[Sgop335]

Ecu has no idea how much vacuum is clamped by the wg actuator. In other words the ecu sends the duty cycle signal not the wg. So dont expect wg vacuum to read 0 or something thinking thats 0% wgdc.

[Evil///M]

Reading the original post again and those are the exact symptoms I am getting.
I tested the solenoids a few days ago and they do have a little bit of bleed, one is very minimal, the other one is worse. So I ordered a new one and I hope that solves the problem. We'll see.

[Evil///M]

Originally Posted by Sgop335

Ecu has no idea how much vacuum is clamped by the wg actuator. In other words the ecu sends the duty cycle signal not the wg. So dont expect wg vacuum to read 0 or something thinking thats 0% wgdc.

No, it's cutting off all duty to the wastegates due to small influctuations in the system. Hence the 0% WGDC

[89mustaine]

Similar issues here. Limp mode consistently when engine is fully warm and during a long pull from gears 3+. I am getting 30FF Turbocharger, Charge-air pressure too low. Best guess so far is vacuum or boost leak, haven't had enough time to check everything yet. Any additional thoughts?

[expressfish]

think of the solenoids in a simpler way. The units have plungers inside that build pressure by moving back in fourth in the cylinder it is housed in. The ecm sends the signal upon demand for them to start moving to build vaccum. A bad one can be taken and shook or shaken back and fourth like a salt shaker, the plunger inside will be very loose. You can feel it banging back and fourth inside the cylinder housing. A good or new one is very tight when you do the same thing to it. Im guessing the plunger has seals at the ends that go bad. I had intentions to cut one open but threw them away in error. The vaccum test can be tricky due to the "vent" under the cap next to the nipples.

[clutchlee]

Does anyone have a step by step process to replace the solenoid?

[TrollToll]

Originally Posted by clutchlee

Does anyone have a step by step process to replace the solenoid?

Remove 4 vacuum lines,
remove 4 bolts,
remove solenoids.
Installation is the reverse of removal.

Moving reservoir will allow a little more room.

[clutchlee]

Originally Posted by Yournamehere90

Remove 4 vacuum lines,
remove 4 bolts,
remove solenoids.
Installation is the reverse of removal.

Moving reservoir will allow a little more room.

Thanks man. Appreciate it!

[blackturbo]

Anyone know the cheapest price for new solenoids?

[hjiang]

rmeuropean is the best price i got, just changed my solenoids last week

[FamilyManTrackSedan]

Originally Posted by hjiang

rmeuropean is the best price i got, just changed my solenoids last week

Is pierburg a reliable oe replacement brand?

[TrollToll]

Originally Posted by FamilyManTrackSedan

Is pierburg a reliable oe replacement brand?

I've tried to research it a bit and I think that Pierburg may be an oe supplier. My car has Pierburg and I'm fairly certain that they are original.

[FamilyManTrackSedan]

Originally Posted by Yournamehere90

I've tried to research it a bit and I think that Pierburg may be an oe supplier. My car has Pierburg and I'm fairly certain that they are original.

Thanks. Yep confirmed also with RM it's the OE supplier.

[zort]

Guys this is interesting. So when the engine off should the soleniods hold vacuum from the line on top each of the canisters ?

I am running a JB4 and mine bleed off however my buddy with a dinan tune hold on both.

I have a slow spool and no codes.

-B

Originally Posted by JamesM3M5

Just thought I'd share:

335xi 6MT. Complaint is of 30FF code, no other codes. Car builds boost just fine when accelerating moderate/hard. Owner explained that it wouldn't do it unless he's cruising, light load, then goes to accelerate lightly. Described as feeling something odd, like no boost, then get the reduced power light and SES. Shut off, restart, no problem.

Found a bad wastegate control solenoid. One you could pull vacuum on it, and it would hold with nothing else connected. The bad one would not hold any vacuum. Both wastegate actuators were fine, moved as soon as vacuum was applied manually, and were completely shut by about 7 inHg vacuum. No boost leaks, since it held full boost/hard driving and never went to limp. Vac pump pulled 25 inHg at idle.

I guess when it was trying to just build a very small amount of boost, the bad solenoid was bleeding off too badly. But when you ran hard, the increased vacuum supply from the pump and the working solenoid was able to actuate both WGs just fine. The problem only occurred under light load going to light acceleration.

[racermp]

Originally Posted by bpdef29

Didn't want to start a new thread for forum neatness purposes, although OP info is pretty unrelated.

My WG % in my logs keeps fluctuating under 5k (from like 30%-70% back and forth), and it's causing boost to rapidly fluctuate (which I can feel). Then at about 5k, the WG % steadies, as does boost. No underboost codes.

I recently did a full vacuum test and the solenoids seemed to be holding vacuum; should I replace them anyways? Car was doing this a few months ago and then I though I fixed it with an adaptation reset and now it's doing it again....

Hey there, did you ever figure this out? One of my n55s is doing it and I can't figure out why.

[bpdef29]

Originally Posted by racermp

Hey there, did you ever figure this out? One of my n55s is doing it and I can't figure out why.

Yep, it was the boost solenoids.

[racermp]

Originally Posted by bpdef29

Yep, it was the boost solenoids.

Thank you, I'll check them