My early 99 manual has a vibration that comes and goes at 1000 rpm. When it has this condition it makes a dull sound through 1400 rpm. When it goes away it takes off like you released the e-brake. I'm wondering if my turbo is beginning to fail. I'm going to check the turbo shaft for play. Anybody have any other ideas? Thanks in advance.

 

I checked the turbo and it had no movement in and out and just little side to side. It seemed the same as the last time I checked it.

 

Does it do this all the time when below 1400 RPM? Or is it just when it is cold?

 

It has only happened after it is warmed up while driving slow on forest service roads. I'm wondering if my ebpv is malfunctioning. I'm thinking I should disconnect the ebpv at the pedestal to test this theory. This has only happened a couple times so it is hard to troubleshoot.

 

That would be an easy test...Worth a shot. That was what I was kind of leaning towards.