Overboosting - 30FE

[expressfish]

update, it was the solenoids. Ive only read of a handful of others that had overboost issues and the solenoids solved it. Usually it is the opposite. Add me to that list. I also read several different posts about pulling vaccum on the solenoid. The only method I found that worked was with solenoid nipple side down / or or standing up so that the plunger inside the body slides down towards the nipples. Make sense ? Otherwise you really cant pull vaccum properly, it will just relase the vaccum thru the vent under the little hood on the solenoid body. If you shake them you can hear/feel the plunger in the solenoid slide back and forth. My old ones were very "loose" in the body and bled down right away when vaccum was applied. The new ones were very tight and held vaccum very well. I aslo dont remember the car shifting at 7 grand ? I seems to hold the gears alot longer. Maybe its just me. I should have gutted one of the solenoids to see what the enternals looked like and posted some pics as Ive never seen anything about them on the net. $175 dollar fix plus new vaccum lines, anxious to feel the power cobb "sport" puts out now that Im not overboosting / limp moding !

[sharkatron]

Yeah I definitely see your point. There are so many factors at play here, and what makes it difficult is trying to find what it is that is causing the overboost condition. You say that it can't be the solenoids but from what I have read around, and even others who have posted in this thread have commented that the solenoids were the problem. So what you're saying is that because it is a heat problem, the issue is the difference in temp between the 2 TMAP sensors (of which one or both are defective) causing the issue?

TBH I am getting sick and tired of changing one thing after the other with no improvement at all. I will clean up the 2 TMAP sensors and report back. USD-AUD is so $#@!e for us at the moment I don't think I want to fork out that kind of money right now. $10 degreaser at the autoshop sounds more appealing for now.

[sharkatron]

update, it was the solenoids. Ive only read of a handful of others that had overboost issues and the solenoids solved it. Usually it is the opposite. Add me to that list. I also read several different posts about pulling vaccum on the solenoid. The only method I found that worked was with solenoid nipple side down / or or standing up so that the plunger inside the body slides down towards the nipples. Make sense ? Otherwise you really cant pull vaccum properly, it will just relase the vaccum thru the vent under the little hood on the solenoid body. If you shake them you can hear/feel the plunger in the solenoid slide back and forth. My old ones were very "loose" in the body and bled down right away when vaccum was applied. The new ones were very tight and held vaccum very well. I aslo dont remember the car shifting at 7 grand ? I seems to hold the gears alot longer. Maybe its just me. I should have gutted one of the solenoids to see what the enternals looked like and posted some pics as Ive never seen anything about them on the net. $175 dollar fix plus new vaccum lines, anxious to feel the power cobb "sport" puts out now that Im not overboosting / limp moding !

Good to hear it got fixed! Thanks for the update.

[///MPOSTER]

@sharkatron could you please upload your csv file, as the original link is not working for me. I want to take a look at your PWM and verify its behavior.

Thanks

[///MPOSTER]

Never mind I got it to work. No need to re-upload.

[///MPOSTER]

log 24 , great log, you never went over 17.5 psi.
The log looks great with almost no throttle closure.
Lambda bank 1 &2 are matching.
WGDC starts out at 68 tapering down to 32 mid range and back up to 40's at the higher range.

log 25 , okay log, you went over 17.5 psi for a short period.
The log looks okay with some major throttle closures in the 20's-40's between 3700-4200 RPM.
Lambda bank 1 &2 are matching.
WGDC starts out at 68 tapering down to 27 mid range ( at throttle closure) and back up touching 50 at the higher range.

log 26, bad log, you quickly over boost to 18.74 at 3800 RPM as the throttle closes majorly until 5500RPM when WOT value returns and the boost returns.
Lambda bank 1 &2 are matching, (except at 4037RPM)
WGDC starts out at 45 tapering down to 27 mid range ( at throttle closure) and back up to 40's at the higher range for a short time.

