[Bimmer_Engineer]

I decided to log on the way to work this am and at the top of 3rd gear I got a chime of death and an engine malfunction warning. Pulled over and read the codes and I got a 30FF. I can't post the log right now because I'm at work and I can't get it off my tablet...so I'll do that later but I wanted to start trouble shooting now.

The car has an MHD stage 1 tune and when I look at the log you can see that at the top of 3rd the boost target was 10.5 psi but the car gradually dropped from being on target to about 6 psi until i let off the throttle. There was no loud pop and after I cleared the codes and the car feels like normal at partial throttle. I used the search before posting and most of the threads seem to be building 0 psi boost after throwing this code.

Am I correct in assuming that this sounds like something other than a charge pipe? I haven't logged or gone WOT since I cleared the codes, but I was still making 6 psi at the top of 3rd gear when the car threw the code in the first place...

[Antetokounmpo]

It could still be the chargepipe. And it could also be like 12 other things

[Bimmer_Engineer]

The WGDC dropped off immediately prior to the boost dropping from 10.5 to 6 psi...vacuum leak of some sort?

[Bimmer_Engineer]

So I finally got my logs downloaded...

Stage 1

https://datazap.me/u/jgradi1/log-153...=0&data=3-5-21

Stage 0

https://datazap.me/u/jgradi1/log-153...og=1&data=3-21

I'm thinking its a boost leak now based on the fact that I don't reach target boost on either stage 1 or stage 0...

[Bimmer_Engineer]

Originally Posted by Bimmer_Engineer

So I finally got my logs downloaded...

Stage 1

https://datazap.me/u/jgradi1/log-153...=0&data=3-5-21

Stage 0

https://datazap.me/u/jgradi1/log-153...og=1&data=3-21

I'm thinking its a boost leak now based on the fact that I don't reach target boost on either stage 1 or stage 0...

BUMP...still looking for a second opinion on this...it looks like a boost leak to me but I'm a total novice at this...

[b92]

Do you still have the factory plastic chargepipe? If so it's probably cracked but not letting air escape until the pressure builds up to a certain point.

[Bimmer_Engineer]

I did have it...planning on swapping in the new pipe tonight...

[torrque]

Originally Posted by Bimmer_Engineer

I did have it...planning on swapping in the new pipe tonight...

Did you swap it ? What is the result ?

I inspected mine and re-tightened it, no sign of crack or anything like that... Time will tell. I am away now, but when I get home I plan on dropping the pan and inspect the intercooler hoses, although I know I tightened them pretty well.

My car runs fine now, no codes or anything, but we're back on high 70 degrees, as opposed to over 100 like when it happened.

[Bimmer_Engineer]

Originally Posted by torrque

Did you swap it ? What is the result ?

I inspected mine and re-tightened it, no sign of crack or anything like that... Time will tell. I am away now, but when I get home I plan on dropping the pan and inspect the intercooler hoses, although I know I tightened them pretty well.

My car runs fine now, no codes or anything, but we're back on high 70 degrees, as opposed to over 100 like when it happened.

The Cobb charge pipe won’t fit with my intake...so I’m gonna either put the oem pipe back on or I’m gonna have to put the oem air box back on...

[upshift_downshift]

Originally Posted by Bimmer_Engineer

So I finally got my logs downloaded...

Stage 1

https://datazap.me/u/jgradi1/log-153...=0&data=3-5-21

Stage 0

https://datazap.me/u/jgradi1/log-153...og=1&data=3-21

I'm thinking its a boost leak now based on the fact that I don't reach target boost on either stage 1 or stage 0...

Looks like a boost leak to me. Off by 2 psi in some places, and a somewhat slow ramp-up. The WGDC dropping off is probably due to the code, where the ecu is pulling torque out. This is not a measured value, it's the command to the boost solenoids. So, the ecu is requesting the reduced MAP.

I am not entirely sure, however, why the boost target does not drop as well. I suspect that this is not the final boost target value used by the controller. It's probably some intermediate value, or a value for a specific "mode", e.g. "full-capacity" mode. There's probably a separate signal for "reduced capacity" mode that MHD is not logging. Someone else may know more about that.

You can see the WGDC slowly increase after the initial ramp-up as to try to push the boost higher to meet the target, and boost doesn't budge.

[Bimmer_Engineer]

Originally Posted by upshift_downshift

Looks like a boost leak to me. Off by 2 psi in some places, and a somewhat slow ramp-up. The WGDC dropping off is probably due to the code, where the ecu is pulling torque out. This is not a measured value, it's the command to the boost solenoids. So, the ecu is requesting the reduced MAP.

I am not entirely sure, however, why the boost target does not drop as well. I suspect that this is not the final boost target value used by the controller. It's probably some intermediate value, or a value for a specific "mode", e.g. "full-capacity" mode. There's probably a separate signal for "reduced capacity" mode that MHD is not logging. Someone else may know more about that.

You can see the WGDC slowly increase after the initial ramp-up as to try to push the boost higher to meet the target, and boost doesn't budge.

I was originally thinking boost leak too...but I can’t understand why the waste gates are opening before the boost drops. Also I didn’t get a code on the stage 0 pull...I didn’t realize I was missing the boost target until I logged it...

[upshift_downshift]

Originally Posted by Bimmer_Engineer

I was originally thinking boost leak too...but I can’t understand why the waste gates are opening before the boost drops. Also I didn’t get a code on the stage 0 pull...I didn’t realize I was missing the boost target until I logged it...

