LOL, let’s hope not!
I’ve read from one mechanic they found it to be a design flow in some engines:
- having some kind of “rough pre-filter” to get oil settled from oil fog and be located very closely to PCV port
- having this pre-filter to get gunked on high mileage cars
- have relatively narrow passage next to PCV valve/hose
If “stars align properly”, then if blowby gas goes fast enough, it simply gets oil “blown by the wind” up on the passage and into the hose if PCV valve is stuck open
Why no smoke on the back? Engine burns it together with fuel, so you don’t see it.
Normally you see it when leaking from the exhaust valve seals since oil gets introduced into exhaust gas, but not necessarily you see this effect from the intake valve seals - it gets burned in this case.
Anyway, this theory would explain symptoms described in this 7-years-old thread.
Just my 2 cents, as root cause was not found here…
I NEED TO KNOW WHAT HAPPENED!! lol… About the Altima… THIS IS WHAT I’M DEALING WITH NOW!! What did yall do? Did you ever FIX the issue? I bought this 2006 Altima (literally like 30 days ago -_- ) And within 2 weeks I added at least 8qts of oil. We changed the PCV valve and spark plugs, and then had to change both catalytic converters. (It went into “limp mode” after we thought the problem was fixed with the new valve and plugs, and the catalytic converter was the culprit… or so they saiiid.) The car CONTINUES to burn oil, but we only notice it when the white smoke starts, which only takes about a week max, for all the oil to “burn” out. I say “burn” because like mentioned above, there are no leaks, nothing that we can see or figure out. I’m hoping it’s just piston rings bc it seems like every other cause, we’ve addresses already. I’d like to know what happened with the Altima up there… What did your compression tests read? Everything ‘seems’ fine and dandy, but the oil is burning out of this car and I’m at a loss. I had the converters (yes, changed both. figured since so much damage was done bc of the pcv valve that the converters both needed to be replaced… start “fresh” if you will) done MAR 7, 17, the oil changed MAR 8, and today, MAR 13, I am out of oil, burning white smoke out my tailpipe. 
Only other thing we can think of is to change the piston rings. Sound about right? Anyone?
-Not a mechanic.
You have logged on to a 7 year old thread which will only lead to confusion. You need to start your own but seriously your problems sound too bad for forum help. You just need to put this in a shop and stop throwing parts at it.
I hate to say it, but I think you got hosed by the seller, whoever that may be
Did you buy from a dealer, or a private party?
If it was me, I would have contacted the seller, as soon as I discovered I was sold an oil-burning car. Yeah, they’ll probably laugh and just hang up the phone, but there’s nothing to lose. You should have done that BEFORE throwing parts at it.
Anyways, your car is probably a good candidate for either a VERIFIED good used engine, or a remanufactured engine
But I agree with Volvo . . . your best bet at this time is to pay for a proper diagnosis. And you should brace yourself for the worst possible diagnosis
Before you do that, I suggest looking at carcomplaints.com . . . apparently, it’s a sister website to this one. The number 1 engine complaint is excessive oil consumption. And the most common solution is a new engine
BTW . . . there WAS an oil consumption recall, but it’s now expired. Under certain circumstances, the engine would get replaced. Reading between the lines, I see this as an indication that this was a not an uncommon problem, and that the guys at the dealerships were replacing more than a few engines, to word it nicely. But you’re out of luck, as this has long expired
To burn 8 quarts in two weeks @danae_lees you’d have to have some pretty severe piston ring problems. Which would almost surely show up as poor engine performance, poor acceleration esp going uphill etc. If you don’t have all that, one unusual thing that happens sometimes that can cause big oil loss is the pcv system sucking oil from the oil pan into the engine. You end up with huge oil usage and quickly destroyed cats. The pcv system is supposed to have an air vent to allow air in, and suction to draw that air through the crankcase and into the engine. But if the air vent allowing fresh air into the engine is pinched or clogged, you can wind up sucking engine oil from the crankcase directly into the engine instead.
The seller of that Altima knew it was damaged goods.
You can run a dry and wet compression test to see what pops up.
There’s a bit more to “change the piston rings” than you might think.Cylinder heads off, this will also entail changing the rod bearings, and the success of any of it will depend upon how egged, tapered, and worn the cylinders and rod journals are along with things like a proper cross-hatch with a hone and how well the rings are fitted.
It may work out well for a while or go to hxxx in a handbasket two days later.
1 Like
New pistons and rings will cost about $3,000, this seems like a lot to spend on a used car.
There was a recall to reprogram the PCM so that it would go into limp mode if it ran out of oil, this would prevent a fire (most cars don’t run out of oil and catch fire). If oil consumption was found, the engine would be replaced. The recall has been changed to only perform the PCM update, Nissan support is not good.
Focus on the PCV valve is a common misconception, replacing the PCV valve will not solve oil consumption problems on modern engines.
The average price for a 2006 Nissan Altima for a dealer trade-in “in good condition” is $1500-$2500, and $2500 for a private sale. [I used 100K for mileage]
Yours is currently worth a lot less, due to the engine problem. If you invest $3000 in new rings, your car’s worth will only be back to the above price ranges.
As OK4550 eluded to, there is more to it than just replacing the rings. If you only do the rings, chances are you’ll quickly be needing to reopen the engine for something else.
I presume this is true as Nevada seems very knowledgeable about car repairs, but it seems counterintuitive. Seems there are three ways a problem with the PCV system could cause excessive oil consumption
Case 1. PCV valve fails 100% open. This would allow a large volume of air flow down the valve cover, through the crankcase, and back into the intake manifold, which seems like it could suck a lot of crankcase oil with it.
Case 2. PCV valve is ok, but PCV airflow into the crankcase is blocked off. This could allow a large vacuum to develop in the crankcase and that vacuum could pull crankcase oil directly into the intake manifold. Ever had a defective straw with a small hole or split in it halfway down? If the defect is above the liquid, you can’t suck much coca cola with that straw, right? But a straw with no hole halfway down, you can suck plenty of coca cola quickly.
Case 3. PCV valve is 100% closed. Pressure builds up in the crankcase, blows various seals, and causes oil loss problems.