Conclusion, I do not think you have an issue with a sticking waste gate arm/flapper/actuator, as your banks are aligned correctly. I don't think you have a tuning problem because your WGDC does not go high un-expectantly causing overboost. It also is confirmed by your statement that it happens on a stock map. I do not think it is a stuck open boost solenoid because I would expect that the WGDC would be low almost all the time as the computer sees no need to increase it. Also I don't believe the boost solenoid would get stuck in an energized state (always allowing vacuum to pass to the actuator). They normally fail closed which is the relaxed state which is why they normally cause underboost, which logs would show HIGH WGDC for de-energized failed solenoids. If they somehow failed open, I would expect to see almost no WGDC value as the vacuum pump is directly closing the
actuator.

I would focus on the throttle closure because...
I believe that a faulty TMAP could send an incorrect PSI value to the computer signaling it to close the throttle prematurely, the sensor is temperature dependent, as is why people shoot meth before the sensor, and is why you may have issues after running a hard track lap, which you say is heat dependent.

Other things to consider would be the routing of the vacuum lines could cause bypassing of the solenoids if the wrong lines are "T'd" together.

(I am attaching the pictures I made because BMW uses vacuum , and not boost to control wastegates. Other turbo cars would overboost when solenoids fail.)

[///MPOSTER]

and for extra information on the solenoids. Also terry has stated that you cannot check the solenoids while not energized. The operation is to have 100% and then check the leak down of them. So unplugged and checking them in a sideways position or shaking them probably won't be a good way to verify.

[expressfish]

great post !

[sharkatron]

@///MPOSTER thanks so much for the information - if I could rep I would!

With regards to the vacuum lines - I made sure they were reattached into the same connections on the solenoids when I changed the pair over. Will check again to confirm - but if they were t'ed incorrectly, wouldn't it cause major problems? I read a thread where bypassing the solenoids is a very bad idea which could result in blown turbos?

For the sake of a couple of hundred bucks, I think I will get new TMAP sensors (same part numbers on the chargepipe and manifold right?). Can't hurt. Only thing is, how often do these fail? I have never read of them failing and causing overboost issues.

Also, not sure how important this information is, and whether it is even related (hoping it is so I can kill 2 birds with one stone), just prior to the overboost codes coming up on the dash, I have noticed a loss in power up the top end. When I plug the logs into a program such as VirtualDyno, it shows my butt dyno to be correct - I am down on power once things start getting hot. Think it is all related?? It just hit me - I guess it's the throttle closures...

[///MPOSTER]

You're welcome.

I just mentioned the vacuum lines for potential issues because "troubleshooting 101" in my brain would tell me that anytime something changes, it needs to be verified , otherwise it could lead to a cascading issue of problems not associated with the original issue. You verified you connected correctly so we can eliminate that road.

The Tmap is what I think it is based on the logs. Since every car is different , I couldn't say how often they fail. Some people experience bucking at slow rolling traffic like they are pushing gas and immediately getting off. Like " on off on off on off" until it somehow corrects itself and goes smooth. Some people have had issues where the car stumbles at idle even after walnut blasting , new injectors, plugs, coils. It would also oscillate at WOT and at a stop light the RPMs bounce up. Cleaning them resulted in a few thousand miles of trouble free driving but after it was oil covered, it came back. The OP of that ended up replacing the sensors. Another person stated “ I would plant my foot (not using kickdown) the revs would rise to about 2500k and around that mark I would feel a short hesitantancy. Its like the car doesnt know what to do”. Another person “Great news from me too. My sensors looked like that but more-so. The car is running perfectly now! Thrashed her last night. Just fired it up and purrrrfect idle. Guess there is something to be said for dirty MAP sensors then, even if they don't look too bad. On my RR prints it never looked as smooth as it should, even with smoothing on. Terry at BMS suggested it was throttle plate manipulation by the DME to fine control the boost. So this all makes sense really. Wish I had done the obvious earlier!”

