Hi Folks,

I have been noticing this lately: When in Drive (D), and, when stopped (i.e. stop sign/stop light) I notice a vibration... most noticeable in my seat. I might notice a little bit of vibration in the steering wheel and shifter too, but mostly I notice it in the seat. Idle is 500 RPM in Drive (D). The RPM is not rough or erratic at all, just a vibration. A/C is on (does the same thing if A/C is on or off). If I put the car in Neutral (N), the vibration goes away. It also goes away when I put the car in Park (P). Putting the car in Neutral (N) or Park (P) also raises the RPM slightly, so I'm wondering if my RPM is Drive (D) is too low? What is spec?

Anyone else I've done some digging here on the forum, and I found other members post this same issue. Here is a list of all the possible problems taken from these other posts:

- dirty throttle bodies and/or dirty MAF.
- driveshaft (ripped)?
- motor mounts
- IAC Valve
- dirty air filters
- tranny mount
- idle re-learn

Of these, the only post I could seem to find where the member had posted a solution to his/her vibration problem, was motor mount (in their particular case). I'm wondering if anyone else has (or had) this issue? If so, what was it and did it fix the problem?

Vehicle is a 2015 Q40 w/ 61k miles. Just bought this car about a month ago (not at an Infiniti dealer). Still has some factory powertrain warranty left. I have been contemplating buying an extended warranty, but not sure if it's worth it. Got some quotes from Infiniti, and it's quite expensive.

Also, vehicle came with a Pivot Mega Raizin on it. This is some sort of voltage stabilizer or something. I had recently disconnected the battery to remove the Raizin to see there was any difference. Didn't really notice too much. I thought perhaps the accelerator pedal felt a tad stiffer and had slightly quicker response. Also, stereo may have sounded a little fuller sounding with perhaps a bass increase (lower registers). However, it's so subtle, I cannot discern if there is an improvement or it' just in my head. The vibration occurred before removing the Raizin as well. Will using the Raizin hurt anything?

Thanks,
JSB

 

Could be motor mount on way out or trans mount.

 

Thanks for your reply. We go on vacation in a couple weeks and I'm leaving the car with my mechanic. He'll have a whole week to drive it and go through absolutely everything on the car with a fine tooth comb. I'm gonna mention everything on the list above, plus all the response I get here. Motor mounts and throttle body cleaning were the two most popular responses on the other posts. It probably is a motor mount or something.

 

Throttle body wouldnt cause your symptoms. Bad mounts will take away ability to absorb vibration and transfer more to chassis like when you use poly bushings in track car.

 

Check the washer fluid reservoir retaining clip! The plastic clip can pop out, and the resulting vibration can only be felt while in D or N, and stopped. Steal a clip from the battery compartment if you have to.
5¢, 5 second fix.

 

Bro 500 rpm in drive is low, our cars should be around 650. Before I cleaned my throttle bodys n MAF I had a rough idle while in drive only because when you come to a stop the throttle bodys close but not completely (their in what's called idel position) so with my dirty throttle bodys my (D) idle when at a stop would jump back n forth from 530 to 650 n I would feel the vibration at lower RPMS but after I cleaned everything which is also pretty cheap n a real fun DIY project my idel in (D) was back to 650, I sometimes forget the car is even on lol. So I would start there bro because just like you the moment I put my car in neutral or park the idle would sit right at 650. Good luck.

 

Hi guys,

I'll try both of those suggestions (washer clip & cleaning TB's) . The idle on my car is not rough and does not fluctuate. It stays at 500 RPM when at a stop in Drive (D). On my way home from work last night, I stopped at a local park and did the Idle Air Volume Leaning (Throttle Position Learning). At first, I thought it took care of it. But then on my way home, I noticed at a stop light, the RPM was at 500 and the vibration was still there.

BTW, in my initial post, I said the vibration was also in the shifter and steering wheel. That is NOT that case. The vibration is not crazy, but it is noticeable and should not be there for a car of this type of engine. In fact, this slight vibration in the seat reminds me of the way a friend of mine's 4-cylinder 90's Honda Accord used to be when in Drive (D) and at a stop. Also, I tested the vibration when turning the A/C on and off. The vibration is still there when the A/C is off, but it is not a prominent. When I turn the A/C back on again, the RPM's do pop up a little, but then it settles off to 500 RPM.

Bottom Line: When the car is in Neutral (N) or Park (P), you feel nothing at all. As it should be when in Drive (D) as well.

 

I really believe once you clean your throttle bodys you'll be all good. Not sure if you know how to clean everything so I'm just going to post both videos, 1 shows how to clean n the other describes the process to correct the air flow n everything after cleaning. Keep us posted n good luck.

 

Thanks Redgoyabean. I'm hoping to have some time to clean them this weekend. Another thing I discovered... there are K&N air filters in my car (factory air boxes). Previous owner had put them in. In fact, other than the K&N filters and a Pivot Mega Raizin voltage regulator (removed a week ago), these are the only aftermarket parts on the car (that I have found thus far). The K&N filters are not crazy dirty, but they show some slight blackness in the dirty side. I'll wait though until after cleaning the TB's and doing a test drive, before possibly cleaning the filters. BTW, do these K&N filters make any difference on performance vs. factory filters?

 

From what I've read the K&N drop in fliters do make a difference, nothing to crazy but definitely a dfference. If I was you I would clean the MAF, throttle bodys n clean or replace the air fliters all at the same time, also how many miles on your car. Most ppl dont even think about replacing the PVC valves but there 1 of those thing that are super cheap, super easy to replace but if neglected can cause a problem but that's just on a side note n has nothing to do with your issue. Also you might consider a bluetooth OBD2 module, another super cheap mod (kinda) that allows you to keep an eye on your cars health. Paid like 25 bucks for the module n app.

 

Current mileage: 61,750

I just bought this car about a month ago. It had 60,800 when I bought it. I doubt the 60k was done. Nothing indicates it was when checking the service book (owner's manual) and when I checked the carfax report. I'm having my mechanic essentially do a 60k service (and then some) when we are away on vacation.

 

Kopy so you should be all good but that idle at 500 to me is noooo good n to honest I'm surprised no one else has chimed in lol. Hope I was able to help.

 

Redgoyabean:
Absolutely, thank you for all your help! In fact, thank you to everyone who responded thus far.

BTW, are you familiar with the Pivot Mega Raizin battery performance monitor that was on my car? Does these things just monitor voltage or do they regulate voltage to keep it constant? Below is a pic. I pulled it out of my car to see if I noticed a difference. At first, I didn't. But, then I began to take notice that the stereo may not have sounded as smooth or full sounding as it did before. Of course, this all depends on what music you're playing, so I was sure to use a test track. Now I'm not sure and I think it may be psychological. Another think I seem to notice is that the accelerator pedal was tighter feeling when using the Mega Raizin vs not. It seemed like the throttle response was quicker and more responsive. Then again, this can all be in my head. As far as things I did not notice... there was no difference in headlight brightness, or start-up speed, idle, etc.

 

I've read doing a grounding kit improves on the stereo somewhat n I have not idea what that is n if it works

 

Update:
I've noticed the vibration problem is intermittent at times. Sometimes when I come to a stop, the RPM will stay at 650. I get NO vibration when the RPM is at 650, Then, there are other times I come to a stop, and the RPM is at 500, which gives me the vibration. I took pics of my tachometer to show what I mean.