regularly) . It may have been just a 'happy' coincidence, but both times it was sudden and unexpected.

bummed. (no longer)

BrokenBoots · March 10, 2003

That is what I wanted to know....The long term results.

I read about the oil usage issue last year and STILL bought one a few weeks ago.

Thanks for the update.

CMNTMXR81 · March 10, 2003

All engines have a "window of legitimate oil usage/consumption" Some do use that window but most don't. This is on any motor from any manufacturer be it GM, ford or Mopar domestically to any foreign manufacturers. Engine's use oil Period. Some more than others. Many less if at all. However, GM readily tells you that their engines "could use" roughly around a quart of oil, whether it be a 2.2L 4 cyl in a Cavalier or a 8.1L Big Block V8. Chances are that the bigger motor will consume much more. Any properly running engine should! Now if it's burning a quart of oil just pulling out of your driveway, that's a whole different story! (I just didn't want others jumping over me about my last comment that a properly running engine will consume oil)

Once again, when and if you find a Big Block Chevy that DOESN'T consume oil, I would tell GM because they may want it to tear apart and find out WHY it wasn't consuming oil. Big Block motors consume oil, plain and simple. you can check it on a daily basis for all it matters, but it'll still use it.

Also, how scientifically accurate are your readings? You state you check it at each fill up (which would be near impossible for me as when I do drive it (on the weekends) I usually fill up 3 or 4 times. Checking the oil would be onerous on an hourly basis! However, if you shut it off, get out, start fueling, go in and get a Milky Way and a Diet Coke, then pop the hood and check it, you're obviously going to get a different reading then the day before when you shut it off, jumped out, and checked it right away. It does take some time to let it drain back to the pan. Also, the best most scientifically accurate way to get a reading is to check it first thing in the morning before starting the engine after it's sat overnight (or several hours) and has cooled and everything drained back. In that time, virtually all the oil in that engine should be back in the pan. I've checked mine this way and find it the most accurate way. Otherwise, you could check it in 5 minute intervals and get 5 different and completely bizarre readings. See where I'm going?

Sorry, BBC's consume oil. That's the nature of the beast!

Ya gotta crack an egg to make an omelet. Ya gotta consume some oil to make the power these engines do!

t-76y2kss · March 11, 2003

CMNT if my truck burned 1qt between changes like yours I would never complain that is normal to me.HOWEVER ive burned as much as 1qt in 600 miles of in-town driving empty.Oil was checked after overnight stay on level floor in my shop,checking at fuel stop is very inaccurate.I have yet to see a post on any website or heard from any of 3 friends who also have 8.1 oil burning remotely close to mine.Oil cost is not issue I buy it by the drum.After litigation G.M apparently agreed, they settled with me. I think my engine is on the loose side of loose as far as oil consumption.Ive owned about 40 vehicles in my life from 250$ beaters to my current 45,000$ DMAX personal rig none swill oil like this.CMNT you seem very knowledge,I have a ? for you why does my 600hp blown 2000 camaro ss 6sp use very little oil and I run it real hard 10.90s@ 127MPH just curious.

CMNTMXR81 · March 11, 2003

Mine burned that much at first too! But it has since calmed down!

Also, my 600Hp (actually mines about 550) Camaro doesn't burn a drop of oil either, but that's because I BUILT IT not too! Tight ring tolerances are the main reason. I set them up for non-nitrous, non-blower application. However, if it is an LS1 and you start running it past 7,000rpm, you're gonna run into oiling problems with it too! That being that the engine will suck it up soo fast leaving the mains dry because it can't return it to the pan fast enough. Soon after repeated runs like that, I gaurantee you'll start seeing some problems.

So far there are two methods to get it back to the pan.

1) some guys have plumbed home made oil return lines off the heads and tapped them into the oil pan.

2) Run an extra quart of oil (which is what I do).

LIke I said previously, if you have EXCESSIVE oil consumption (I.E. buring a quart between fill ups), there IS a problem. That I understand and say "get it back to the dealer". However, as I've repeated in thread after thread after thread....BIG BLOCK CHEVY'S CONSUME OIL! Expect some oil consumption with them period. It's the nature of the beast.

CMNTMXR81 · March 12, 2003

Just for you guys, I checked it last night after it had sat for over 24 hours. It's has been 1,800 miles since I last changed it and I was down a 1/2 quart.

odoh · March 13, 2003

I recall a year or so ago, there were many concerns re the oil consumption of this big block eng. Turned out that several reportedly found loose intake bolts allowing oil from the valve valley to suck into the eng for burning. The concerns/complaints diminished and now it appears that it is back.

bummed-n-Md · March 13, 2003

After being through what I did with mine, my opinion is that it is mostly a "communication problem" from GM. (every one knows about opinions, they are loke butt's, everyone has one and they all stink )

In the documentation with new vehicles, the old standard info (from the 60's and 70's) telling users that there is a 'breaking in period' on the new engines, has gone the way of leaded gas. I personnaly remember a couple of new vehicles I bought that I had to change out the 'breaking in oil' at 1000 miles, with follow up changes for the first 10K at 2K-3K intervals minimum. Once beyound 10k, the engine wqas considered 'broken in".

Many of the people moving up to these larger engines (especially in the SUV's and 'country cadillac' trucks) this concept is new to them. Many of them have come over form the mini-van and rice-burner world. in many of those vehicles, it was (and is) even advertised that the engines have no break in period. They read the users manual and it says that "you have a oil life management system on board. Change the oil when it tells you" (this was paraphrased). (Note that there is NO mention about potential high oil consuption in the early miles/life of the engine.) The only problem is that when you do that and you have a 'high consumer' like mine was, you will get a ENGINE OIL LOW warning message before you have 3000 miles. When you get that message and look at the dip stick, there is NO OIL readable on the dip stick (that means you are more than 2 qts low). When you go to the dealer (or more than 1) and get a 'thats normal' with no other explanation, (about engine break in or anything else) the consumer will then tend to get VERY Irate.

Once I figured out on my own that it is a break in issue (with the help of info on this site from people like CMX) I calmed down a lot and waited to see if the consumption rate would drop. As I posted earlier, the more miles I put on it the better it has gotten.

A lot of the grief people have over this issue would be elimimated if GM would simply put something about it in the manuals. Proper communications will prevent a lot of non-problems from being perceived as real.

bummed (no longer) :thumb: