[Ditcher]

I posted this on the 1er side with no luck so I'll try here. Maybe more traffic on the E9x side.

09 135i fbo, rebuilt turbos mhd ots tune.

I started noticing exhaust note change not long after installing turbos. maybe a few days of driving when I noticed it. Read that the wgdc would cause that so I monitored it and every once in a while i hear the exhaust and wgdc would go to 0. I changed the tune to stage 1 to see if that would do anything and still did it. I replaced the rear boost solenoid since I figured that be the first one to go bad. No change. It will go to 0 cruising, going up hill, coming to a light and a few sec after giving it throttle. Don't seem to matter if its cold or hot. Few seconds after starting and driving off or 20 minutes later. May happen once or may happen 7 times in a 30min drive. Haven't seen it do it at wot or hard accelerations. When it goes to 0 I can smash the peddle and let of real fast and it will jump up then go back to 0.

What are the odds the front boost solenoid is causing this?
Could this be a bad actuator? out of adjustment?
stuck actuator? This is driving me crazy.

[Saif2018]

Originally Posted by Ditcher

I posted this on the 1er side with no luck so I'll try here. Maybe more traffic on the E9x side.

09 135i fbo, rebuilt turbos mhd ots tune.

I started noticing exhaust note change not long after installing turbos. maybe a few days of driving when I noticed it. Read that the wgdc would cause that so I monitored it and every once in a while i hear the exhaust and wgdc would go to 0. I changed the tune to stage 1 to see if that would do anything and still did it. I replaced the rear boost solenoid since I figured that be the first one to go bad. No change. It will go to 0 cruising, going up hill, coming to a light and a few sec after giving it throttle. Don't seem to matter if its cold or hot. Few seconds after starting and driving off or 20 minutes later. May happen once or may happen 7 times in a 30min drive. Haven't seen it do it at wot or hard accelerations. When it goes to 0 I can smash the peddle and let of real fast and it will jump up then go back to 0.

What are the odds the front boost solenoid is causing this?
Could this be a bad actuator? out of adjustment?
stuck actuator? This is driving me crazy.

Have you got any logs?

WOT logs,

So your saying its zero WGDC when idle or cruising, but it ramps up fine under WOT?

[Ditcher]

I do have a couple of logs. Few wot and a couple of when wg goes to zero. I just have to figure out how to post them.

But yes I will randomly get 0 wgdc any where from idle to cruise to some time light acceleration. Sometimes it will come back with little bit heavier acceleration and sometimes it comes back and goes away once you let off. Hasn't dropped to zero under heavy or wot. It's straight pipe so I know when it goes to zero. LOL gets loud and sounds like crap.
I messed with the rear actuator and it feels fine no binding and without taking off the DP seems to be close to rig. Front one is a little harder to tell.
I'm almost temped to route a vacuum gauge in the and see what it is doing.

[Dave92N54]

Google N54 CILC

[Ditcher]

Originally Posted by Dave92N54

Google N54 CILC

I read some on it. Some say its normal to go to 0 at cruise speed to adjust afr's. But mine does it more than just at cruise. I read someone talking about not having the rear 02 sensors would make the car run more checks making wgdc going to 0?

Might try a adaption reset a friend suggested.

[Dave92N54]

Hmm, interesting. Do you not have rear 02s? If not, put them in asap.

I would be more inclined to believe an adaptation reset will make it worse before it gets better. The CILC is part of the adaptation process, clear your adaptations and it will do it more in order to adapt. I have no real data for this but I can certainly say I notice it more after lambda adaptation resets, but could be worth a shot.

[Ditcher]

Ok I don't know why I thought the rear 02 were out but they are hooked up.
I don't know if this helps but when monitor lambda 1 and 2 when wgdc goes to 0 lambda doesn't change. They both fluctuate around 14.00 to little over 15.00.

[Ditcher]

So I did the adaption reset via protool. I didn't know mhd had it as well at the time.
I reset the car back to factory tune. Drove it a short distance and so far so good.
I'll leave it on factory tune for a few days and see how it acts.

