Joe from Boston writes:
Here’s what happened to my 2003 Murano with 145k on the clock: the “service engine” light came on. So I took the car to dealer. They said the oil was low, and they put car on computer and said it needs a new engine, for a mere $7,000. I thought they were joking: they claim the computer says the engine is failing internally and there is nothing they can do about it. I had the oil changed and by my calculations, the car is consuming about a quart of oil every 1,400 miles.
This is shocking: at idle, the car runs as quiet as a church mouse and at highway speeds, it seems to run fine. There is no knocking in the engine, no oil leaking on my garage floor. This indicates the oil is being consumed inside the engine: there is no smoke coming out of the exhaust. Thus far, I have just been checking the oil every 500 miles and adding it as I go along.
The question is: keep the car and add oil, or trade it now? My overall feeling is that this is poor quality, I have a Dodge truck engine with over 200,000 miles and it does not burn one drop of oil.
Since my obligation is to our readers, sell this heap to a faceless corporation, not an unsuspecting buyer on Craigslist. Until TTAC gets word of a redesigned part/recall from the Nissan Mothership, put these 3.5L Nissans on your Shit List. TTAC commentator ponchoman49 said it well:
“I know a 2005 Nissan Quest owner with the same 3.5 engine with the same issue. The oil changes were done around 4-5K intervals, the van now has 81K miles and the engine uses a quart of oil every thousand miles or so, which is excessive. The engine was diagnosed as have scored cylinder walls due to catalytic converter failure and would soon need a rebuild.”
But it might not be a V6 only problem, Shane Rimmer noted that the four-banger versions are prone to killing engines:
“Nissan has had a few issues with pre-cats going bad. This has mostly plagued the 2.5L 4 cylinder, but it is not unheard of on the 3.5L engines. When it happens, catalytic material gets sucked back into the cylinders where it scores the cylinder walls.”
If you are lucky, the problem stops at the piston’s oil control rings, and the compression rings remain intact: which is why this Murano burns oil like mad but still runs fine. This is a design flaw that goes back to the location (and size?) of the small catalytic converters that mount close to the engine. While these “pup” or “pre” cats do a great job lowering emissions on a cold motor, Nissan obviously screwed the pooch. More importantly, they are NOT alone.
Bonus! A Piston Slap Nugget of Wisdom:
I have more than a tangential connection to this problem. Channeling my inner Michael Karesh, I recently inherited a 2002 Mercury Cougar (Duratec V6, 70k miles) with this problem. The Coog was a friend’s car, until we heard a pop under light throttle and it started running on five cylinders. After that, it was mine.
I found the solution to these engine-killing Pup Cats: exhaust headers. The aftermarket makes headers for the Ford Contour (yes, really) that delete pup cats. So I will bring the Cougar back to life, with an extra 60 ponies from a Taurus engine swap to boot. (That bit of hot-rodding is certainly besides the point, but why not have some fun at the same time?)
Sorry Murano fans, a quick Google search says that Altima headers will not work on your CUV.
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