[robsonap]

I have a 2011 335i X-Drive and am losing some boost. I just tuned my car to stage 1 with mhd and noticed it when I was monitoring the tune. I'm new to the bmw scene and figured the forums would be the best place to try and find a fix. The cars completely stock besides the charge pipe and I checked if that's leaking but it's not. Im about to hit 80k and I know the water pump has issues around then but I have no engine codes currently. Any info helps! Thanks!


https://datazap.me/u/robsonap/stage-...&data=3-12

(I don't think I logged this test correctly, but I'm going to do another log tonight, I heard you're supposed to do a pull from 3rd at 2 rpm, but didn't know that at the time I logged this)

[Nolan2221]

Originally Posted by robsonap

I have a 2011 335i X-Drive and am losing some boost. I just tuned my car to stage 1 with mhd and noticed it when I was monitoring the tune. I'm new to the bmw scene and figured the forums would be the best place to try and find a fix. The cars completely stock besides the charge pipe and I checked if that's leaking but it's not. Im about to hit 80k and I know the water pump has issues around then but I have no engine codes currently. Any info helps! Thanks!


https://datazap.me/u/robsonap/stage-...&data=3-12

(I don't think I logged this test correctly, but I'm going to do another log tonight, I heard you're supposed to do a pull from 3rd at 2 rpm, but didn't know that at the time I logged this)

Bump

[jlegelis]

>> I checked if that's leaking but it's not
Did you pressurize the system with a proper boost leak tester? The actual vs target are pretty off.... gotta be a leak somewhere.

Also:
- IATs increase pretty quickly. I definitely consider an intercooler upgrade.
- Seeing lot of corrections on random cylinders, and especially 5th gear. Strongly recommend you do plugs and (stock coils) if they've not been done.

[Info@mad-us.com]

Did you smoke test it or just visually looking for a leak? Leaks can surface when boost is applied.

[robsonap]

I didn't get to smoke test it but I could see via mhd I wasn't hitting my target boost, after doing some research I found it could be the boost solenoid, I had all of the symptoms. I ordered one today and it should be here by next Monday so I'll update you guys then

[robsonap]

Originally Posted by jlegelis

>> I checked if that's leaking but it's not
Did you pressurize the system with a proper boost leak tester? The actual vs target are pretty off.... gotta be a leak somewhere.

Also:
- IATs increase pretty quickly. I definitely consider an intercooler upgrade.
- Seeing lot of corrections on random cylinders, and especially 5th gear. Strongly recommend you do plugs and (stock coils) if they've not been done.

Appreciate the graph read I'll definitely get on the plugs and coils

[jlegelis]

Not sure why parts are being thrown at the problem... get a *proper* boost leak test and then go from there. Guessing there's a leak at the charge pipe coupler...

[robsonap]

Originally Posted by jlegelis

Not sure why parts are being thrown at the problem... get a *proper* boost leak test and then go from there. Guessing there's a leak at the charge pipe coupler...

I took the car to the dealership to use my warranty to see if they could find the leak and they said the car held pressure fine with no leaks, they did the smoke test. I don't just have everything sitting around to do my own smoke test. Also according to the forum I was reading the boost solenoid seems to be a common problem that most people don't even notice until they're trying to make bigger power, some even starting to fail under 50k miles. Plus it's a relatively cheap part.

[jlegelis]

robsonap any news?

[robsonap]

Originally Posted by jlegelis

robsonap any news?

I installed the boost solenoid and still had the leak, so I figured I'd give your advice a shot and reinstalled the CP. The leak was still there. After doing more research I tried replacing the CP o-ring, still nothing. I found a diagram of the intake system and really don't see where the leak could be coming from, I'm still getting no codes and holding pressure when tested. So now I'm thinking about replacing the vacuum lines and getting a vrsf Fmic to replace all old plastic. From what I understand it could also be the diverter valve or worst case scenario crack in the intake manifold. If you have any more ideas I'd love to hear, Thanks.

