[Habookedeem]

Hey guys been having this issue with low boost. I'm having no boost until about 35-4k rpm then only 3.2.

No Codes!?

I pressured checked the vacuum lines and heard a small hiss from the bottom of the charge pipe that I readjusted the hose clamp and it went away. But still only getting the 3.2.

I also have a quick intermittently sucking sound that is about .1 seconds long and causes a 50rpm drop. Here is a link to that.

I have my mhd flasher ordered and will be getting data logs hopefully this weekend. On my way now to get a hand vacuum pump to test the wastegates as I do have some wastegate rattle but nothing crazy.

Also I tested the boost solenoids and I could hear them release vacuum when I applied power, could they still be bad?

https://youtube.com/shorts/M2EtUOJOGSI?feature=share

Here's the link to the intermittent sucking. It's almost like a miss bust sounds like the engine is sucking air in the filters real quick.

Other than low boost/lack of power there's no driveablility issues and no limp mode.

[Habookedeem]

Update I vacuum checked the wastegate lines from the boost solenoids to the wastegates, the rear line won't won't build vacuum. I pump and pump with the mityvac and nothing. I hoping that's it if that sounds right? Only 3.2 lbs on one turbo though?

[Saif2018]

Originally Posted by Habookedeem

Update I vacuum checked the wastegate lines from the boost solenoids to the wastegates, the rear line won't won't build vacuum. I pump and pump with the mityvac and nothing. I hoping that's it if that sounds right? Only 3.2 lbs on one turbo though?

I'd start by replacing all vacumn lines, they're cheap.

[Habookedeem]

Originally Posted by Saif2018

I'd start by replacing all vacumn lines, they're cheap.

Originally Posted by Saif2018

I'd start by replacing all vacumn lines, they're cheap.

So I have to boost solenoids in order, we'll see how this turns out, should be here Friday

[Cloverdale]

Originally Posted by Habookedeem

So I have to boost solenoids in order, we'll see how this turns out, should be here Friday

Hope you ordered Pierburg cause there's lot's on the market that don't work. With your pump attached to the intake stack and finger stopping the output stack air escape, 30 lbs of pressure should still bleed off. The junk ones hold the pressure without bleeding off without having to block the output stack.

[Habookedeem]

Originally Posted by Cloverdale

Hope you ordered Pierburg cause there's lot's on the market that don't work. With your pump attached to the intake stack and finger stopping the output stack air escape, 30 lbs of pressure should still bleed off. The junk ones hold the pressure without bleeding off without having to block the output stack.

Originally Posted by Cloverdale

Hope you ordered Pierburg cause there's lot's on the market that don't work. With your pump attached to the intake stack and finger stopping the output stack air escape, 30 lbs of pressure should still bleed off. The junk ones hold the pressure without bleeding off without having to block the output stack.

The rear solenoid makes a farting sound when applying vacuum. Have to run to the store to get a magnet extension because I can't find mine and dropped the 10mm into the bottom of the bay 🙄. Should be on here within the hour and hopefully that was the issue. Also, I did get the pieburgs!

[Habookedeem]

Originally Posted by Habookedeem

The rear solenoid makes a farting sound when applying vacuum. Have to run to the store to get a magnet extension because I can't find mine and dropped the 10mm into the bottom of the bay 🙄. Should be on here within the hour and hopefully that was the issue. Also, I did get the pieburgs!

So I've come to the conclusion my boost issue is engine temperature related. I test drive the car, makes boost fairly well no real issue hitting boost targets. Then once it hits about 230-240 I'm getting 1-2lbs top at 7-8 target boost. Plugs, coils?

I parked and just sat with it running and did notice a small stutter or stumble here and there at idle, but no major issues under WOT other than not making boost?! The stumble isn't consistent maybe once every minute or two like a small miss, but still no misfire codes or anything else other than my 30ff under WOT but only when hot.

[Saif2018]

Originally Posted by Habookedeem

So I've come to the conclusion my boost issue is engine temperature related. I test drive the car, makes boost fairly well no real issue hitting boost targets. Then once it hits about 230-240 I'm getting 1-2lbs top at 7-8 target boost. Plugs, coils?

I parked and just sat with it running and did notice a small stutter or stumble here and there at idle, but no major issues under WOT other than not making boost?! The stumble isn't consistent maybe once every minute or two like a small miss, but still no misfire codes or anything else other than my 30ff under WOT but only when hot.

Post a log,

[Habookedeem]

Originally Posted by Saif2018

Post a log,

Originally Posted by Saif2018

Post a log,

https://datazap.me/u/habookedeem/log...38;data=3-4-20

[studio54]

I also have some small miss at idle, like once per minute sometimes, maybe plugs or injectors, but I don't think it will cause your boost to be under target.

It's weird that DME do not even try to raise WGDC, it stays flat while being under target. Load req vs actual also have this delta, but maybe that's how the stock tune works.

During your vacuum test, you said the rear wastegate actuator wasn't holding vacuum, I think it's very problematic, a new boost solenoid won't help. How the front was holding ?

Does the car always acted like this or did you buy it like that?

