nanotech

Hey all,

About a month ago, I installed the OE DSMIC kit. At the time, the vac line I had to the BPV wasn't long enough to reach to install the BPV correctly, so I put it on backwards at first.

The car ran great, but made this chirping/squeaking noise at certain areas of the rev range once it warmed up a bit. It would not do it at WOT, just partial throttle and coasting. It was related to engine revs not road speed.

I figured it was the backwards BPV being forced open, so I replaced the vac line with a longer one and installed a brand new 710N BPV in the correct orientation. However, the sound persisted.

Car is not throwing any codes, logs look good, only problem is this noise. Any suggestions on where to look? I've checked and tightened all of the hose clamps around the passenger IC that would have been affected by the install and still the noise persists.

Another question to those who installed DSMIC, did you have to replace your BPV signal vac line? Mine was about 6 inches too short to install correctly. I'm puzzled since none of the instructions I read mentioned this as a problem.

FoKai

its easy for a clamp to mis-align with the hoses as they were being tightened.

for the rattle, are all rubber grommets in place? what about the bolts? all tightened down and not hitting against anything?

QuattroFan02

I just added an extension to that hose, didn't replace entirely

FoKai

same here. a lot easier than changing it out, although a new hose is ideal

diagnosticator1

Check the N279 solenoid valve, it switches vacuum to the DV independent from manifold vac/pressure. If the solenoid valve is leaking, then the control signal value to the DV, will be to high/low under certain conditions, allowing boost pressure to slightly unseat/open the DV causing the sounds you describe.

nanotech

Found one loose clamp at the TIP/bypass junction. Tightened it up, still no improvement. Hose was holding on fully there even without the clamp tight, which I found kind of odd; figured under decent boost it would blow off.

Couple more things
-only when car is pretty hot
-goes away when car is on a hill
-recurs when car is level or going down a hill

I'm starting to think maybe it's coincidence and it's an exhaust rub or something like that, if I get a chance I'll get the car on ramps and take a look at the downpipe area since it's the most likely candidate IMO.

nanotech

I'd replace it on spec but that area is kind of hard to work in without taking off the intake manifold, which I'm not sure exactly how to do safely...

nanotech

And the kit didn't come with any hose extension.

Actually, replacing the hose is pretty easy if you have a dremel with flex extension to cut off the hose clamp on the N279 solenoid under the intake. Would probably be a bitch otherwise.

diagnosticator1

and hold vacuum applied with a hand vac pump. While the other two ports are connected.
That is, deenergized, the NC normally closed port, will be blocked, and should hold vacuum. The NO normally open port/s should block and hold vacuum with the valve energized. OR Vise Versa.

nanotech

Ok, that doesn't sound like much fun to test without removing it