I'm really not quite sure what's going on with my car.

In 5th gear around 60-75mph if I let off the gas and apply about 1/10th throttle the power seems to pulsate as if the engine is trying to push, but not getting power and feels as if I were running over a whole slew of little speed bumps. I can hear the turbo spool, but the RPMs only slightly go up. There's little power even when I go from 1/10th to full throttle until I let fully off the accelerator and accelerate again then the car accelerates smoothly.

It's as if in 5th gear it acts up unless I'm powering through the gear. All other gears are fine and I did notice when purchasing the car around 65mph it makes a slight low pitched vibration sound.

Any ideas? It sounds like the vibration is coming from the rear axle. Could it be the differential acting up?

 

Do you have an aftermarket bov? My car does it with the forge valve. Anytime I partially let off the throttle in 5th, it surges. If I fully let off the throttle then depress it again, everything is normal.

 

Yeah, I was considering that may have been possible though the car is completely stock. I suppose it might be boosting improperly under low RPM load? Oh the good times of owning a turbo car.

If you pin it while it does this it seems to bog. Maybe it's an injector problem? Maybe it's running too rich, therefore flooding the engine and causing it to bog? Though I pray if that is the case that it's not running too lean.

Did you find a solution to your problem?

Are you trying to say the BOV is releasing pressure when it shouldn't be?

 

Yeah, the bov seems to be venting and the car stutters. As long as I chop the throttle when I decelerate, everything is good.