zguy95135

Its a pretty recent thing, like it started in the last few days.


Its a strange vibration when I accellerate up hills or sometimes if its flat. And it generally only happens around 2000-3000 rpm. I first noticed it when I was driving on the freeway and was accellerating up a hill in 5th gear. It was pretty noticeable, I could feel it in the steering wheel and the floor. There wasnt any power loss, but the car shook some when accellerating. I turned off the freeway and into a parking lot, checked my plugs, oil, wheel lugs, tires for tread seperation... nothing. I revved the engine to 4000 rpm, no shaking at all. So I get back on the freeway and it feels completely smooth like normal.



It was fine until I was coming back from Irvine this evening, it started doing it again. Its strange because it comes and goes, but there isnt any power loss, or at least anything really noticeable (like it it was running on 3 cylinders). Also the car starts up perfectly like it normally does. Gas mileage isnt effected either, I still got 30mpg coming back.


It reminds me of what my dad's 300zx used to do, it would vibrate a little and the engine sound/exhaust would change pitch to a wierd lumpy sound (kinda like a WRX) but it wouldnt feel slow. He changed out the EGR and it was fine after that.


Is my EGR going bad? Its annoying because its the first time my car has done anything wierd and I need it to get to school.

STL+3.0CL

Can you feel it through the pedal? Your sure its in the engine (misfire) ? I have had bent rims start to vibrate at certain speeds on the freeway... Also, its very possible that your EGR is bad, but that would not cause the vibration you described.

zguy95135

Like I can feel the shaking through the whole car sometimes, its sounds like its coming from the engine. But I read that it could also be my inner CV joints, or engine mounts, or half shafts. Its wierd because if it was something like that wouldnt it be more constant? It only happens pretty rarely, 95% of the time its fine.

zguy95135

Well I'm 99% percent sure its a bad halfshaft on the driver's side. Mainly because its more of a thumping feeling then a vibration now. If I keep the speed under 75, it doesnt really do it except for when I accellerate, so I can still get around. Plus when I was driving in the parking lot where I live, I could feel a distinct thump (a small one) in the front left. So I'm pretty sure its a halfshaft.


I dont think its a bad CV joint, because the boots look new, and I dont think the halfshafts have ever been changed in 9 years.

So now I have to decide on whether or not I should just get it fixed locally (it might be hard since its so slammed), or wait for two weeks and drive it home to fix it there myself (I've done it before on my dads Z).