[wheela]

Do you know what pressure they're leak testing at? Your STFT gets very negative (pulling fuel out to keep AFR on target) as your rpm's rise, which could be explained by a boost leak. For MHD OTS tunes, the actual boost generally falls pretty short of target boost, if it wasn't for your really negative STFT, I'd almost think it looks normal for stage 1 OTS tune.

[wheela]

A bad diverter valve could explain low boost, but it doesn't explain your negative STFT, as your're not actually leaking measured air out of the system with a bad diverter valve.

[wheela]

Same with your boost solenoid and wastegate vacuum system: an issue there can create low boost, but shouldn't mess with your STFT.

[wheela]

Are you running the stock intake? If you're running an after market pipe in the location where your MAF is, it would through off your MAF reading, and could potentially explain your negative STFT.

[robsonap]

Originally Posted by wheela

Are you running the stock intake? If you're running an after market pipe in the location where your MAF is, it would through off your MAF reading, and could potentially explain your negative STFT.

I still have the stock air intake only thing I've put in was the CP. Do you think I should clean or replace the MAF? What else could cause stft?

[wheela]

Originally Posted by robsonap

I still have the stock air intake only thing I've put in was the CP. Do you think I should clean or replace the MAF? What else could cause stft?

That's a good question. Since your DME is pulling fuel, you're tending to run rich. Your MAF measures the amount of air going into the engine to calculate how much fuel to inject to hit your target AFR. Your upstream O2 sensor measures actual AFR so the DME can calculate fuel trims to keep AFR on target. So if any of those are not reading accurately, it could throw trims off. Or obvioulsy leaking air after the MAF can throw trims off. Or clogged injectors, but you can probably rule that out, as you're trims are pulling fuel out. I've also read that exhaust leaks before your O2 sensors can through trim off, but I'm not familiar with the ins and outs of that one.

It sucks to throw parts at something, I'd probably start with getting MAF cleaner and cleaning your MAF to see if that helps. And maybe see if you can find any air leaks the shop may be missing??? Have you checked the intercooler-side connection of your charge pipe with the hose clamp connection? If that's over-tightened, you can collapse the stock pipe underneath, creating a leak. You'd like to think the shop would have caught that, but who knows???

[robsonap]

Originally Posted by wheela

That's a good question. Since your DME is pulling fuel, you're tending to run rich. Your MAF measures the amount of air going into the engine to calculate how much fuel to inject to hit your target AFR. Your upstream O2 sensor measures actual AFR so the DME can calculate fuel trims to keep AFR on target. So if any of those are not reading accurately, it could throw trims off. Or obvioulsy leaking air after the MAF can throw trims off. Or clogged injectors, but you can probably rule that out, as you're trims are pulling fuel out. I've also read that exhaust leaks before your O2 sensors can through trim off, but I'm not familiar with the ins and outs of that one.

It sucks to throw parts at something, I'd probably start with getting MAF cleaner and cleaning your MAF to see if that helps. And maybe see if you can find any air leaks the shop may be missing??? Have you checked the intercooler-side connection of your charge pipe with the hose clamp connection? If that's over-tightened, you can collapse the stock pipe underneath, creating a leak. You'd like to think the shop would have caught that, but who knows???

Thanks for the info! I just tried cleaning the MAF and MAP sensors and did another log to find the issue is still there. I'm almost certain the leaks not coming from the cp boot but I could definitely see my mechanic missing that. Thinking back on it, when I took off my stock cp it was very weak and broke easily, I'm thinking maybe it could be the intercooler cp is cracked.

[joshhhua.__]

Originally Posted by robsonap

I have a 2011 335i X-Drive and am losing some boost. I just tuned my car to stage 1 with mhd and noticed it when I was monitoring the tune. I'm new to the bmw scene and figured the forums would be the best place to try and find a fix. The cars completely stock besides the charge pipe and I checked if that's leaking but it's not. Im about to hit 80k and I know the water pump has issues around then but I have no engine codes currently. Any info helps! Thanks!


https://datazap.me/u/robsonap/stage-...og=0&data=3-12

(I don't think I logged this test correctly, but I'm going to do another log tonight, I heard you're supposed to do a pull from 3rd at 2 rpm, but didn't know that at the time I logged this)

HELP!!