As for your butt dyno, I think you are right about it not feeling powerful up top. If the throttle closes whether you or the DME does it, you will feel less power. It’s just that you are mashing the pedal and the DME is not doing what you are telling it to do.

On another note, I hate replacing things for the sake of replacing things, so that is why I suggested cleaning them with MAF/MAP cleaner sold in a spray can. I wouldn’t trust brake cleaner or other detergents/solvents as there are posts on issues arising with that. If it gets better for a few thousand miles, then you at least know it was that issue. On the other hand, if the sensor is already working outside of its tolerance (broken) then cleaning it will not do anything to help it, but it’s worth the $5 try. Best of luck to you , I hope you can get it up and running correctly!

[sharkatron]

Thanks ///MPOSTER for your contribution and input. I will definitely report back regardless of whether the issue is fixed or not. At least now I'm not so much fumbling around in the dark anymore!

[giovannm]

Hi sharkatron, did you understand and solve the issue? I had the same problem last week; I'am Italian owner of Z4 35i with DP and metal kat supersprint and COBB stage 2 sport tuned. First time on track (Vallelunga in Rome), and after 15 minutes of hard pulling pop up the error 3100 30FE. Consider that in Vallelunga the throttle is full open by 70/80%. After turn off the car and some minutes of coll down the car works normally, and no problem anymore in the daily driving. I also believe that are not specific issue, but something that is temperature sensitive. But I would like to know what! I hope someone could help

[sharkatron]

Hi sharkatron, did you understand and solve the issue? I had the same problem last week; I'am Italian owner of Z4 35i with DP and metal kat supersprint and COBB stage 2 sport tuned. First time on track (Vallelunga in Rome), and after 15 minutes of hard pulling pop up the error 3100 30FE. Consider that in Vallelunga the throttle is full open by 70/80%. After turn off the car and some minutes of coll down the car works normally, and no problem anymore in the daily driving. I also believe that are not specific issue, but something that is temperature sensitive. But I would like to know what! I hope someone could help

A few things I have read that may solve your issue include:

1: Ensuring all your boost/vacuum lines are intact with no cracks. I would personally just change them all as they are prone to cracking and causing boost issues. Any cracks or failing lines are supposed to result in underboost codes (30FF) but some individuals claim it has solved their overboost issues.

2: Ensuring your boost solenoids are in good working order. As ///MPOSTER has mentioned, once again these are usually the cause of underboost. But, as I have also mentioned in this thread, some individuals have claimed to have solved their overboost issues but swapping out faulty solenoids.

3: As ///MPOSTER has kindly explained, it might also be your TMAP sensors - check for the one on the manifold, and the one on the chargepipe. Read his explanation above as to why it may be the TMAP sensors. They have slightly different part numbers - the last digit differs by 1.

4: Your wastegates might be binding. Once again, this usually causes underboost. But hey, just like the above possibilities, some individuals have mentioned that by oiling their wastegates, it fixes the problem - momentarily until the heat burns the oil off and the seizing starts again. However, you should also do some logging as some parameters are able to log your banks for your turbos. If they are aligned, don't think it's a seizing problem. If they are out of alignment, then maybe your turbos need replacing.

I have attempted 1 and 2 with no success. Have just ordered TMAP sensors and waiting for them to arrive. I'm doing all the relatively cheap stuff first. Hopefully it's the TMAP sensors. Let us know how you go.

[expressfish]

following...

[sharkatron]

So I finally got my TMAP sensors and had them both replaced with the brand new ones. Took it out for a spin and noticed that not much has changed. I haven't taken any logs, but I can recall highest boost on a run via the P3 vent gauge. I've run a line to tap boost so I know it's fairly accurate. Anyway, first run was about 17.5psi. Next 4-5 were around 18 - 18.1psi. About the 7th run it went to 18.7psi, and then the 8th 18.8psi. I get the feeling if I stayed out there for longer with more runs, it would eventually trip the overboost code.

Anyone know by any chance what the upper boost limit is of a Cobb Protuned map? That's what I'm running.

