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Nissan Excessive Oil Consumption - Maxima, Sentra, Altima

Many Nissan owners have reported excessive oil consumption for 2002, 2003, 2004 and 2005 models like Maxima, Altima, Pathfinders, etc., without being able to determine the root cause. I believe that, with the help of the right mechanic, I have discovered the cause and why it has been so elusive. The story should rightly infuriate many owners who have spent so much money trying to fix the issue.



I had the same oil consumption problem with my 2003 Maxima. Each time I went to the dealer, they basically played dumb as to what could be causing the problem. There were no external signs - no leaking, no smoke, etc. When I asked if they had ever seen anything like it - there answer was no. When I asked what is the usual cause? Their response was that owners were not changing oil at required intervals.



The problem with excessive oil consumption that became noticeable at around 70,000 miles, eventually took my engine out. Luckily, I removed it from the Nissan dealership where it was towed and had it taken to a garage - owned by a Nissan trained mechanic - previously trained at that same dealership. He recognized the underlying cause.



The excessive oil consumption was caused by faulty catalytic converter design. As the catalytic converters aged, they produced a sand like substance that was being sucked back into the engine during the common negative cycle. This created a comet like substance that created excessive internal engine wear. As engine oil was drawn into areas it should not be and burned off, it further accelerated the catalytic breakdown process.



IMPORTANT: This was a known failure by the Nissan designed catalytic converters. The proof can be found in the Nissan Sentra Catalytic Converter Recall for 2003 - 2005. Refer to Nissan Service Bulletin Number NTB08-023 for model years 2003, 2004, 2005 and Service Bulletin Number 501 for model years 2003, 2004. (NHTSA # 10024146 and 10018243).



Each Nissan vehicle owner that was impacted by this would have had a difficult time seeing the forest for the trees. Each would have been looking for issues for their particular model. However, this issue covers wide spectrum of models. For example, the Maxima 6 cylinder engine can be in the Pathfinder, the Altima, the Infinity, etc. How many models use cats produced by the same manufacturer?



The shell game: Nissan and the dealerships have had great incentive to divert attention away from the real cause. Why? To avoid a wider recall than with just the existing Sentra one.



Do a Google search and you will find some amazing coincidences. When Nissan was forced to honor their warranty, engines AND catalytic converters were often replaced without an explanation. When owner solutions were provided by dealers, the engines were replaced, or rebuilt without dealing with the cats.



Here is a clincher: Also reported is that, even though the catalytic converters had failed, the check engine lights never came on. Many do not know that the internal diagnostic computer can be made to ignore any area. It would be easy to make this happen simply by a normal firmware update that could take place anytime it is hooked up to the dealership's diagnostic computer. My computer did not report anything wrong with my Maxima cats even though they were almost non-existent and had much of this dust. One cats material was a ball the size of a small fist - sometimes blocking the exit of the exhaust, causing a loss of power. Also, searching online, you will find reports of mechanics acknowledging that Nissan stopped the computer from reporting Cat errors.



In my opinion, there has been a wide ranging cover-up about the Nissan Cats. This is something that should have been an obvious concern of U.S. Government lawyers when the original Sentra recall happened. Problem catalytic converters are not just restricted to the Sentra.



Oh, yes. I replaced the engine with a 84k used one. And, it had the same problem as the previous one. 1 quart of oil per 650 miles.
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Comments

  • edited March 2011
    I don't see how a faulty catalytic converter desgin can cause an engine to use oil. The converter is well downsteam of the inner workings of the engine. Also the Sentra uses a different engine than the Altima/Maxima/Pathfinder. As the Altima/Maxima/and Pathfinder V6 models all use the VQ V6.
  • edited March 2011
    Thanks for replying. There are 3 CATs in the Maxima and two are right against the engine making it very likely that the back pressure would suck the sand into the engine. The mechanic that noticed this was trained by Nissan regarding this same issue.
  • edited March 2011

    It's probably the other way around. The excessive oil consumption is causing the Catalytic converters to fail. The catalytic converters are not designed to burn that much oil.

