I have a 2011 Acura TL that is burning oil excessively. I am currently in the process of an oil consumption test. In general, will the oil burn more quickly if the crankcase is kept full or if I allow the oil to get low? I've been going back to the dealer periodically to have the oil topped off and am nearly to the end of the test (3,000 miles) and am just shy of the 1,000 miles per 1 quart requirement (oil is about 0.8 quarts low), so I want to be sure I exceed that in the remaining 300 miles. What would result in greater consumption, leaving it as-is (low oil level, broken down oil) or top if off with fresh oil? Part of me thinks the old broken down oil will burn quicker and if I add a fresh quart the consumption will slow down for a few hundred miles (which I don't want), but the other part of me thinks the engine will burn oil more quickly if the level is higher. Or does it not make a difference as long as the oil level remains above the pickup tube?

 

Providing there is no external leak and the oil is burning due to (most likely) bad piston rings then it makes no difference if the oil is high, low, new,or old!

The oil is being delivered by the oil pump which is picking up the oil from the bottom of the pan.

 

You are correct. It is bad piston rings. A bad design to be exact. The oil consumption increases dramatically after about 2,000 miles, so I assumed the oil was burning quicker because it is breaking down. If that's the case, then it seems like adding fresh oil would slow the consumption rate down temporarily. You don't think this is the case?

It never occurred to me how the oil actually makes it up out of the bottom of the oil pan because I never had a reason to think about it until now. Thanks.

 

Modern oils, especially synthetics maintain their viscosity way, way beyond 2K miles, oil that old is hardly even dirty!

 

I'm guessing the oil will degrade quicker if there is excessive blowby?

 

Agreed, the BIGGER question is what does the oil look like after 3k miles?

As for burning more/ burning less, the only mechanism that I could think of is that MIXING old (thicker) and new (thinner) oil SHOULD actually give you a THICKER oil.
It's counter intuitive, and about "gap filling" of molecules, often seen in chemistry labs
50 milliliters of pure water + 50 milliliters of pure ethanol =~96 milliliters.
However, if you measure by WEIGHT, you find that the weight did not change.
Similar effect happens if you add thin-new motor oil to thicker old-oil, the mixture is actually thicker. WHETHER you could actually DETECT this, or whether it would make a difference, well that's harder to guess.

 

mossman, I've been through oil consumption with Toyota.
I am not sure why you keep going to dealer to have oil topped?
The way I had it done, they did oil change, sealed drain plug and filler neck, then I drove for 1200 miles. Then, they drained oil and checked its volume. She failed.
Reason she failed, I drove her like a sports car. Was fun, actually.
It is my understanding that, if dealer filled engine, sealed it, and engine went so low on oil that it locked - it's on them.

 

The dealer asked me to come back at 1,000 miles to check the oil level, at which time it was 0.4 quarts low. They recorded the mileage and topped it off. I drove another thousand miles and it was again about 0.4 quarts low. They told me to come in to top it off a second time. Now I am nearly to 3,000 miles and the oil level is below the bottom tick mark, so I will be taking it in tomorrow to have them top it off one final time and conclude the test. The reason why I've been taking it back to them every time is because I want there to be absolutely no question as to the validity of the test. I missed the warranty deadline (by a mere two weeks), so I don't need any more reasons for them to deny my goodwill request.

 

They do know it's 0.4 qrt low how? By looking at DS? That's science? They should drain into graded container and measure volume, not look at DS.
Whatever. I can only speak from what I experienced and how it was done.

 

I assumed they used the dipstick. Regardless, American Honda refused a goodwill repair on the basis that I missed the warranty extension deadline by 2 weeks, and the dealer quoted me $7,500 to repair it. No clue how they came up with this astronomical figure considering the parts cost about $1,800 (consumer cost) and it's supposed to take 11 hours according to the service bulletin. That's about $3,500 according to my math. Anyways, no way I'm paying even $3,500 to repair a 9 year old vehicle. Guess I'll continue on as I have topping off the oil every thousand miles.

Other Acura owners with the same issue have been able to reduce their consumption by adding oil additives and fuel system cleaners, and a couple have switched to 0W-40 over the factory recommended 5w-20. They've also found certain brands of oil to hold up better than others. Castrol Edge with Titanium Technology is what has been recommended, as well as adding Marvel Mystery Oil additive and fuel treatment. Hopefully there's some magical combination that will cut down on the consumption. My consumption increases exponetially after I hit the 2,000 mile mark, so I'm guessing the oil is breaking down around this mileage. It seems pretty watery when I check it, and the J37 engine is known to run very hot. Thoughts?

 

what is the recommended repair new piston rings?
cleaners could help clean carbon built up on the rings and pistons and heavier oil may help also but would probably just drive it and top it off if when needed if it was me.

 

New pistons and new rings, hone cylinder walls if necessary and check/replace any other damaged components (e.g. camshaft).