JB4 Problem..seeking wisdom

[ZsWhite]

Hey Guys,

About 2 months about 2 months ago I installed a JB4 in my 135i n54. All was fine until today. I was driving and rev'ed it a bit and got a yellow "half-engine" light. before I made it home the light went away, and reappeared a handful of times. I don't have the usb, obviously regretting that now to read the code. But I took the car out about an hour later and I had NO BOOST in my acceleration. However I could distinctly hear the turbo much louder than before, and as I released the accelerator I heard the pressure in the engine release, like a aftermarket BOV, however I do not have one. I parked the car and inspected my engine, and was unable to find any damage or anything out of place, however I have novice eyes. I let the car rest for about and hour, and started the car and everything was working when I rev'ed the engine a few times in park. I did not hear the turbo like before, it sounded normal.

Any advice, input would be greatly appreciated.

Thanks in advance.

[Rob.K]

You can still read codes with JB4 menu Speedo 1 - Tach 1
Then hit Volume down on the steering wheel to start reading codes.
Your blinkers will now flash, JB4 will then display the number of stored codes on the speedo.
Your blinkers will flash again, JB4 will now display the first code stored using the speedo.
0-9 on speedo indicates numbers, 10 and higher indcates Letters. 10=A, 11=B, 12=C etc
Ex. If speedo goes to 20mph, then 120mph, then 90mph, then 150mph would indicate code 2C9F

Hope that helps

[jturboawd]

Kind of sounds like either a boost leak or some how your getting into the economy mode, where you get no boost and can loudly hear the turbos

[ZsWhite]

Drove the car today got the code again and no boost to the car. The code was 30ff. So I guess that means I have a boost leak. What would you guys recommend doing? Should I pull the JB4 and take it to a shop to find the leak, should I look for it myself?

As always thanks in advance for the help.

[Chris.]

Check your charge pipe. They tend to crack under more than stock boost.

[jturboawd]

Either buy what you need to check it or put it on map 0 and take it in. If your taking it to bmw pull the jb4.

If you do it yourself make a cap to seal off from the passangerside intercooler, tap it, and pressurized the system to 15psi to check for leaks. It's kind of a pain if you don't have the little bits and a low pressure regulator, others on here may know a easier way.

I'd atleast check the charge pipe and.the recirculation valves.

[Ginger_Extract]

http://www.n54tech.com/forums/showthread.php?t=13114

This is a very thorough way of checking for boost leaks. If you're not mechanically inclined, check the charge pipe, if it's not that, or any of the more obvious signs, put it back to stock and call the dealer.

[Elsabor67]

What JB4 do you have? Do you have a G4 board or a G5/ISO board? Also, what map were you in when these things happened? Did you buy the JB4 new?? Are there any other aftermarket items installed like an intercooler, downpipes, etc?

You really need that USB cable ot be able to check all the settings on the JB4. Check every connection that you have and definetly check your chargepipe for any cracks around the collar that connects to the throttle body.

[neglectedX5]

Originally Posted by Ginger_Extract

http://www.n54tech.com/forums/showthread.php?t=13114

This is a very thorough way of checking for boost leaks. If you're not mechanically inclined, check the charge pipe, if it's not that, or any of the more obvious signs, put it back to stock and call the dealer.

I did what this guy shows here. Couldn't find a leak, nothing, I hooked everything back up, still got the code. I bought some vacuum line and replaced everything under the hood. I couldn't tell what line was bad since it was all covered in cloth but one of them had a hole somewhere. Code went away and hello boost. For $10 it was an easy fix.

[ZsWhite]

Hey Guys, Just wanted to update you. I went looking for the leak today and discovered the problem was the charge pipe right at the throttle body seal. I removed my JB4 and put my car back together. Went home and ordered a BMS performance chargepipe. Next week I will be installing it, then hopefully my car will be performing soundly as it did. Thanks for everyone's advice they gave me.

As for anyone else experiencing this problem. In order to see the leak where mine was I had to remove the air box. Otherwise I would not have had a chance of finding it.

I will post again to confirm that was the only leak, next week.

[Tony135]

Chargepipes are generally the first thing to go when you mod your car. I haven't had a problem with my ER Charge Pipe in the 55k boosted miles!

[BEAR-AvHistory]

Originally Posted by ZsWhite

Hey Guys, Just wanted to update you. I went looking for the leak today and discovered the problem was the charge pipe right at the throttle body seal. I removed my JB4 and put my car back together. Went home and ordered a BMS performance chargepipe. Next week I will be installing it, then hopefully my car will be performing soundly as it did. Thanks for everyone's advice they gave me.

As for anyone else experiencing this problem. In order to see the leak where mine was I had to remove the air box. Otherwise I would not have had a chance of finding it.

I will post again to confirm that was the only leak, next week.

Charge pipe problems with the added boost are a common issue.

[marc@x-ph.com]

Yup, that's why we always recommend swapping the CP out when you tune. I've had no issues with my ER CP running 20 psi for more than 40k...

[johngrossi]

Definitely sounds like a charge pipe issue if it happened under high load

[ZsWhite]

Hey Guys,

I swapped my old charge pipe with a new BMS Metal one. All is well and the car is running great. I have attached some photos, in case anyone was curious, might help someone out in the future. Thank you for the help and wisdom.
-Zach