This is kind of hard to explain but my car basically pulsates for a second and then stops for a second and does this continuously. I can only feel it when i'm idling regardless of what gear I am in. This is on a 99 Maxima automatic. The RPM's do not fluctuate and sometimes it feels worse than others. It kinda sounds like a helicopter in the distance (kinda muffled sound). That's the best I can describe it. I should also mention my car has been having a terrible vibration at high way speeds (70 - 80 mph) and also seems to shake like crazy any time it hits a little bump on the road so not sure if this has anything to do with it.

Only recent work I have done was the rear timing chain cover o-rings but this starting happening a good 7 or 8 months after I did that job. I've looked under the car and I noticed the LCA bushing seems to be shot and one of the sway bar end links so gonna replace those and see if there is any improvement. Also planning on replacing struts and shocks as my car has 180,00 miles and they have never been replaced.

Any other thoughts on what may cause this?

Thanks

 

Check engine light on? Does it even work?

Sounds like you have a misfire. Check for stored error codes.

A worn out and falling apart suspension sure isn't going to ride nice or be able to absorb bumps and control the vehicle. Replace the end links, control arms or bushings as necessary and maybe even consider a new set of struts and rear shocks.

 

Is it a low droning noise that fades in and out, and sounds like something's vibrating in the driver's side of the engine compartment? If so, that's a fairly common problem, with a number of threads. Someone fixed it by replacing their fuel pressure regulator, but I have the same noise and I can't trace it there, so I haven't tried replacing mine.

 

SES light came on few days ago but when I checked for codes nothing showed up. Reset the light and has not come back on since. DBear, yes it is a low droning noise that fades in and out about every second. I'll look into the fuel filter or Fuel pressure regulator to see if I can pinpoint it. I found a long thread with the same issue however the sound is a little different in their youtube video. Just like their issue this one can only be heard sitting inside the car and you can't hear it in the engine bay. This will give me a starting point at least! Will let you guys know what I find out. Thanks!!

 

FWIW, I've had it for some number of years, so it doesn't seem to be anything critical giving out. (I know, famous last words...) It's really frustrating, because you can't hear it in the engine bay. It makes sense that it would be something running through the fuel line to the filter and then into the firewall, but I used a stethoscope on the FPR and the filter and couldn't hear it.

 

In my case you can feel it in the filter with your hand. I havent tried to fix it because it doesnt seem to be detrimental.