[Andrew3424]

What's up guys once again the 335 matinence monster strikes again. I'm having a low boost issue with no codes. I have a 2008 n54 e92 fbo jb4 e85 flash normally peak at 19 psi but am now barely getting 10 pounds and it takes for ever to spool up my turbos. Also I noticed a different sound to my exaust, I have a remus race exaust and it now sounds like shit wtf could this be from. My charge pipe is fine no noticeable tears in my vacumn lines maybe an issue with my vacumn canisters or my boost solonoids anyone have a clue please help a now slow as shit 335 owner out thanks will post data logs shortly

[bpdef29]

Definitely post logs. I had issues with underboost and the car pulling boost target back causing underboost and huge surges/oscillations. No codes whatsoever. I did every leak test in the book (smoke, pressurized soapy water, DV compression) and replaced every vacuum line and nothing worked. Ended up doing the boost solenoids last weekend per Ken's recommendation and it finally fixed it.

The new solenoids are an updated part and I wasn't able to get the stock nuts (that have free-spinning washers) back onto the bolts due to their new shape and had to buy new nuts without "washers" to get them on.

Before:
Stock:
http://datazap.me/u/bdefiori/stock?log=0&data=2-4-21

Stage 1:
http://datazap.me/u/bdefiori/stage-1...=0&data=4-6-20

Stage 1+:
http://datazap.me/u/bdefiori/er-1-pl...=0&data=2-4-21

After solenoids:
Stage 2 (not a great log overall but shows near-perfect boosting):
http://datazap.me/u/bdefiori/stage-2...=0&data=4-6-22


I'd start with vacuum lines and the leak tests as they're cheaper, but definitely don't count the solenoids out like I did for months.

[Andrew3424]

http://www.datazap.me/u/andrew3424/l...log=0&data=1-4

[Andrew3424]

Originally Posted by bpdef29

Definitely post logs. I had issues with underboost and the car pulling boost target back causing underboost and huge surges/oscillations. No codes whatsoever. I did every leak test in the book (smoke, pressurized soapy water, DV compression) and replaced every vacuum line and nothing worked. Ended up doing the boost solenoids last weekend per Ken's recommendation and it finally fixed it.

The new solenoids are an updated part and I wasn't able to get the stock nuts (that have free-spinning washers) back onto the bolts due to their new shape and had to buy new nuts without "washers" to get them on.

Before:
Stock:
http://datazap.me/u/bdefiori/stock?log=0&data=2-4-21

Stage 1:
http://datazap.me/u/bdefiori/stage-1...=0&data=4-6-20

Stage 1+:
http://datazap.me/u/bdefiori/er-1-pl...=0&data=2-4-21

After solenoids:
Stage 2 (not a great log overall but shows near-perfect boosting):
http://datazap.me/u/bdefiori/stage-2...=0&data=4-6-22


I'd start with vacuum lines and the leak tests as they're cheaper, but definitely don't count the solenoids out like I did for months.

Yeah gotta get a vacumn tester how'd u come to the conclusion to change the boost solonoids and how do you test them

[bpdef29]

Originally Posted by Andrew3424

Yeah gotta get a vacumn tester how'd u come to the conclusion to change the boost solonoids and how do you test them

The theory is to T a vacuum gauge into the solenoid's "out" port that leads to the wastegate and loop it in through the window and read the vacuum at WOT. I didn't do that. I used a vacuum pump to close the wastegates to test them and then the only solenoid testing I did was checking the vacuum that they gave off at idle (which didn't prove anything as the solenoids performed fine at idle). I replaced them because it was literally the last possible thing that could have been causing my underboost that wasn't major. Install is easy and quick aside from the nut hiccup; the only downside would be dropping the $180 or so and it not being the culprit.

[Boost4me]

Not sure if this helps, but I was getting low boost with no codes too after having someone install my chargepipes. Turns out the person didn't tighten the maf sensor & that caused it

[Flex68]

Split hoses ?

[alexg212]

I say wastegates stuck open.

[cstmx_ryder]

Could be your boost solenoids.....I know mine went bad a while ago, and it was NOT boosting to target at all.....After I replaced both boost solenoids, she came back to life.

On a side note, when you said your Remus exhaust now sounds like shit, is it sounding louder like you're not running anything from the downpipes back?

Just curious because I'm not dealing with the sound of my exhaust as well, but I've been told that my issue now is with the wastgates actuator rod position than anything else.......

Anyway, good luck bro.

[NightStalker]

Originally Posted by Andrew3424

What's up guys once again the 335 matinence monster strikes again. I'm having a low boost issue with no codes. I have a 2008 n54 e92 fbo jb4 e85 flash normally peak at 19 psi but am now barely getting 10 pounds and it takes for ever to spool up my turbos. Also I noticed a different sound to my exaust, I have a remus race exaust and it now sounds like shit wtf could this be from. My charge pipe is fine no noticeable tears in my vacumn lines maybe an issue with my vacumn canisters or my boost solonoids anyone have a clue please help a now slow as shit 335 owner out thanks will post data logs shortly

For me it was my boost selenoids, I used CarlyBmw app and did a comprehensive diagnostics. Give me detailed stuff