So you cleared the code and it didn't come back with the stage 0 run? That is weird. You'd probably need someone more familiar with BMW's control and diagnostic strategy to figure out why it's pulling out the wastegate at the top of third.

[RSL]

Originally Posted by upshift_downshift

So you cleared the code and it didn't come back with the stage 0 run? That is weird. You'd probably need someone more familiar with BMW's control and diagnostic strategy to figure out why it's pulling out the wastegate at the top of third.

PID has a timer. If it runs too hard for too long, it simply turns off and throws a 30FF. It runs at WGDC base only at that point. That drop in the second gear is loss of the PID additive. If OP logged WGDC base and WGDC after PID, you'd see both at the base values when it happens. PID running too hard may be from a leak or just tuning or both.

OP should try v8 maps instead of v7 or get a custom tune. v8 run things closer together (more like stock) to avoid this kind of issue on multi-gear pulls. Doesn't mean there isn't a leak still, but tune can cause 30FF just as easily as an actual leak. Either need to reel in the target for boost the boost control actually allows or need to retune boost control to be more responsive.

Boost psi below boost target also doesn't automatically mean there's a leak either for the same reason. DME targets load, not boost BTW, but load and boost are related. That relationship is relative and adjustable via tuning.

[Bimmer_Engineer]

Originally Posted by RSL

OP should try v8 maps instead of v7 or get a custom tune. v8 run things closer together (more like stock) to avoid this kind of issue on multi-gear pulls. Doesn't mean there isn't a leak still, but tune can cause 30FF just as easily as an actual leak. Either need to reel in the target for boost the boost control actually allows or need to retune boost control to be more responsive.

Okay...thanks for the response...but isn’t stage 0 basically the stock map? If there wasn’t a boost or vacuum leak and it was just a remnant of the way the car is programmed wouldn’t they throw 30FFs all the time under stock tunes?

[RSL]

Originally Posted by Bimmer_Engineer

Okay...thanks for the response...but isn’t stage 0 basically the stock map? If there wasn’t a boost or vacuum leak and it was just a remnant of the way the car is programmed wouldn’t they throw 30FFs all the time under stock tunes?

Yes, they are stock like and I don't see PID turning off in your stage 0 log. Are you getting 30FF on stage 0 in other pulls?

If it looks like anything to me, maybe somewhat lethargic boost control. Rattle fix or any options set during flash time? How old are the boost control solenoids? Checked the vacuum lines/connections over the valve cover, to the vacuum canisters, the barbs on the vacuum canisters, to the solenoids and WGs?

[Bimmer_Engineer]

The solenoids are original. I put the oem charge pipe back on and now I’m looking at the vacuum lines. I ordered replacement lines from verocious but they sent me blue by mistake. I’m gonna start tracing lines and see if I can find anything that are cracked and will replace them wholesale when my black lines come in...

[RSL]

Check all the plastic connectors/lines the hoses connect to also, including the barbs on the vacuum canister when you replace. If the BCS are 11+ years old, it probably wouldn't hurt to replace them either and are relatively cheap and easy to swap. Whether or not there is an actual issue on the vacuum side, it's just good maintenance for a car that age. Get the vacuum lines done and see if anything changes with WG movement first. A custom tune would be the ultimate solution, but I'd still try the v8 map instead of v7 and see if the 30FF goes away with how it sits now.

[torrque]

Just fyi, mine never came back since the weather cooled down, but I also re-tightened all my connections, so there is that... I suspect my charge pipe to have leaked when it was that hot. When I put my hand on it, it felt like a plastic bag, that soft from the engine/outside heat . I might order a VRFS one.

[Bimmer_Engineer]

So I changed my oil yesterday and I took the opportunity to take the undertray off and look at the intercooler connections...

The connection bw the intercooler and the lower charge pipe had a few drips of oil on it. I think this is indicative that it could be the Boost leak. I didn’t break the connection because I needed to put the car back together and I don’t have a new o ring anyway...what do you guys think?

[RSL]

Always possible, but doesn't necessarily mean a boost leak or even a leak there. Oil vapor that collects over time will pool at the the lowest point it can get to. Get the vacuum lines done? If it's still occurring after, pressure test is your best course to confirm or disprove a leak. Get the vacuum lines done yet?

[Bimmer_Engineer]

Originally Posted by RSL

Always possible, but doesn't necessarily mean a boost leak or even a leak there. Oil vapor that collects over time will pool at the the lowest point it can get to. Get the vacuum lines done? If it's still occurring after, pressure test is your best course to confirm or disprove a leak. Get the vacuum lines done yet?

I started the vacuum lines yesterday...working on it piecemeal. I guess my thinking about the oil drips is that oil molecules are larger than air molecules. So if oil can get past that seal then certainly air can too...

[RSL]

Originally Posted by Bimmer_Engineer

I started the vacuum lines yesterday...working on it piecemeal. I guess my thinking about the oil drips is that oil molecules are larger than air molecules. So if oil can get past that seal then certainly air can too...

Right, but my point is, just because that's where the oil drips are, doesn't mean it's coming from that connection or even necessarily from a boost leak. There's a good possibility it is, but could be higher in the charge pipe, from BOV/DV if venting to atmosphere, etc. It could also be something old, unless you know for a fact that it's not.

You're not even sure if you boost have leak to fix yet, so just be careful about getting sucked into chasing something that might not exist. If vacuum lines don't help (still think those should be done regardless and make sure to check or bypass the plastic tubes running over the valve cover), pressure/smoke testing to find leaks is faster and cheaper than replacing random bits on hunches.