OIl consumption question

[SSPORT]

I'm getting a "Low Oil" warning light every 850 to 1,000 miles, and need to top up my LS1 with a quart of Mobil One at that time. Car is driving commuting miles, 12 to 13 mi. each way, city and slow (rush hour) freeway. LS1 has 33,000 miles on it, about 6,000 of that long-distance highway trips at 60 to 80 mph steady for hours. This motor has always used Mobil One 5W-30.

Does that quart-every-thousand miles sound reasonable and/or typical?

Thanks.

[AFASTYZFR1]

Mine does the same thing....any thoughts?

[RainMan]

As far as I am aware No, not normal for LS1. Mine barely uses any oil at all. Level difference on dipstick from oil change to oil change every 3 - 4K miles is negligible. Not anywhere near a quart! (21K miles). 18.5 miles each way to & from Kennedy Space Center where I work daily @ highway speed for 80% of drive.

How long has this been going on?

I assume you have. . . .
Checked for obvious leaks, oil stains where you park?
Presence of oil splash-back on underside of car?
Presence of wet oily residue on inside of exhaust tips?
Blowing blue smoke, start-up, idle, under load?
Checked spark plugs for oil fouling?
Does the engine ping under hard acceleration (Premium Fuel)? Sign of possible oil in combustion chamber. (Check Plugs)
Oil in Coolant/Overheating? (Unlikely)
Poor Fuel economy?
Any codes, SES light?

If you are burning oil, could be worn or damaged valve guide seals, guides, or however unlikely with only 33K miles, worn rings. Have rebuilt a few OEM engines that had bad rings or cylinder hone from the factory. Rings never seated and prematurely wore out. Engines really didn't smoke that bad but had excessive oil consumption.

Compression test and or leak-down test can give an indication but can be misleading sometimes. Unfortunately the only well to tell for sure is to yank the heads and check the rings/cylinders.

Be sure to eliminate all other possibilities before resorting to major engine work. Could be something really stupid like leaky oil drain plug.

[SSPORT]

Engine was replaced by dealer under warranty 33,000 miles ago with a brand new full GMPP LS1, so there are no rebuild issues.

Answers to above:

Checked for obvious leaks, oil stains where you park? NONE OBVIOUS (but park in a garage, so hard to tell own leaks from other cars' leaks; maybe put down cardboard overnight?...
Presence of oil splash-back on underside of car? NONE
Presence of wet oily residue on inside of exhaust tips? Black, runs rich , but No oil
Blowing blue smoke, start-up, idle, under load? NO
Checked spark plugs for oil fouling? DIDN'T CHECK YET
Does the engine ping under hard acceleration (Premium Fuel)? Sign of possible oil in combustion chamber. (Check Plugs) NO ENGINE KNOCK UNDER FULL THROTTLE, USES 93 OCTANE ALWAYS
Oil in Coolant/Overheating? (Unlikely) NONE, doesn't overheat
Poor Fuel economy? LOUSY; REAL-TIME IS AVERAGING APPROX 11-12 MPG. BUT THAT'S ALL STOP & GO CITY DRIVING, and the A/F-R is around 12.9 or 13 to 1, per last dyno, so it runs a little rich. Plus, I do open it up when there's a hole in traffic (or an a--hole behind me!)
Any codes, SES light? NONE (except "Low Oil" warning!)

Well, the GM warranty on the "new" motor is 50,000 miles or 3 years, whichever is to the owner's advantage (nice!), so I guess I can take it in and have it checked out by a dealer.

[SSPORT]

Mine does the same thing....any thoughts?

The reason I posted this question was that a couple of years ago, I think there was a thread that had a number of LS1 cars eating this much oil. The consensus may have been that it was not untypical. I just can't remember, and I guess I really ought to check the LS1.com technical archives.