[Ditcher]

Well it still doing the same thing. I didn't drive it much on stock tune but the few time it happen was mild compared to on mhd tune. I retuned the car on mhd 2+ and on the way home just before I got off the exit it went to 0. One those long exits. stayed at 0 for about 10-15 secs.
If I get a chance I'll do a leak test if I don't decide to do a ls swap. This would just odd if it was a normal function.

[Ditcher]

So I hooked up vacuum pump to the wastegate again but this time I decided to see if they would hold vacuum. Pumped both actuators (one at a time) to 10 inhg and after a few secs they bleed down to about 2-4 inhg. I still have the old wastegates so i checked them and they hold vacuum. I'm going to be mad if this has been my issue. lol

Edit:
I double checked them again and both front and rear actuator are bleeding down to 0 in about a min or less. The oem ones are holding rock solid. So can the front actuator be changed without removing the turbo?

[Ditcher]

Update.
I was about to mess with the actuators cause they had failed the leak check but something told me to check them again. Long story short my vacuum pump was faulty and I went and got a new one. Both actuators tested good.
I decided to check the BOV after checking a few other stuff. I pulled the BOV and found the Oring pinched. About 1/4 wasn't sealed. So I guess the person that had it before me didn't install it correctly. I have to get a new one but I made the old one work for now. Took the tial bov apart and cleaned the piston and lubed it up. I notice a little ware on one side. I'm thinking maybe the uneven pressure was pushing uneven on the piston and hanging up causing boost leak and wgdc going to 0. Drove it for 15 mins and so far so good. I'll report back either tomorrow or the next day if its fixed.

update: Did not fix issue. No surprise. I blocked off the vacuum line that ties both boost solenoid and went for a 40min drive and it wouldn't do it. So i'll have to wait until tomorrow to see if it will do it. Normally will do it in the morning.

[Ilma]

Been following your thread......so thanks for posting.

I have had a similar INTERMITTENT issue for a couple of years now where my WGDC would drop to 20% at idle.......whereas it normally sits at 60% at idle in order to keep the turbos spinning for spool when you step on the throttle.

I would get a loud exhaust tone and very bad turbo lag when accelerating from a stop or slow cruise.

I called my mechanic after reading your thread and mentioned the actuators leaking but he said that if you had a leaking diaphram in the actuator it would leak all the time.

Also if there is a vacuum leak in the wastegate control system, your duty cycle would skyrocket trying to achieve the boost target when it cannot do so because a leak is not pulling the wastegates closed.

You originally asked if the problem could be the boost solenoid pressure controller and my mechanic mentioned the same thing.

I didn't see that you tried replacing those yet.......but please keep us posted as to your findings.

[Ditcher]

Originally Posted by Ilma

Been following your thread......so thanks for posting.

I have had a similar INTERMITTENT issue for a couple of years now where my WGDC would drop to 20% at idle.......whereas it normally sits at 60% at idle in order to keep the turbos spinning for spool when you step on the throttle.

I would get a loud exhaust tone and very bad turbo lag when accelerating from a stop or slow cruise.

I called my mechanic after reading your thread and mentioned the actuators leaking but he said that if you had a leaking diaphram in the actuator it would leak all the time.

Also if there is a vacuum leak in the wastegate control system, your duty cycle would skyrocket trying to achieve the boost target when it cannot do so because a leak is not pulling the wastegates closed.

You originally asked if the problem could be the boost solenoid pressure controller and my mechanic mentioned the same thing.

I didn't see that you tried replacing those yet.......but please keep us posted as to your findings.

Not sure if you read my last update or not but the leaking actuator turned out to be my vacuum pump was intermittently going bad on me. I picked up a new vacuum gauge and it held pressure. I was thinking that at first as well. Wouldn't do it all the time? But Have worked on aircraft you see some weird stuff. BTW I did replace the rear boost solenoid not long ago. Friend just sent me a fairly new one cause he didn't need it anymore. So I will be replacing the front one here soon.
I had blocked the line that tied both boost solenoids to gather to try to rule out a solenoid issue, one side randomly losing vacuum or stuck WG.
Well They both still went to 0. Last time lasted longer then normal and stayed at 0 even after coming to a stop. So I started thinking maybe it something that is throwing the car into a soft limb mode with no codes. Again anything is possible with these cars. I pulled the Vano check valves last night to check them. I also wanted to check them cause the car will buck/surge and have rough cold start sometimes and its one the things that can cause it. Check valves were clean and not coked up. Cleaned them up a little bit. I still need to reinstall them.
I did clean the vanos awhile back but I went ahead and bought new ones. Figured for 131.00 bucks why not. I'm hoping this might tell me something.
Once I figure something out. I'll post it.

