After I got a tuneup and my timing advance I've noticed something. It is subtle and apparently only noticeable to me but it's definitely there. At around 1800-2500 RPM and ONLY in 4th and 5th gears I'm getting a sort of buzzing vibration through the cabin. I can feel it in my seat, the pedals and slightly through the steering wheel. It ONLY happens when I'm on the throttle and it seems to smooth out after 3000 RPM. The only other way I can describe it is that it sort of feels like I'm running on a rough road. Not bumpy, just not smooth. But as soon as I lift throttle it goes away. Any ideas?

 

I have something very similar, but the cause of my problem is my rear exhaust manifold rubbing the motor mount bracket. It buzzes at low rpms in every gear but I guess once I'm over 3500 the flex of the motor moves the manifold far enough away from the bracket. I need to grind that sucka down as soon as I can. Anyways, look for similar scenarios in your case. Is something loose? Stuck? Rubbing?

Does it happen in neutral as well or only under load? I assume since its only in 4th and 5th, it doesn't happen in neutral.

 

Yeah it does only happen under load. Don't you have all aftermarket exhaust (headers, y-pipe, and so on)? The only work done I've had on my exhaust is I had a bracket that was fixed bacause the exhaust was banging on, I believe, the crossmember. I also hose clamped the muffler. It's definitely coming from the front of the car. I'm just worrying it has to do with the tranny. Would worn bearings or other parts of the tranny in those gears leave symptoms like this? The smoothing out after high RPMs doesn't help me sleep easy considering a lot of things on this car smooth out like that (read: blown coils ).

 

Yeah, I have headers, but just thought of presenting my example to you as a way of illustrating some possible causes. I can hear buzzing and feel the vibrations in the cabin, on the pedals, steering, etc at low rpms as well which is why I thought it might help. Anyways, it could be tranny related, but I don't know enough about that to comment. Hopefully you'll be able to get more help on this.

 

I have somewhat of the same symptom, however mine started after I installed the ES subframe bushings and is only in 2nd and 3rd gear in the same rpm range.

I have the timing advance from TS, not from Nissan

 

After I got my warpspeed Y-pipe, i hit a bad speedbump and it got a little bent, started rubbing on a beam (crossmember?) underneath the car. I could not rebend, BUT got a pretty genious fix.....I found some braided stainless steel fuel line laying around the shop and wire tied it across the member, now it rolls back and forth with the exaust system.....

No problems for 5k miles.... don't know if this will help, but if your exhaust is hitting where mine was, you'll notice it isn't correctable through the exhaust hangars....

PM me if you need more info if this is the case...

J

 

I noticed something today when I was driving on my lunch break. I was cruising at around 50 MPH with the tach at around 2000-2200 in 5th gear. I was on the throttle and noticed the feeling in a sort of pulse. It was waving stronger to weaker as opposed to staying constant. Just more info to chew on. Still not sure if this is a sign of something broken or not.

 

You know what? I was having the EXACT same issue last night driving home from seeing "Running Scared." I noticed it at about 70 mph on the freeway. It was sort of a vibration in the steering wheel and the accelerator pedal.

 

I get the same feeling, but mine started after I installed my cattman catback. It is the B pipe hitting a cross member. I would check your exhaust first, make sure it isnt a coincidence something got bent at the same time of your other repairs.

 

Thanks, I will give that a shot.