[02z28ls1]

My car (29,000 miles owned since new) will use a half a quart every 1500 miles.There is another consideration here that I've noticed-it takes at least an hour or so on level ground before all the oil makes it to the oil pan,something about the little buckets around the roller lifters having small drain holes stock.This reminds me of a car that my parents bought new in 81-it never got many miles put on it until I bought it off them some years later.Even then I drove it short distances at a time until I got a differnt apartment that required me to do a hiway drive everyday.The oil usage on this motor was terrible even though the engine only had less than 20,000 miles on it-though was probably 10 years old at the time.Probably used a quart every 800 miles-until the hiway commute started,then oil life doubled an continued to increase the longer I drove it.My conclusion-the rings were finally seating from the fully warmed up hiway miles being driven regularly for the first time in it's long life.I sold this car in early 98 with around 36,000 miles on it-running as good as new getting 1800 miles or more per quart.Could be a similar situation going on for some people here-I have been using Mobil one since first oil change-considering going back to non synthetic for awhile to let it break in some more.Anyone with an opinion on this?

[TheDoc]

I have a 1998 Trans Am that began eating oil around 40,000 miles. Started slowly, becoming half a quart low between changes then a full quart, then more than a full quart. Took it to the dealer several times and documented the oil consumption. Deemed by GM to be excessive, but internal engine work due to wear and tear parts (rings) wasn't covered by my extended warranty. Chose not to spend the money and to check her oil levels more often, topping off as needed.

At about 68,000 miles I retrofitted the LS6 engine valley cover and associated PCV system to try to stave off the oil consumption. Worked for awhile, and definitely saw a difference in the oil pressure gauge's behavior. MUCH more oil pressure at high RPM. Engine used less oil for about 10,000 miles but it went back up to a quart every 1000 miles or so.

Car now at 92,000 miles and still chugging a quart of Mobil1 15W-50 every 1000 miles.

Until I have a good reason to tear apart the engine, an extra $5 in oil every month or so isn't gonna kill me. I hear rumors that the engines that burn oil like mine are the ones that go for 250,000+ miles. We'll see about that. heh

[rotwiler]

I have zero oil use issues with my 02, I race it all summer in ET drags and is my daily driver. I use Mobile 1 and change the oil every 5k, at most I may be a 1/4 quart off from when the oil was changed. When I get it changed they always give me the remainder of the Mobile 1 left in the last quart and I never have to add any more than that after 5,000 miles. I would put a cheap clear gas filter between the valve cover and the TB on the line like a catch can and see if it is getting sucked through your intake. If it is, I would think you would get some pinging too when the car lugs due to carbon buildup on top of the pistons.

Kinda off topic, but Might be a good idea to run some GM top engine cleaner through the intake and clean it up. I do this twice a year, ever since I was getting pinging and cured it, I was amazed at all the smoke it made cleaning it out. It does set off a multiple missfire check engine light, so will need to be reset. The oil is going somewhere, so would be a good idea in my opinion.

[jersaerocoupes]

GM's stance on oil consumption is 1 qt in 1500 miles is acceptable. if yours is still under warrenty take it to a GM dealer and they will do a consumption test. if they determine that it is using more than that they will make a repair. normally that means new rings but sometimes they will bore the block and install new pistons too.

[hammertime]

Poor Fuel economy? LOUSY; REAL-TIME IS AVERAGING APPROX 11-12 MPG. BUT THAT'S ALL STOP & GO CITY DRIVING, and the A/F-R is around 12.9 or 13 to 1, per last dyno, so it runs a little rich. Plus, I do open it up when there's a hole in traffic (or an a--hole behind me!)
Any codes, SES light? NONE (except "Low Oil" warning!)

11-12, really? I don't do a lot of highway driving in my car, but when I do take long trips, I usually get 27+ mpg. Average city, short trip, hard throttle after its warm driving, no less than 18mpg. If your car is running that rich, it's possible the cylinder walls are getting a heavy dose of fuel at times and contributing to ring/cylinder wear. Wouldn't hurt to get compression/leakdown test.