[///MPOSTER]

Thanks for the update. I wish you were JB4 so I could help you adjust it. Hopefully someone with a Cobb background can help you. Did you also try the stock map now that the new sensors are installed? You may also want to do an adaptation reset with all the new stuff you have changed and the colder weather.

[sharkatron]

I did reset some adaptations... but which ones were you specifically thinking of?

Just thinking out loud, but how would me using JB4 make it any different?

Time to change cars me thinks

[///MPOSTER]

Just the throttle adaptation, as the AFRs/Fuel shouldn't be of concern.

As for the JB4, I had helped someone else already with overboost by lowering the wastegate adaptation called FF ( feed forward) which is a global scaling of wastegate adaptation process. This method could lower the overall curve so it doesn't overshoot, therefore not rely on PID try to correct it. Or if you looked at your logs, then you could essentially find the area of overshoot and bring wastegate adaptation a lot lower during that point by using Duty Bias by RPM so that it doesn't overshoot. You can do the same with COBB but I have no idea on that process since I have not used it.

I remember you saying the tune is locked so you can't adjust it, but you could always try another back end flash and see what it does for you. But if you are still having issues on stock map after all that you have changed, then you would just be using a tune to remedy an underlying issue. Its fine for the short term but long term you need to find out what it is.

[giovannm]

Just the throttle adaptation, as the AFRs/Fuel shouldn't be of concern.

As for the JB4, I had helped someone else already with overboost by lowering the wastegate adaptation called FF ( feed forward) which is a global scaling of wastegate adaptation process. This method could lower the overall curve so it doesn't overshoot, therefore not rely on PID try to correct it. Or if you looked at your logs, then you could essentially find the area of overshoot and bring wastegate adaptation a lot lower during that point by using Duty Bias by RPM so that it doesn't overshoot. You can do the same with COBB but I have no idea on that process since I have not used it.

I remember you saying the tune is locked so you can't adjust it, but you could always try another back end flash and see what it does for you. But if you are still having issues on stock map after all that you have changed, then you would just be using a tune to remedy an underlying issue. Its fine for the short term but long term you need to find out what it is.

I don't think the issue is "COBB driven" because it's happened only after 20 minutes of hard pushing in the track. I believe this is due to hot that influence something in the boost, but I don't know what

[///MPOSTER]

I don't think the issue is "COBB driven" because it's happened only after 20 minutes of hard pushing in the track. I believe this is due to hot that influence something in the boost, but I don't know what

I understand that it's not Cobb driven, but you can tune out an overboost issue just as easily as a novice accidentally creates an underboost issue by changing parameters. By correcting the curve before it gets to the point where it signals the overboost condition. Trying another tune map that is modifiable is all I am suggesting.

[sharkatron]

@///MPOSTER just wondering if the position of the wastegate actuator reflects the value shown in banks? Or is it a value that is to be applied to the WGs based on all other factors? As in does banks value determine the position of the WGs? Or does the actual position of the WGs determine the banks values?

[///MPOSTER]

The value is the PWM value to the solenoids to allow vacuum to pass and the PID is the correction value once it senses the actual boost. Too low PID it overshoots, too high it oscillates trying to correct .
If the question is that it says bank 1, I think it doesn't matter because it's tied by T and both actuator will see the same vacuum despite if one boost solenoid is not allowing vacuum. There is no sensor in the exhaust to measure clearance of the wastegate flapper.

Did anyone before you owned the car adjust the actuator arms? Specifically the rear to get rid of the rattle?

[sharkatron]

Ahh I see... I get that the values should be the same as the actuators are T'ed together. So despite the values showing what should be happening, it does not necessarily reflect what is actually happening to the WGs? So there is potential that the problem could still be a seizing WG arm?

I am the sole owner of the car - bought new in 2009. Have not touched the turbos at all since owning it. I do have downpipes installed - shop verified with me they ensured the arms were free-moving after installation and not knocking on any installed bits. Have not noticed any rattle - hence have not touched the actuator arms.