Update for anyone following this thread:
Service found that the retailer had installed an aftermarket security system to the car (why, I have no idea, superfluous with the keyless system) and had attached it to the 12V. This drained the 12V. Anyway, they took off the aftermarket system and charged it up and it seems to be ok.

 

Hate to tell you this, but you have a big problem on your hands. My 2008 Altima Hybrid was working well until about 2,000 miles when all of a suddon, the same thing started happening... but there's more.

In addition to the inexplicable Engine revving which usually occurs when transitioning from ICE (internal combustion engine) to EV, I have another symptom, which is that at Highway speeds (> 40 mph after which Hybrid EV mode will NOT come on), when I coast, the Kw meter drops into charging (blue) territory, which it should not do. As a result, the car slows down and batteries charge rapidly (they don't need it at this point in time). But it kills gas mileage.

I went from 34 or so all around to about 26 with the same exact driving conditions, etc.

Brought it to Nissan on Thursday of this past week and every day they call me up and say "can't find anything wrong with it". I insisted on taking their so-called Master Mechanic (the only guy in the shop that passed the certification exam) for a spin to demonstrate the problems (made him drive) and he saw both within 5 minutes and said "that's not normal".

Today is Monday, they've had 3 full days playing with the car, nothing. They have been on the phone w/California, still nothing. The service advisor whom I do not trust now says "We can't seem to recreate the problem" which can only mean that they are getting ready to give up and give me the car back.

I sense a big problem... one that will be happening to more and more of us that has no remedy. Perils of being an early adopter, I guess, and at the expense of MPG (the exact reason why I bought the car).

Not happy.

 

Hate to tell you this, but you have a big problem on your hands. My 2008 Altima Hybrid was working well until about 2,000 miles when all of a suddon, the same thing started happening... but there's more.

In addition to the inexplicable Engine revving which usually occurs when transitioning from ICE (internal combustion engine) to EV, I have another symptom, which is that at Highway speeds (> 40 miles per hour after which Hybrid EV mode will NOT come on), when I coast, the Kw meter drops into charging (blue) territory, which it should not do. As a result, the car slows down and batteries charge rapidly (they don't need it at this point in time). But it kills gas mileage.

I went from 34 or so all around to about 26 with the same exact driving conditions, etc.

Brought it to Nissan on Thursday of this past week and every day they call me up and say "can't find anything wrong with it". I insisted on taking their so-called Master Mechanic (the only guy in the shop that passed the certification exam) for a spin to demonstrate the problems (made him drive) and he saw both within 5 minutes and said "that's not normal".

Today is Monday, they've had 3 full days playing with the car, nothing. They have been on the phone w/California, still nothing. The service advisor whom I do not trust now says "We can't seem to recreate the problem" which can only mean that they are getting ready to give up and give me the car back.

I sense a big problem... one that will be happening to more and more of us that has no remedy. Perils of being an early adopter, I guess, and at the expense of MPG (the exact reason why I bought the car).

Not happy.

 

I've had mine for about 11k miles and have not experienced the high revving problem. I do notice that if i am at highway speeds and remove my foot from accelerator that the car will slow down and the kw meter goes into charge mode. Also happens when going downhill without using brakes(I believe this is normal).
Is it possible that your brakes are too tight and causing regen breaking instead of just the normal charging that occures when you coast? Is it possible the car is in B (equivalent of low gear) or in D-drive when this happens?
One time, with a non hybrid car the breaks were so tight that the mpg was less than half the epa numbers.
keep us posted

 

Em,

Make sure they check the condition of the 12V battery. When this battery goes South, strange things happen to the entire hybrid system (from what I have read in a couple cases, but far and few between). If this battery lost a cell, it will put pressure on the system to keep charging it. Engine runs more, and as the original poster of this thread experienced, high rpm's at times.

 

Here's an update from my perspective...

The dealer called me again today after 4 consecutive days of saying "unsure that there is a problem; on the line with California" and fess'ed up that another Hybrid was in for a similar problem.

Based on this and the fact that I've seen many cases like this, I would say that there is a design flaw somewhere in the charging system, either due to a sensor giving incorrect readings, or a software bug that is acting screwy based on data from the various sensors.

Yeah yeah yeah, I've read the emails from folks saying things like "22,000 miles an not a single problem" but clearly there are a number of us WITH problems.

Will post again when I have some news.

-Mike

 

How many cases have you seen? And what was the problem in those cases?

I have heard of 2 that sounded similar. In both cases the battery was the problem.

 

I should have checked here earlier...

About a month ago I had exactly the problem originally mentioned with the engine randomly revving very high and oscillating between high and low, before shutting off. Also, the mileage was crap in the prior two days, down from about 35 to 37 to low 20s. I took it in and they performed an "idle air intake retraining" which actually fixed the problem.

Then, a week later, after returning from a week long business meeting, I also found the car dead in my garage. I had it towed, and the dealership has stated that the "reserve battery" was bad. They provided a free rental, but I have been waiting for 10 days for the battery to come in. They have found one in the adjacent county and it should be repaired tomorrow morning. Thanks to whoever mentioned the alarm system, they made a big deal about it when I bought the car and tried to charge me $1000 for it. I'll be sure to have it disconnected.

The maintanence guy has said that there may be something wrong with this reserve battery, as the replacement will actually be a newer model.

 

Back from a trip to Boston (I flew !) so no time to post an update, but I have one.

A day after I posted the last update, I received my daily call from the Service Advisor at Nissan (the other guy was off for the day). This chap was a bit more forthcoming in that he said while they have not been able to reproduce the problem (since the certified tech experienced it with me on the test drive), another care came into Nissan with similar but WORSE problems in that it refused to shift into gear.

Next day, the first Service Advisor called me up mid day and said "pick it up, we can't find anything wrong with it". Oh brother...

So I went to the dealer that evening and marched into the Service Mgr's office for an explanation. He didn't really have one, just kept yammering on about how they only have one master mechanic and they hooked up some diag gear for a test ride but could not reproduce the problem.

Well, I'm very surprised and somewhat happy to report that the care is normal again.

So... conspiracy theory time... did they actually replace something (batteries, as I've been reading) but don't want to tell me because if too much news gets out, nobody will be buying these? Or, did they update the firmware/code and it now is able to compensate for unusual situations where the batteries fault or discharge too low, or did they just perform a reset of the bat computer and it started out fresh as if this is a brand new car with no knowledge of driving patterns, etc.

(I read someplace that the car actually learns or records some information so it can better adapt to your driving and hopefully make the correct decisions in when it should charge, etc... who knows if this is true or not).

In any case, I'm about 200 miles in since getting the car back (including leaving it at the airport for 2 days) and it seems fine.

Hoping it will not rear it's ugly head again BUT very interested in hearing any conjecture, theories, or experiences of others with the same or similar problems.

Thanks,

-Mike

 

I too have been experiencing the same problems of high revving engine in my 2008 Altima Hybrid. I've only had it for about 3 weeks now and only 600 miles on the car. I've set up a time to bring it into the service department next week. I will be printing out this blog to show to the service manager and hopefully I can get some answers.

-Peter