N63 overboost with p0238 code

[TurboTerror]

I bought a 2011 750li for dirt cheap because it had a thrown rod. I purchased and installed a new engine from bmw. The engine came with brand new spark plugs and sensors already installed on the engine. I had to swap over everything else from the old engine including the MAP and MAF sensors. During startup, idle, and normal driving the car runs like a top. If you get on it from a dead stop in first gear or go a little over half throttle in higher gears the car throws a drivetrain malfunction with reduced power and a p0238. That is defined as turbocharger boost sensor A circuit high. There are no other associated codes. I swapped out the MAP sensors then MAF sensors (as those were the only old sensors from the other engine)but no joy still same p0238. I tried to use my scan tool to monitor some engine parameters but everything looks normal. I still have to get my multimeter and read for power, shorts or opens in the harness but i saved that for last because i figured if there was a short, open, or the sensor wasnt getting power then the car would throw the code as soon as you turned it on. The car is otherwise completely stock. There is nothing on the internet about this and im quickly running out of ideas.

[dworthy]

Welcome to the Forum!

I have learned over the years that "P" codes are not very reliable on a BMW. I would see about getting the car scanned with ISTA or a professional BMW diagnostic tools and watch the live data as the problem occurs, as you maybe barking up the wrong tree here.

[TurboTerror]

Welcome to the Forum!

I have learned over the years that "P" codes are not very reliable on a BMW. I would see about getting the car scanned with ISTA or a professional BMW diagnostic tools and watch the live data as the problem occurs, as you maybe barking up the wrong tree here.

I have both a Dcan (for my e60 535i) and an ENET cable but the only windows computer I have is an old laptop and have not been able to connect to my 750 through ISTA on it. Ill probably have to partition my macbook and run windows on it to get it to work as the other laptop is circa 2009. I appreciate the heads up about the P codes being unreliable.

[ptarditi]

I would look for either a sensor that might not be fully plugged in, or a leak in the induction circuit, you might try the connectors on the wastegate actuators first. Smoking the engine sure helps.
it doesn't help that the pressure sensors for the intake are located in such a hard place to access.

[bmwdirtracer]

Both of the above guys have pointed to what you need to do. P-codes are absolutely useless on this car; you need to see what ISTA tells you. As ptarditi explains, there's really not a damned thing on this engine that's easy to access.

[dworthy]

Another thought came to mind overnight, as I had worked on a Chevy Cruze earlier this week that keep getting a "Low Boost" code, and the MAF in the charge pipe was fouled. How dirty is the intercoolers on that car? Did you check to see if all the oil was out of the down/charge pipes?

[TurboTerror]

Surprisingly the intakes, intercoolers, and intake manifolds had no oil or residue in either side. Both maps and mafs were completely clean before I replaced them. But replacing them had no effect on the car. Car has 100k on it as such so do the turbos. One other thing of concern is the wastegate vacuum line routing. All the diagrams I find have two wastegate solenoids my car only has one. So right now it goes vacuum pump to vacuum reservoir, reservoir to solenoid, solenoid to Vacuum tee split into both turbo wastegates. But that same hose that goes into the wastegates also has another tee that goes to the (LHD)drivers side for the exhaust flaps where the diagram says it should be on the (LHD)passenger side.

I partitioned my MacBook and installed windows 10 on it but I’m still having issues getting ISTA to connect.

[bmwdirtracer]

As far as I know, ISTA doesn't do Windows 10; windows 8 is the max. Hopefully Abel (328 Power 04) will advise here.

Are you trying to get a cloned ISTA to work, or connecting to the factory item? Do you have an ICOM head?

[TurboTerror]

Well I think I know why I cant get ISTA to work. I have no idea what anything you just said means. The ista I got was off the bimmergeeks website. Same with the esys launcher. I cant get either one of them to work. Someone told me I could use inpa to read on the F01 I just wouldn't be able to write or code with it. I haven't tried INPA yet.

Ive been building/modding Asian and American cars for almost 20 years. But Im brand new to the euro scene. This is actaully the first car Ive really worked on that has had direct injection. So its been a little bit of a learning curve but nothing so overly complicated that I couldn't figure out... up until this software. Im completely lost when it comes to this.

[ptarditi]

Just re-read your first post, so you swapped injectors over, did you make sure to swap them to the same #cylinder of the original engine?

[TurboTerror]

Just re-read your first post, so you swapped injectors over, did you make sure to swap them to the same #cylinder of the original engine?

