I am getting a 2-3 psi flutter on my boost gauge under full throttle and a noticeable loss of power.

1st gear flutters between 11psi and 13psi
2nd gear flutters between 12-14 psi
3rd,4th and 5th all flutter between 13 and 15psi

DP wastegate, aftermarket gauge, black dial, chips.


- I listened for any surging, but did not hear anything.
- No vacuum leaks. 17-18 hg at idle.
- Wastegate looks tidy and no exhaust leaks.

Funny part is, it started doing it one day out of the blue. Then it went away for a couple days. Now its' back!

Would a failing BOV cause these symptoms?

Thanks

 

This is indicative of a positive pressure leak.
Some fluctuation as a load/gear increasses are normal, but you are exacerbated by a positive pressure leak, IMHO.
This is a leak that gets pushed open under positive, but then sucked closed under negative (appearing normal under vac.)

You need to place your hands on all the plumbing.

 

Leaky boost hose somewhere or a failing WG gasket. Check all your hoses and clamps after the turbo. A failing BOV will usually make a gobbling sound.

 

Make yourself one of these... I found my broken diverter valve right away.

 

ST is alive!?!?!?!

 

Yeah, who would have thunk?

 

Hmm, I've found that in 4th gear sometimes my car will not hold over 10 psi but in any gear lower than that it will hold at 15 psi. Also, if I start in 4th gear it's fine, but if I run 3rd out and shift into 4th quickly it just stays at 10 psi. I was actually beginning to wonder if it could be the diverter valve