Also, my car uses a little oil too, but less than 1 qt per 1500 miles. I have a friend who did all the oil consumption tests and got nowhere with it, so I never thought to pursue it. I have noticed when the level gets a bit low, but not 1 qt yet, under hard accel in 1st gear the oil pressure gauge will drop at about 4000 rpm when the car is pulling really well, but I've never lit the low oil light. My pressure is always good otherwise, so I think it's possible to starve the car of oil without getting a low oil indication. Something to think about if you are nursing a car that really uses it.

[TheDoc]

I have zero oil use issues with my 02, I race it all summer in ET drags and is my daily driver. I use Mobile 1 and change the oil every 5k, at most I may be a 1/4 quart off from when the oil was changed. When I get it changed they always give me the remainder of the Mobile 1 left in the last quart and I never have to add any more than that after 5,000 miles. I would put a cheap clear gas filter between the valve cover and the TB on the line like a catch can and see if it is getting sucked through your intake. If it is, I would think you would get some pinging too when the car lugs due to carbon buildup on top of the pistons.

Kinda off topic, but Might be a good idea to run some GM top engine cleaner through the intake and clean it up. I do this twice a year, ever since I was getting pinging and cured it, I was amazed at all the smoke it made cleaning it out. It does set off a multiple missfire check engine light, so will need to be reset. The oil is going somewhere, so would be a good idea in my opinion.

I don't think I've ever heard pinging, does anyone have a sound clip of what I'd be listening for vs what I should be hearing? If it is pinging, I've probably been hearing it for so long that I would think it's normal now. I don't ever see any ping/knock codes coming from the engine and the dealer has never mentioned it to me. Occasionally I get a bad O2 sensor code on the passenger side but it goes away in 50-100 miles... So I'm not sure if it's related.

[rotwiler]

Best way to tell if it is pinging is when going up a hill in D or OD and you are only part throttle and can hear a clickity sound from the engine. There are alot of people on the boards with catch cans to collect the oil going from the vavle cover to the throttle body which helps prevent the carbon build up etc, but if I was going to do something the stop oil going in the TB I would think a longer line going from the valve cover to the TB and make it loop once with a zip tie to make it more difficult for the oil to have a straight shot to the TB. I bought a cheap clear fuel filter(about $3) to put inline to check, but never did it since I don't have enough oil consumption to even worry about. The first thing I would do to check for oil use is the line going from the valve cover to the TB and add something like the fuel filter I described that is clear so you can see if it is filling up. If over a couple days you see it fill up, you know it is where your oil is going. Is a cheap and easy way to tell, other than that I would think the rings... If you do discover the oil is going through the TB I would get a good catch can and clean the crap out of your engine with the GM top engine cleaner. Is only about $6 a bottle and 1 bottle will do your engine 2 times. All you do is pull the line off your valve cover to tb(the pcv) and put a funnel on it, pour a 1/2 bottle of the GM top engine cleaner through the line so it goes into the tb while the engine is running, it may start to stall out, then when the 1/2 bottle is used up. Shut the car off right away...may be good to have someone there to shut if off. Let it sit for 15 minutes, then start it up and let it idle, should smoke so bad it will make a cloud for a block...is kinda cool lol Then drive the car a few blocks after about 10 minutes to get it all out. You will get a multiple missfire code and just reset the code and it should be good. The pistons on the LS1 collect carbon on the top and is a common thing, so can't hurt. I swear by it and makes the car run so much smoother and no pinging. You can also use the Seafoam you can buy at any auto parts place and works almost as good, is only $3 and is what I use when I don't have time to get some of the GM top engine cleaner. I really enjoy my Z28 and try to do anything to keep it in top shape. I even run a bottle of marvelous mystery oil in the engine a few miles before the oil change to clean it up. Makes a big difference in the color from normal dark brown at the change to black after running the marvelous mystery oil. May sound unbelievable, but my car has less valve clatter and sounds quieter than when it was new, even on cold days. When I use Mobile 1 5w30 I hear more valve clatter and just doesn't run as good as with the 10w30, I would start using the 10w30 and see if it helps anything too. I know my car likes it.