I think you should try to flash stage 0 again, with your MHD license you just ordered.
(The name of the flash is weird "Stg0-1" ? usually it's "Stg0")

[Saif2018]

Originally Posted by Habookedeem

https://datazap.me/u/habookedeem/log...=0&data=3-4-20

230-240F is normal operating temp, shouldn't cause any issues with engine running at that temp.

Have a read through this guide...

https://bmwtuning.co/bmw-n54-30ff-en...-repair-guide/

Looks more like an issue with your Wastegates, but might be a good idea to do a smoke test to eliminate any boost leaks.

[Habookedeem]

Originally Posted by studio54

I also have some small miss at idle, like once per minute sometimes, maybe plugs or injectors, but I don't think it will cause your boost to be under target.

It's weird that DME do not even try to raise WGDC, it stays flat while being under target. Load req vs actual also have this delta, but maybe that's how the stock tune works.

During your vacuum test, you said the rear wastegate actuator wasn't holding vacuum, I think it's very problematic, a new boost solenoid won't help. How the front was holding ?

Does the car always acted like this or did you buy it like that?

I think you should try to flash stage 0 again, with your MHD license you just ordered.
(The name of the flash is weird "Stg0-1" ? usually it's "Stg0")

Originally Posted by studio54

I also have some small miss at idle, like once per minute sometimes, maybe plugs or injectors, but I don't think it will cause your boost to be under target.

It's weird that DME do not even try to raise WGDC, it stays flat while being under target. Load req vs actual also have this delta, but maybe that's how the stock tune works.

During your vacuum test, you said the rear wastegate actuator wasn't holding vacuum, I think it's very problematic, a new boost solenoid won't help. How the front was holding ?

Does the car always acted like this or did you buy it like that?

I think you should try to flash stage 0 again, with your MHD license you just ordered.
(The name of the flash is weird "Stg0-1" ? usually it's "Stg0")

The rear will vacuum up them bleed off in a few seconds. The front seems to bleed off a lot slower.

I bought the car like this. Tuned stage 2. I could feel a pronounced boost raise at about 4k rpm. Which I believed to hopefully be a vacuum leak somewhere. Which I think the tune was adjusting for missing boost targets. I should've data logged it there too before going back to stock.

I'll double check the stage 0-1 and possibly reflash.

I also reached down and I have a small amount of play in the wastegate but nothing crazy. I'm going to try the "adjustment" for the rear turn actuator rod and see if that helps any. And if it does, I'll just be going to new turbos, I was looking at the Vargas? Any opinions? Nothing crazy, prefer reliability (however unreliable) over crazy power. Looking to make the 450-500 range. I have catless dp, fmic, intake.

Thanks for the replies!!

[Saif2018]

Originally Posted by Habookedeem

The rear will vacuum up them bleed off in a few seconds. The front seems to bleed off a lot slower.

I bought the car like this. Tuned stage 2. I could feel a pronounced boost raise at about 4k rpm. Which I believed to hopefully be a vacuum leak somewhere. Which I think the tune was adjusting for missing boost targets. I should've data logged it there too before going back to stock.

I'll double check the stage 0-1 and possibly reflash.

I also reached down and I have a small amount of play in the wastegate but nothing crazy. I'm going to try the "adjustment" for the rear turn actuator rod and see if that helps any. And if it does, I'll just be going to new turbos, I was looking at the Vargas? Any opinions? Nothing crazy, prefer reliability (however unreliable) over crazy power. Looking to make the 450-500 range. I have catless dp, fmic, intake.

Thanks for the replies!!

Don't buy Vargas (dodgy turbos with many people complaining about their reliability) , go for RB 1/2's

https://www.rbturbo.com/products/335i/335i

Email Rob at RB Turbos...

rob.rbturbo@gmail.com he'll be able to point you in the right direction and offers discounts as well.

[studio54]

Originally Posted by Habookedeem

The rear will vacuum up them bleed off in a few seconds. The front seems to bleed off a lot slower.

I bought the car like this. Tuned stage 2. I could feel a pronounced boost raise at about 4k rpm. Which I believed to hopefully be a vacuum leak somewhere. Which I think the tune was adjusting for missing boost targets. I should've data logged it there too before going back to stock.

I'll double check the stage 0-1 and possibly reflash.

I also reached down and I have a small amount of play in the wastegate but nothing crazy. I'm going to try the "adjustment" for the rear turn actuator rod and see if that helps any. And if it does, I'll just be going to new turbos, I was looking at the Vargas? Any opinions? Nothing crazy, prefer reliability (however unreliable) over crazy power. Looking to make the 450-500 range. I have catless dp, fmic, intake.

Thanks for the replies!!

Well according to your log, it could be a vacuum problem/wg actuators not holding correctly, you slowly building boost to 4000 rpm, then it falls down..

Just a therory, but maybe during the first seconds of your pull, the vacuum previously built in vacuum canisters helps, and when canisters empty of vacuum + wastegate actuators not holding, the vacuum source can't keep up and it will fall down, opening up wastegates resulting in less turbos pressure.

Did you test how much inhg arrive at the lines with a vacuum gauge?
Measure at vacuum canisters and after boost solenoids to eliminate a vacuum source issue