  • edited March 2011
    More like a perfect storm. Once the sand gets inside and causes wear, it causes more oil to burn. Then, the more oil that is burned, gets scrubbed by the CATs, causing faster deterioration. Once this cycle is happening, engine failure can come fast. Testimonials about this are all over the web. I have seen some discussions owners placed on other sites taken down.
  • edited March 2011
    This is a board full of skeptics and since this all sounds unusual you will hear all sorts of alternatives. If you really think this is all a documentable thing and want it "out there" then I'd find a bored investigative journalist. The feds also have plenty of places where people can file complaints.
  • edited March 2011
    Thanks. Any suggestions where? I have worked with large corporations and know how the diversionary process can happen to try and lesson damages. The game becomes one of trying to wait out that 7 year window. I, and others, may have already lost, but there are many more who still might have a chance with this.
  • edited March 2011
    The cats you are referring to are called warm up cats, sometimes called pre-cats. Almost all cars have them these days, but for some reason, a lot of Nissan owners and mechanics believe this story. One other factor in this story that you didn't mention is that it mostly affects the high performance engines.

    Nissan uses a long overlap on the exhaust valves that extends well into the beginning of the intake cycle, that is how the negative pressure is created in the exhaust manifold. It is intentional so that some of the exhaust gas is drawn back into the engine. These engines use this in place of an EGR valve.

    I am not going to try to validate this story, my son has one of those Sentra Spec-V that is subject to premature oil consumption. His came brand new with a reman engine. The car was recalled off the dealer lot before it was sold to get the engine replaced. All Nissan did with these was disassemble them and replace the rings.

    One thing that Nissan did acknowledge was that they got hold of some "soft" rings and they are blaming the oil consumption on that. Now, to me, that is a believable story.
  • edited March 2011
    Racing engines with wide overlap cams and open, tuned, exhaust systems can indeed create a negative pressure pulse at the exhaust port..But mundane Nissan passenger vehicles have no means to "suck sand back into the engine"..The flow out the exhaust in today's smog engines is one way..Also, if Cats were breaking down and somehow pumping grit back into the engine, other makes and models would be affected as these components are manufactured by companies that supply more than one manufacturer..2002- 2005 models are considered museum relics by the manufacturer.. warranty commitment long expired..They view the products they make as disposable consumer products, like washing machines.. You should view them that way too...You should also consider that MILLIONS of Nissan owners do NOT have high oil consumption problems and are very happy with their vehicles..

    If Nissan dealers had been provided with the means to reprogram the OBD-2 government mandated emissions system so it would ignore CAT failure, this fact would soon be discovered by federally mandated emissions tests which would discover that the actual tail-pipe emissions were way over the allowable limit but the OBD-2 system failed to detect or register that fault. The Government (EPA) would be VERY unhappy at this fraud and Nissan would be in serious trouble, looking at a sales ban and tremendous negative publicity..

    If you feel Datsun has treated you unfairly, your only recourse is to never buy another vehicle from them...
  • edited March 2011
    Thanks again. I do appreciate the extensive knowledge and experience responders have been showing here.

    I do not know the statistics on when the average consumer trades in their vehicle (at what mileage), but this point may be pertinent to the discussion as well. If most people, as I would suspect, have traded their Maxima in before the excessive oil consumption has taken place, it is left for the second owner to notice. Another point is that the theorized cause would most often follow standard diagnosed lines. Even when the real initiating cause may have resulted by the CAT sand or breakdown, it would also be true that the excessive oil consumption is being caused by worn rings.
  • edited March 2011
    Thanks again. I do appreciate the extensive knowledge and experience responders have been showing here.

    I do not know the statistics on when the average consumer trades in their vehicle (at what mileage), but this point may be pertinent to the discussion as well. If most people, as I suspect, have traded their Maxima in before the excessive oil consumption became known, it is left for the second owner to notice, and the factory warranty has likely expired. Another point is that the theorized cause would most often follow standard diagnosed cause and effect lines. Even when the initiating cause may have been the CAT sand or breakdown, it would also be true that the excessive oil consumption is being caused by worn rings.
This discussion has been closed.