hey everyone! I have a 2008 bmw 335xi
I was driving one day and all of the sudden my audio completely stopped working. I have checked the fiber optics and they all work up to the front of the car. I have disconnected the battery and let the car reset and checked all the fuses. still no sound and I have zero clue what it could be. I have no sound even with the seatbelts off and if I leave my key in the car. I also charged the battery and it read full because I read the car could have gone into power conservative mode. any info would be greatly appreciated

[jlegelis]

Two things:
- Go back to stock, eg stock CP, stock tune. Still have a problem?
- Get a *proper boost leak tester* and pressurize the system and look for leaks with soapy water. The smoke test is worthless (too low pressure) IMHO.

Report back, and stop throwing parts at the problem fer chrissakes.

[robsonap]

Originally Posted by jlegelis

Two things:
- Go back to stock, eg stock CP, stock tune. Still have a problem?
- Get a *proper boost leak tester* and pressurize the system and look for leaks with soapy water. The smoke test is worthless (too low pressure) IMHO.

Report back, and stop throwing parts at the problem fer chrissakes.

I went back to stock and did a map it's on my datazap page. I don't have a leak at stock psi, but stft is still effected. I don't understand why y'all keep saying to stop throwing parts at it. It's not like I'm ricing out the car, if anything it's preventative maintenance and me upgrading something that was going to be upgraded soon anyways. Thanks for the advice though!

[njang92]

Originally Posted by robsonap

I went back to stock and did a map it's on my datazap page. I don't have a leak at stock psi, but stft is still effected. I don't understand why y'all keep saying to stop throwing parts at it. It's not like I'm ricing out the car, if anything it's preventative maintenance and me upgrading something that was going to be upgraded soon anyways. Thanks for the advice though!

It's just a slippery slope... Being that this is your first go at at a Stg1 tune and already thinking about a solenoid/fmic/dv just means that you're going to be in for quite the $ dump if you continue with that. But to each their own, I don't know your financial situation.

That being said, you have consistent timing corrections on all your cyls throughout your pull. Cyl 6 with the most. 1-2 or 3 deg is fine, but your car could be pulling power for knock prevention. Would highly recommend plugs and coils as your first step regardless. Check vacuum lines and PCV for leaks and make sure that chargepipe to fmic connection is cranked down good. I would lose 1-2 psi and hear a high pitched whistle when those clamps weren't tight enough. Also, did you do your pull with traction off? Doubt it would cause this but just curious. Also confirm you're running 93 octane? Just want to rule out the easy stuff and not insult your intelligence

[robsonap]

Originally Posted by njang92

It's just a slippery slope... Being that this is your first go at at a Stg1 tune and already thinking about a solenoid/fmic/dv just means that you're going to be in for quite the $ dump if you continue with that. But to each their own, I don't know your financial situation.

That being said, you have consistent timing corrections on all your cyls throughout your pull. Cyl 6 with the most. 1-2 or 3 deg is fine, but your car could be pulling power for knock prevention. Would highly recommend plugs and coils as your first step regardless. Check vacuum lines and PCV for leaks and make sure that chargepipe to fmic connection is cranked down good. I would lose 1-2 psi and hear a high pitched whistle when those clamps weren't tight enough. Also, did you do your pull with traction off? Doubt it would cause this but just curious. Also confirm you're running 93 octane? Just want to rule out the easy stuff and not insult your intelligence

Thanks for the reply! I'll get the coils and plugs next then. When I bought this car I was expecting to have to put some money into it to get it running correctly before going fbo. I guess I got lucky with the 335 and the only issue that seem to be the boost leak so far. I've scanned it with ista and have no failing modules or codes of any kind.

Is the diagram I have of the vacuum lines correct? I know the n54 has a lot of vacuum lines so this diagram seems a little bare compared to those. As for the pcv is there another way to test that other then the match test? And when pcv goes out, would I just replace the cover seal or the whole gasket?

When I do the datalog I have my dtc off completely and I'm running on 93. I've heard the log is supposed to be a 3rd pull only, no other gears. If I'm doing this wrong, please let me know! Thanks again for the reply!