First off my car is a 1998 jdm Evo 5 gsr, essentially the exact same drivetrain as an evo 8 for refference.

So I took a cruise down to visit a friend on saturday and my car was performing normally, smooth and pulling hard like it ussually does. We took a ride around and bogged a launch during that, however I noticed no difference after that the car still drove normally.

Fast forward to the morning after, I had let the car sit outside all night, I started it up and noticed a little more vibration than normal. No biggie I thought, having not done a properly cold start in a while. However once I started driving and taking the rpm's up the motor was vibrating stupidly hard, like if I had an open downpipe right below my seat. It does this while driving and while stationary, clutch in and clutch out. Could my front motor mount just be complete toast now from having the engine rock back and forth super hard during that bogged launch or do you suspect something more expensive has decided to raise it's middle finger at me? The car is sitting in the garage so I can check anything you guys think relevant and report back right away.

 

If clutching in and out doesn't change the vibration it's likely NOT the motor mount.
Is this vibration felt at the steering wheel or only from the seat?

 

Mainly through the seat, like the whole motor is going hmmmmm really loud (lame description I know haha), it's worse while driving and the motor bucks around alot more under partial throttle than it did. The motor mount is in pretty bad shape even if it isn't the cause. Think I should pull the lower timing cover and check the balance shaft belt?

 

Think motor mounts for steering wheel vibration and drive shaft u-joints or bushings if you feel it in the seat. my .02

 

Makes sense, I'll see if there's any movement there

 

The rubber in the front motor mount is all cracked for the inside outwards and looks to be almost seperated along the top, got a new urethane insert ordered because I was looking at doing it anyway. Anymore suggestions throw them out there and I'll keep checking stuff over lol

 

Bringing my thread back lol, motor mount has improved alot of things but not this vibration. Nailed it down the exhaust, if I move the rear hanger around or make it sit differently the vibration goes away and comes back at a different rpm, extremely annoying because I can't pinpoint what on the exhaust is doing it. Any other suggestions as to what I should try doing with it next haha, pretty stumped on this one