jdanielca

sktn77a

iTrader: (2)

Well, they would, wouldn't they! 500 miles a quart in an LS is WAY too high for "normal" consumption. Whether you want to do anything about it, is up to you.

This is beginning to sound like Chrysler/Fiat!

joedaddy1

iTrader: (1)

Our LS burns about a quart every 5k miles.. just a v8 thing I guess..

using Pennzoil plat 0w-20

prichmon

iTrader: (1)

The thinner the oil viscosity the higher capacity to flow. Thus when you change to a thinner oil there is the possibility of increased burn rate.

Old poor boy trick to limit cost of an engine burning oil was to increase the oil viscosity to slow the rate. Going to a diesel weight of 15w40 or even 20w50 has a tendency to slow the burn rate.

I do not recommend this going to thicker oil especially in cold states.

Almost every OEM I have ever heard claim 1000+ miles per quart considered in specification.

UDel

I agree, not just a V8 thing, my GS430 didn't burn any oil. I always used synthetic.

joedaddy1

iTrader: (1)

PwrdbyM

I don't know of any manufacturer that doesn't cite at minimum 1qt of oil in 1k miles as being normal.

roadfrog

I remember someone posting that Lexus would not do an oil consumption test on their dime unless it was consuming at least a qt per 800 miles.

balanced6

Just curious - how are everyone's spark plugs looking with all this disappearing oil?

abs

For those of you experiencing oil usage, please confirm if the car always did this or if it only started at higher mileage. There are really only three ways the engine can be burning oil: 1) an external leak, 2) worn rings/cylinder allowing blow by to burn in the combustion chamber or 3) worn valve guides allowing oil to seep past the valve seal, down the valve stem and into the engine. With worn valve stems, there will typically be some black smoke directly upon startup from excessive oil that has leaked into the combustion chamber while the engine was off.

Direct injection engines can have issues with fuel dilution of the oil and also with excessive carbon buildup in the oil from the "soot" that the lean burn of the DI mode produces. These two things combined with an already thin oil 0W-20 and a relatively low HTHS of around 2.6, may be allowing excessive wear of moving parts. In this instance, running a thicker oil, like a 5W-30, before the oil consumption issue begins, could be helpful. One other thought on root cause. It may be that despite the D4S system helping to minimize the carbon build up on the valves, that there is still some carbon build up on the valve stem and that build up damages the valve seals over time. If the failure is due to valve seals and not rings/cylinder wear, then it makes a case for running ONLY top tier fuel along with a fuel injector cleaner every 5k miles before oil changes to help further control the carbon build up.

It would be very helpful to know if anyone has been able to diagnose the root cause of the oil consumption - either rings/cylinders or valve seals.

Caflashbob

My dealer service advisor mentioned more aggressive driving habits helps the engine run smoother.

No problem as I do drive the car harder than most and the plug change and the use of top tier gas has smoothed out the motor completely.

Doublebase

With me personally I had a lot of oil tracking though the PCV system, I would even have it track through the fresh air vent side, directly through the tubes and throttle body plate. Then I'd take a look past the throttle body plate, into the intake and with a flashlight you could see the oil just pooling there right on the intake floor. I began buring around a quart every 1,200 miles. My oil usage started right around the 150,000 mile mark and then got progressively worse, but up until that point I had really not experienced much oil usage at all.

One thing I wish I never tried - especially with a direct injection car - was push the oil intervals out to 7,500 miles. Before that I was doing 5,000 mile oil changes. Now at that time fuel dilution and low speed pre-ignition were not terms talked about with direct injection vehicles...nor wasn't oil consumption. Now it's all you hear with direction injection vehicles...shortening the drain intervals, fuel dilution, and low speed detonation. Those are the buzz words now; along with catch cans, intake cleaners, better oil designed for direct injection engines, soot, and baffle systems on PCV systems.

I wonder if a valve cover PCV baffle system would improve consumption in these cars - like I said, I noticed large amounts of oil coming through both sides of mine. The fresh air side can have oil problems during heavy throttle situations when manifold vacuum is low and blowby can't escape, but honestly I was very rarely in those situations when I drove, yet my car always seemed to have it come through that side as well. I imagine my engine blowby was too high...perhaps worn rings, or stuck rings. The soot buildup on the ring lands on direct injection vehicles have been noted to be high, wonder if removing the plugs and adding a cleaning solution to the cylinders and allowing it to sit overnight might help with some of these cars? Either that or the rings were just shot. I did notice a lot of oil on my spark plugs when I changed them...never misfires, but they were fairly covered (not all of them, but maybe 4). So I guess valve guides couldn't be ruled out, but that wouldn't explain the oil in the intake. And I just can't picture my rings being shot either, I always used a high quality Synthetic and although I did go 7,500 on a few occasions, for the most part my intervals were between 5,000-6,000 miles for the life of the vehicle. But yes, I did not have the oil consumption issues until I reached 150,000 miles or so....and honestly I probably still could have driven the car to 200,000-250,000 and beyond without issue (I think) because the engine always ran so smooth...no misfires, not one single check engine light the entire life of the car and plenty of power.

Caflashbob

My thoughts are running the engine harder puts more load against the ring forcing it into the cylinder wall to help it seat and lessen any glazing. Gasohol may not be helping oil ring seating?

i am at 7k oem oil change intervals. 0-20 uses a quart per 5k roughly.

Changed to oem 5-20 this time just to check consumption.

roadfrog

Bingo. BMW had this issue as well in their overly complicated PCV system.....at least in their 4.4

roadfrog

Mine were fine when I replaced them...no soot or build up whatsoever. I took a picture of them in my spark plug change DIY, if you want to have a look