03 G35 Coupe 5AT

I have had my G for about a year now.. The last work I did to the car was about 6 months ago I put Headers on it.. to get ready for full exhaust..... With very limited space in engine bay and not wanting to pull all the stud bolts out to get the headers up there... i losened the Motor mounts ( I will get to why this is important later) and rocked the motor sideways to be able to get new headers up in from down below..

About 3 days ago i noticed a small vibration that i could feel when i would hit certain bumbs.. felt similar to the vibration of the engine coming though the frame some how... could only feel it in steering wheel... now... when i have it in slap-shift mode (5at) go to about 4k in first and let off the throttle.... i get a HUGE vibration coming from what sounds like the front of the car... doesn't do it when i hit the brakes so I don't believe it can be in the suspension... I checked the motor mounts they are all tight.. the only thing i can suspect it would be would be the tranny mount....

one other thing that I noticed is that when the car is in drive/reverse... if i hold the brake and slightly rev the motor, rather than it rocking perfectly sideways... it rocks sideways/towards the front a little bit... my reason for thinking it might be the tranny mount...

If anyone has any suggestion for anything else to check.. or how to see if the rear tranny mount is bad.. please let me know!

THanks in advance!!

Brad

 

Have you checked the tranny mounts? It would make sense that its either a motor mount or a tranny mount.

Your motor mounts can be tight but still be bad.

How many miles do you have on your car?

 

Why is it important?

 

Maybe the headers are bumping into the steering knuckle? I've seen this happen with turbo installs.

 

Yes the headers were hitting the steering knuckle.. but that is a completely different noise from the other in this case.. anyways though.. i have now replaced the transmission mount. everything on the steering is completely tight and no longer rubbing... and still have the problem... in slap shift mode i get a horrid vibration on decel in higher rpms... it has 90k miles... i have had it to Nissan a few times and they cant even figure out what it is... any information or any suggestions on what to check next would be awesome!!! I am about ready to crush the b***h!.

 

Engine mounts...

 

Last time I had it into nissan I had them check all the mounts.. they said that the engine mounts were just fine.. but the tranny one was bad. That's when I had them replace that.. they mentioned something about electronic mounts.. is that just sensors on the engine mounts?? Is that true?

 

There's a good chance that your busted tranny mount caused an engine mount to fail. You can't always tell just by looking at them.

 

thanks for all your advice for everyone who posted... when i was listening to it i got what seemed to be 2 very distinct noises... on when the header was rubbing on the knuckle and one that was supposedly somewhere else... last night i took spaced the header back a bit with some fine tuning... so that i didnt get the noise from the header and could pinpoint the other noise.... when i did that every noise was gone... now that i think about it now.. the "2" noises i was hearing was when the headed was bouncing off the header and when i used slapshift mode it was forcing it against the knuckle causing a much faster vibration which made it sound like it was a different noise... low and behold it was same problem that sounded different!! Anyways it is all fixed! thanks again for all the advice..

 

hey i just put in headers and it is rubbing against my steering rod, how did you fix it cause right now i can feel the vibration in my seat when i drive