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Discussion Starter · #1 · (Edited)
Erratic error codes 4521 & 4530

As the title suggests, and referring to previous posts I have made I had boost pressure issues which I was told were on the inlet side.

When the car got hot after a good 20 mile drive and gunning it a little it would throw up error codes 4521 & 4530 and seriously hamper performance and limit top speed.

Fast forward a few weeks of having to constantly clear codes to make it run better (can't clear the egr fault code - it's got a billet aluminium blanking egr now) I decided to replace the turbo side pressure converter with a pierberg item, the piping the goes to the reservoir and from the actuator to the the new pressure converter. I have replaced all the other hoses under the inlet, and as of yesterday replaced the glow plugs, a new Beru glow plug converter and the inlet side pierberg pressure converter. I cleaned the inlet sensor the sits right on the corner with a 1200 piece of wet and dry, washed out with wd40 and everything went back together.

Ran the fault code reader on it no more glow plug faults but now it's thrown up the swirl flaps! I don't have any swirl flaps as the were removed and didn't bother putting in the blanking plates. It runs strong and feels better, and apart from swirl flaps code and the unclearable egr all was well. However, i tried to put the foot down and it was pulling well until a flat spot that halted further acceleration. Running the fault code reader showed 4521 & 4530. A reset and all was ok again.

I really would love some help and advice please as its doing my head in!

Thanks in advance
 

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4521 Boost pressure control pressure too high
4530 Boost pressure control pressure too low

I'm no expert.
Does it drive fine after you've hit the 125 and slowed down?
Do you have the equipment to log real time data and upload here, it would narrow it down considerably.

My best GUESS, VNT sticking (odd that it's fine up to 125). I've not had much dealings with bimmers but I guess it's initiated from an actuator running off a vacuum hose (check the hose). I'd check that has no additional play. It should be hard to move by hand and should also move when WOT applied.
VNT is a simple system but it can stick when clogged up with soot. It's hard to remove the turbo on a drive but once off, easily servicible by anyone who knows how to use a socket set/spanner and wirewool.
 

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The views and lack of responses may well be that unless you're in Germany often, racing or tracking your car, performance over 125 is totally irrelevant.

Not having a go or a dig - just maybe putting on here what others are thinking.
 

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Agreed. I'm sure the fact that you are trying to drive at over 125mph on a 'closed runway' probably doesn't wash with many people on here...
 

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Not to dig at responses but where I live it's legal to do 125+ on some two way public roads although I wouldn't be posting it as a title :thumbsup

Although I agree on the title. Maybe change it to sporadic 4521 & 4530 error codes and teh car model/engine
 

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Discussion Starter · #8 ·
Good evening FPSChris! Thank you for the detailed replying will check out the link you have posted and see what it's all about. I don't think my fault code reader will allow me to save live data and upload it. I'll have to purchase some other diagnostic kit first I guess. I will have to set aside the time for a turbo off job, but I am fairly competent with scanners as I have done all the other work recently. I will let you know what I find. Thank you.
 

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Discussion Starter · #9 ·
I disagree, it's totally relevant to the speed at which the error occurs. Where it took place is subjective to people's interpretations. What I will say is I'm just on here like all of you for advice, shared resources of information and because I have a love for Bmw's. I've been a member of e30zone since its been running, and owned bmws since 2003. If people don't wish to help and share advice/knowledge because they got offended by something they read I guess I'm in the wrong place. I'm not the first nor the last person on here who has broken the speed limit of 70.

Just my opinion. FPSCHRIS thanks again, much appreciated. :thumbsup
 
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