[Ditcher]

So What I'm thinking is something is intermittently going bad causing it to go to 0 randomly.
Give the way the car runs sometimes it could be a vanos issue. You might ask well why not injectors or coils a plugs that can do that as well. Well the injectors or new index 12's. Yes its not unheard of getting a bad one. But since they are new I'm ruling them out.
Plugs and coil are pretty new. I ruled the check valves out yesterday or least hope I did. LOL Parts wont be in until next week unfortunately. So the BMW is going to do what it dose best. Sit in the garage with hood up. LOL JK little bimmer joke?
If anyone else has any idea or think i'm just crazy please let me know down below.

[Saif2018]

Originally Posted by Ditcher

So What I'm thinking is something is intermittently going bad causing it to go to 0 randomly.
Give the way the car runs sometimes it could be a vanos issue. You might ask well why not injectors or coils a plugs that can do that as well. Well the injectors or new index 12's. Yes its not unheard of getting a bad one. But since they are new I'm ruling them out.
Plugs and coil are pretty new. I ruled the check valves out yesterday or least hope I did. LOL Parts wont be in until next week unfortunately. So the BMW is going to do what it dose best. Sit in the garage with hood up. LOL JK little bimmer joke?
If anyone else has any idea or think i'm just crazy please let me know down below.

Vanos Solenoids don't control boost, doubt it has any effect on WGDC issue

Faulty Boost solenoids, probably

[studio54]

Originally Posted by Ditcher

I read some on it. Some say its normal to go to 0 at cruise speed to adjust afr's. But mine does it more than just at cruise. I read someone talking about not having the rear 02 sensors would make the car run more checks making wgdc going to 0?

Might try a adaption reset a friend suggested.

When i got some CILCs, mine did more than just at cruise too. I had to throttle way more or WOT to get out of WGDC 0. Duration was random, but it wasn't excessing an amount of time of like 30 seconds to 1 minute.

I don't think it could be boost solenoids since it's not sensors, it's the DME that command the WGDC value anyway, so if you log WGDC, you are not logging the actual WGDC position, you are logging what the DME is commanding, so a part a CILC, i don't know what it could be.

Found on another forum :

"You need at least one secondary, and if not running two, you must enable single rear o2 toggles. This is probably part of your problem, as it's continually running checks to see what is going on and it swings lambda super lean <--> super rich for the test. Your main lambda are probably mis calibrated now as well."

Maybe a problem with o2 sensors.

[Ditcher]

Originally Posted by studio54

When i got some CILCs, mine did more than just at cruise too. I had to throttle way more or WOT to get out of WGDC 0. Duration was random, but it wasn't excessing an amount of time of like 30 seconds to 1 minute.

I don't think it could be boost solenoids since it's not sensors, it's the DME that command the WGDC value anyway, so if you log WGDC, you are not logging the actual WGDC position, you are logging what the DME is commanding, so a part a CILC, i don't know what it could be.

Found on another forum :

"You need at least one secondary, and if not running two, you must enable single rear o2 toggles. This is probably part of your problem, as it's continually running checks to see what is going on and it swings lambda super lean <--> super rich for the test. Your main lambda are probably mis calibrated now as well."

Maybe a problem with o2 sensors.

Yeah I didn't think it was boost solenoids either. I also think the dme is commanding them closed. Just need to find out why.
So update time!
Did a lot of work over the last few days.
I installed a newish front boost solenoid since it was free and only a few months old. I replaced the 02 sensor with newish ones a friend gave me since he upgraded his for the single turbo. Also only a few month old. Also found the vent tube to the valve cover a little lose and shoved it all the way in.
Went for a test drive and she's still doing it.