Yes I made sure I did them one by one. As I pulled them out of the bad engine, I installed them in the same position in the new engine. That's with the exception of the #8 injector.

As I said the engine had a thrown rod and I couldn't find any water in the intake manifold or intercoolers, the valves on #8 looked in bad of need of some walnut blasting but they were just like the other valves. The bottom of the rod was still connected to the crank and the bearings were not spun. The only conclusion that I could come up with was the engine was hydrolocked by a stuck injector. I replaced the #8 injector and was told that as long as the numbers were within 2 of each other(old was 578/219 new was 580/220) They didn't need to be coded. Still the car runs EXACTLY like it should until it gets deep into boost. It pulls VERY hard in first up to around 5500rpm where it throws the drivetrain malfunction. Same when im just half way on it, it pulls hard in gear until my foot goes just past half way or if im going up a steep hill less than half way then throws the malfunction.

[ptarditi]

There are two connectors that can be accidentally swapped down by the intercoolers and they both go to pressure sensors.

[bmwdirtracer]

Well I think I know why I cant get ISTA to work. I have no idea what anything you just said means. The ista I got was off the bimmergeeks website. Same with the esys launcher. I cant get either one of them to work. Someone told me I could use inpa to read on the F01 I just wouldn't be able to write or code with it. I haven't tried INPA yet.

Ive been building/modding Asian and American cars for almost 20 years. But Im brand new to the euro scene. This is actaully the first car Ive really worked on that has had direct injection. So its been a little bit of a learning curve but nothing so overly complicated that I couldn't figure out... up until this software. Im completely lost when it comes to this.

Please be assured that I meant no insult. I'm not a very good computer guy, except that I use ISTA everyday, for diagnosis and programming. I was hoping Abel might chime in here, because he's really the king of diagnostic computers. I use an ISTA program with an ICOM (factory) head unit, which makes ISTA work a little more flawlessly. I am unfamiliar with INPA....because I have ISTA D and ISTA P.

Now, please know that ptarditi is the best of the best, of BMW factory trained technicians. He's very modest, (unlike me)....but know that it's he, and Abel, whom I contact when I need advice. If ptarditi tells me to check for swapped sensor plugs, I'll be doing exactly that.

[TurboTerror]

There are two connectors that can be accidentally swapped down by the intercoolers and they both go to pressure sensors.

Can you be a little more specific? Do you mean there is another sensor that has the same plug as the map sensor that goes into the intercooler or the boost solenoid? Im just trying to be sure of what im looking for.

Please be assured that I meant no insult. I'm not a very good computer guy, except that I use ISTA everyday, for diagnosis and programming. I was hoping Abel might chime in here, because he's really the king of diagnostic computers. I use an ISTA program with an ICOM (factory) head unit, which makes ISTA work a little more flawlessly. I am unfamiliar with INPA....because I have ISTA D and ISTA P.

Now, please know that ptarditi is the best of the best, of BMW factory trained technicians. He's very modest, (unlike me)....but know that it's he, and Abel, whom I contact when I need advice. If ptarditi tells me to check for swapped sensor plugs, I'll be doing exactly that.

No worries, I haven't taken anything anyone has said here as an insult. I really appreciate you all taking your time to help me figure this out.

[TurboTerror]

Thanks for all the help i finally figured it out today. The vent for the solenoid is either clogged or broken. After checking all my wires triple checking the vacuum routing I finally decided to start pulling vacuum on everything i could get my vacuum pump on. I disconnected the lines from the B side wastegate (drivers side LHD) and noticed when i pulled a vacuum on it, it immediately bled off but when I pulled a vacuum on the A side (passenger side LHD) it completely held vacuum. I then ran a vacuum T from the b side over to the A side and let the B side solenoid run both wastegates. Took it out and now it pulls like a freight train all the way to redline. Now I just have to order a solenoid then figure out how im going to replace it without pulling the whole front end of the car apart.

[7seriesKing]

Hey turboterror I was wondering if you could help me out. I’m having the same issues on my 2010 750li. No check engine lights but throws a p0238 at high rpms. After 5000 it throws a malfunction and goes into limp. I bought brand new turbo boost sensors and that didn’t fix my issue. I even bought a new pigtail for bank A because I thought it was a short in the harness and still no luck. I’m now wondering if it’s a wastegate issue for that turbo either a vacuum issue or faulty turbo itself.