With the O2 code, do you use octane booster? I had this problem and went away after I read a post about octane booster can fowl the 02 sensor. When I did the LT header install I took out my stock plugs and put in NGK's, I noticed a pearl like coating on the spark plugs and buddy that has a mid 10's turbo LS1 asked me if I used octane booster, which I did for a long time to cure the pinging which is why I did the top end cleaner. If it is doing that to the plugs I am sure something is getting into the 02 sensors too.


Sorry for the long post, just wanting to cover it, so if you do discover oil use through the pvc, then you know what to do after to clean up all that crap in your engine and prevent problems later.

[SSPORT]

Those are all good tips--I'd never heard of the the GM top cleaner, I'll give it a try. I used to use Marvel Mysterious Oil (!) frequently, but that was with a Jaguar V12 engine and I needed all the help I could get with that motor.

I've heard lots of guys recommend moving to 10W-30 up from the 5W-30; I may try it once the weather warms up a bit (March or April, should be ready for an oil change then).

And I will take it in for an oil consumption test. That tip about the line to the TB is interesting as well. It's going somewhere (the oil)!

[RainMan]

Best way to tell if it is pinging is when going up a hill in D or OD and you are only part throttle and can hear a clickity sound from the engine. There are alot of people on the boards with catch cans to collect the oil going from the valve cover to the throttle body which helps prevent the carbon build up etc.

With all due respect I must disagree on one point.

You refer to pinging and associate it with carbon deposits. Pinging is the audible ringing inside the engine otherwise know as Detonation, or the uncontrolled spontaneous ignition of fuel after the initial firing of the spark plug. Detonation is not associated with a foreign ignition source such as carbon deposits.

Hot Carbon Deposits, hot plugs, sharp edges etc. that get hot enough to ignite the air/fuel mixture can lead to a condition known as Pre-ignition. Pre-ignition is silent and deadly to engines. Pre-ignition can kill an engine in a matter of seconds. Pre-Ignition occurs well in advance of the spark plug firing and creates a tremendous over pressure condition as the piston struggles to reach TDC.

Detonation on the other hand, although very undesirable, normally is not immediately destructive. Pinging is usually a result of chamber design, fuel octane, heat, etc.

Here is a link I found that explains the differences between the two conditions in great detail.

It's a long read but good info.
http://www.streetrodstuff.com/Articl...ne/Detonation/

I mentioned in my earlier post that oil in the combustion chamber can lead to pinging.

Oil can be a source of octane reducing fuel contamination. Excessively worn piston rings, or worn or damaged valve guides and or seals may allow enough oil into the combustion chamber to dilute the fuel/air mixture. The dilution will reduce the octane rating of the fuel and can lead to detonation and eventual engine damage. While this scenario is not entirely typical of the engine that uses large amounts of oil because of worn or broken piston rings, it is possible for this situation to occur.

I had this situation in my Camaro a few years ago. I had a bad set of ill fitting intake valve guide seals that oil fouled my plugs and eventually lead to a bad pinging problem. Changed to the viton seals and the pinging stopped and stopped fouling plugs. Oil consumption dropped considerably!

[rotwiler]

what made me try the top engine cleaner was during a dyno at a well known shop in my area that does dyno tunes, I wasn't getting the pinging like on the street. The GM tech told me it was probably carbon on the pistons and the carbon will burn before the plugs and if it continues to use the Top end cleaner. It continued, so tried it and it went away. All I know is it worked lol

[YoMommasTA]

the only reason you don't see the oil smoke out the back while driving is the cats run so hot they completely burn all the oil up.If it wasn't for this GM would be fixing engines...what suprises me is these cars passing emissions burning that much oil you would think how could they pass?

[hatws6]

where can we get a catch can and a bracket for it?