So i just got a 06 sedan sport and i have about 1200 miles on it and twice ive noticed a weird shuddering feeling when driving. It happenes when im goin up a slight incline in a high gear (either 4th or 5th) and im barely on the throttle. Basically the car is at very low RPM (on the verge of downshifting) and i get a kind of shuddering/pulsating feeling from the car. It feels like im going over ripples in the road if that makes sense. Its almost like the car wants to stall or something. Anyone ever have this problem? Is my tranny defective? Obviously all i have to do is hit the gas and it downshifts and im fine but it doesnt seem like the car is supposed to do this? Any ideas?

 

Interesting...
Well, if you're going up a hill and are on a high gear, you're putting too much strain the the car. Ideally, you should use lower gears and I'm pretty sure you know that.
If you're not using Manumatic and are experiencing things like this...I'm pretty sure others with more experience will chime in. I only have 3,600 miles on my 06.
Could be the gas you're using as well. Even if you fill the car up with Premium, you'll be surprised at the quality you can sometimes encounter.

 

I have an 06 X, and have just over 2000 miles on my car. I have driven up many hills/mountains and never noticed what you are talking about. Although I tend to be accelerating when going up those hills. If you are in 4th or 5th gear, what speed are you at? I would just give it a touch more gas and keep it rev-ving at higher rpms to make the climb easier and put less strain on your engine.

 

ya this was happening in drive not manumatic. I was driving very casually and was barely on the gas. I was using 89 octane vs 91 but it doesnt seem like this should happen regardless. I can obviously just give it more gas but it just seemed odd...

 

How fast were you going and how steep was the incline...

 

i was probably goin 40-45 or so as i approached the hill then i didnt really apply any more gas so the car started to naturally slow down..the rpms went down a little and the car started to shudder like i was on a bumpy road. It wasnt too steep maybe a 15-20% grade?

 

is it the same hill each time, or is it every hill?

 

This is interesting. I really want to get to the bottom of this.
Do you have correct transmission fluid in the vehicle?
A transmission will not work properly or may even slip or shudder with the use of incorrect fluid.
I'm starting to think this is torque converter related.
I was reading through some Nissan Titan forums (I believe we're using the same transmission) and look at what I found:
"I have symptoms similar to yours. My truck shudders at ~ 46mph with little of no pressure on the accelerator. If I shift to 4th gear the shudder goes away. It appears this is a lockup issue or something."
Hopefully this points you in the right direction.

 

Owner's manual states the sedan with automatic takes 87 octane (regular unleaded).
I use 87 and have no such problems as you describe, but I live in flat Florida.

 

Correct. We have a map for Premium though. Filling up with better gas will result in better performance. IMO, if you can afford an Infiniti, you can also afford spending an extra $3-5 treating your vehicle with decent gas.
If I recall correctly, the Coupes only like Premium and nothing else. I know of one Coupe owner that filled his vehicle up with 87 and it would not start up.
I highly doubt fuel was the cause in this scenario. Check the torque converter as suggested. That may be the culprit.

 

At this speed, it would be typical for your torque converter clutch to be engaged with low throttle. Depending upon the balance between throttle input and road requirments, TCCs sometimes get confused. You can check it's function on a flat road at about 45 mph - by tipping in and out of the throttle, you can turn the TCC on and off. Your engine speed will increase by about 500 rpm and you should feel nothing unusual.

I had a problem like this with my old SHO & it was the plug wires (common problem). With low rpm and a slight load, the vehicle would shutter. Simply raising the rpms made it go away. It makes sense that lower octane gas could have a similar effect.

 

This is a very common issue for the sedans.. The sweet spot is 40mph @ 1500 rpm. If you keep the car at this speed for a few minutes it should jerk. It tends to happen more on inclines.

 

I've noticed the same thing. In regular auto (not manumatic) mode, going uphill, slight gas and slowing (not braking). Seems like the tranny doesn't downshift when it should so that RPM's drop too low and begins to shutter. Seems to downshift when releasing the gas or accelerating. But should downshift regardless because of the low RPM. I'll mention it to the dealer next time I'm in.

 

Sorry to bring back such an old thread, but I have this exact same problem with my sedan, 06 auto, I started noticing it at about 8k, I now have 12k on it. My G is stock. While it's shaking (shuddering), look at the gear shifter, it visibly shakes left to right. I don't get why it does this but is really worries me. To me it seems like when it does it, it will do it 3 times in one day and then I won't notice it again for weeks. I have tried to duplicate it going up the same road at the same speed and it just seems so random.

I have taken it to the dealer and told them about the issue but all they do is just point the framed logo on the wall that says "cannot duplicate the problem"

Has anyone had this issue resolved or acknowledged at the dealer? It's definetly not a normal feeling and cannot be good for the car (tranny) long term.

 

If you are in a high gear at a low speed and low rpm the car may be in a stall condition. There may be some times you need to use manual mode and downshift of give the car a bit more gas so it does it for you.