Got the vanos in and installed both and replaced the bosh plugs with nkg 1 step colder and gaped to .22. Reset adaptions. Went for test drive.
Car did not run well. It bucked quite a bit on test drive and on the way back to the house when oil temp was up to operational temp. Check engine light cam on and dme pulled boost 0 wgdc. The code was for intake vanos.
I reset the code and went out one more time. This time after get oil temp back up I got the exhaust vanos and no boost. cycled key and drove home and got the intake vanos code back. So I have both intake and exhaust vanos. But hey wgdc never went to 0 until I got the vanos code. LOL
Now I got to figure this issue out. Before anyone ask. It has fairly new oil liquid moly 5w40 and mann filter. Oil cap stem and cage is there along with oring on the bottom of the stem. What are the odds that both vanos (vaico brand) are bad from stock. Old one never through a code. Also both vanos check valves have been cleaned even though they were pretty much clean already.

[studio54]

Originally Posted by Ditcher

Yeah I didn't think it was boost solenoids either. I also think the dme is commanding them closed. Just need to find out why.
So update time!
Did a lot of work over the last few days.
I installed a newish front boost solenoid since it was free and only a few months old. I replaced the 02 sensor with newish ones a friend gave me since he upgraded his for the single turbo. Also only a few month old. Also found the vent tube to the valve cover a little lose and shoved it all the way in.
Went for a test drive and she's still doing it.

Got the vanos in and installed both and replaced the bosh plugs with nkg 1 step colder and gaped to .22. Reset adaptions. Went for test drive.
Car did not run well. It bucked quite a bit on test drive and on the way back to the house when oil temp was up to operational temp. Check engine light cam on and dme pulled boost 0 wgdc. The code was for intake vanos.
I reset the code and went out one more time. This time after get oil temp back up I got the exhaust vanos and no boost. cycled key and drove home and got the intake vanos code back. So I have both intake and exhaust vanos. But hey wgdc never went to 0 until I got the vanos code. LOL
Now I got to figure this issue out. Before anyone ask. It has fairly new oil liquid moly 5w40 and mann filter. Oil cap stem and cage is there along with oring on the bottom of the stem. What are the odds that both vanos (vaico brand) are bad from stock. Old one never through a code. Also both vanos check valves have been cleaned even though they were pretty much clean already.

When the DME is asking WGDC is asking 0, it's not asking them closed, but full opened. That's why it sounds louder. Closed WGDC means for spool and during WOT. Are you confident about all your o2 sensors ?

[Ditcher]

The front ones I am but not the rear. I know that 0 means open. Maybe I'll pull the bank rear one and check it. When I bought the car it had a leaking fwd turbo. Maybe its full of carbon. Btw there are 2 02 on the back.
I ordered a new vanos (Gates) I hear the ones I order are a hit or miss. We will see.

[Saif2018]

Originally Posted by Ditcher

I do have a couple of logs. Few wot and a couple of when wg goes to zero. I just have to figure out how to post them.

But yes I will randomly get 0 wgdc any where from idle to cruise to some time light acceleration. Sometimes it will come back with little bit heavier acceleration and sometimes it comes back and goes away once you let off. Hasn't dropped to zero under heavy or wot. It's straight pipe so I know when it goes to zero. LOL gets loud and sounds like crap.
I messed with the rear actuator and it feels fine no binding and without taking off the DP seems to be close to rig. Front one is a little harder to tell.
I'm almost temped to route a vacuum gauge in the and see what it is doing.

Use Datazap.me, post logs on there its free

[studio54]

Originally Posted by Ditcher

The front ones I am but not the rear. I know that 0 means open. Maybe I'll pull the bank rear one and check it. When I bought the car it had a leaking fwd turbo. Maybe its full of carbon. Btw there are 2 02 on the back.
I ordered a new vanos (Gates) I hear the ones I order are a hit or miss. We will see.

Yep, 2 front o2 and 2 rear o2.

The guy on the other forum said that the lack of any rear sensor will trigger a lot of CILC checks. Hope that helps !

Let us know when you figured that.

[Dave92N54]

Any update OP? I just experienced this today, twice on my way home. It pegged to 0, and wouldn't change. I popped it in neutral and I watched it spike to 80% for like .2s and then back to 0. I revved it a few times and nothing. I was at a light at this point so when I started moving again after a few seconds it came back to normal values. Then maybe 5 minutes later it did it again.