Boost/Vacuum Leak? Video and Logs Inside..

[TechE]

Had a new development yesterday. When I let off, I get turbo sound almost similar to a BOV.. It's a bit it difficult to hear in the video. Seems I've lost some boost as well. I also have a slightly erratic idle with uneasy starts from a stop. I'll be taking a look under the hood this weekend hopefully. 3 short logs of incremental throttle increase below.

Logs

I'll clean the dust soon. Been busy

[annalisa_ferri]

Difficult to judge from the video, but if you have erratic response to gas pedal, you may be willing to look at the vacuum canisters: they are prone to cracking especially near the inlets/outlets: double check that the hoses are firmly in place at both ends (items #1 in the link):

http://www.realoem.com/bmw/enUS/show...diagId=11_3975

Also try to follow the vacuum hoses as much as you can into the engine bay, sometimes you can do it only without seeing but your hand can feel if the connections are ok. Don't fear to break anything and apply quite some pressure when pushing and pulling those hoses.

[YearOneOne]

Originally Posted by annalisa_ferri

Difficult to judge from the video, but if you have erratic response to gas pedal, you may be willing to look at the vacuum canisters: they are prone to cracking especially near the inlets/outlets: double check that the hoses are firmly in place at both ends (items #1 in the link):

http://www.realoem.com/bmw/enUS/show...diagId=11_3975

Also try to follow the vacuum hoses as much as you can into the engine bay, sometimes you can do it only without seeing but your hand can feel if the connections are ok. Don't fear to break anything and apply quite some pressure when pushing and pulling those hoses.

We don't have those on n55

[YearOneOne]

The sound is probably your wastegate. A couple questions though was the last log of your idle?
Can you do a log in 3rd gear from 2500 to redline have you replaced your plugs and coils? And have you changed your dv?

[TechE]

I have coils and plugs on hand actually, that was my next to-do. I was experiencing very slight hesitations intermittently during slow acceleration, especially noticeable uphill. I chalked that up to being small misfires after some research, and decided to do the above.

No DV work. Been running FBO with MHD 2+ for under 1k miles. It was on the list of potential purchases.

I didn't have any idle logs. Only slow from a start, medium, and fast acceleration. I can try to get a 2,500 to redline in a bit.

[TechE]

Slow starts from a stop with idle and 3rd gear pull logs.

Here's what I had code wise. Not sure what's up with the VIN, I assume MHD has something to do with it. Cleared them so we'll see what pops back up..

[HyeWarrior]

Do you have an aftermarket intake installed?

[YearOneOne]

I would definitely change those but there has to be a leaks which could very well amount to the dv which from studies does not hold up the stress. In on the stock dv also and mine leaks also but check all your connections too

[TechE]

Originally Posted by HyeWarrior

Do you have an aftermarket intake installed?

Negative. Did a quick check of connections since it's an easy kill. May end up pulling it apart though to look for cracks underneath.

I'm suspicious of the DV as well, but hoping it's the hose from the turbo outlet to FMIC inlet.. again.

[YearOneOne]

Originally Posted by E.Usaf

Negative. Did a quick check of connections since it's an easy kill. May end up pulling it apart though to look for cracks underneath.

I'm suspicious of the DV as well, but hoping it's the hose from the turbo outlet to FMIC inlet.. again.

Hopefully. Good luck

[TechE]

After a bit under the hood and car I made a little progress. Pulls are noticeably quicker. I ended up tightening the hose between the turbo and fmic, again. As seen below, I also found a bad o-ring in the ccv. If anyone can tell me what size it is it'd help me out. I've only found the hose itself [p/n 11127590163] so far for $30.



I'm pretty certain the DV isn't holding like it should be. I still get excess turbo noise while spooling and after letting off. I have a DV+ in my cart right now, so that's the next fun installment.

I also yanked on my wastegate actuator arm and it was pretty easy to move. I could hear the diaphragm(?) but it didn't seem like there was a good seal. Can anyone shed some experience with that? Could it be faulty or should I monkey around with it and see if it needs to be adjusted?

Additionally, I'm not sure how I feel about the connections on the turbo outlet and intake manifold. They wiggle too much for comfort, even though the first is stock, and my charge pipe uses the stock clip. I assume everyone else's is similar?..

[mfindigital]

Astonishing how many parts on this car don't hold up. Sort of depressing until you drive it again.

[TechE]

Small update. Plugs and coils were replaced, MAF sensor was cleaned. I noticed an improvement in response but still have bogging in 1st/reverse when cold. Temporary rise in RPMs to around 1100 when idle is also still happening but doesn't seem as severe. I'm not sure if this is something I'll be able to fix until there is a new map..

DV+ install this weekend hopefully.

[TechE]

It's fixed. No more rough idle. No more excess turbo noise. All the psi.

And it wasn't the diverter valve. I didn't end up installing it. I'm going to do a full coolant flush and pump replacement soon and I'll throw it on then.

Anyways, a word to the wise, make sure you look over all of your components thoroughly when troubleshooting. The screw in the meth bung on the bottom of my charge pipe decided at some point it didn't want to stay in anymore, so, that's what I've been dealing with for over a month now. I took most of my intake system apart before, even disconnected the CP to inspect the o-ring and make sure it was seated properly on the manifold, but didn't bother looking on the bottom of it.

Both screws are now taped up and tight to ensure it doesn't happen again. In the mean time, my boost is back

[HyeWarrior]

I literally had the same exact problem as you last Thursday lol. Over a dumb bolt

[Soterios]

Originally Posted by E.Usaf

It's fixed. No more rough idle. No more excess turbo noise. All the psi.

And it wasn't the diverter valve. I didn't end up installing it. I'm going to do a full coolant flush and pump replacement soon and I'll throw it on then.

Anyways, a word to the wise, make sure you look over all of your components thoroughly when troubleshooting. The screw in the meth bung on the bottom of my charge pipe decided at some point it didn't want to stay in anymore, so, that's what I've been dealing with for over a month now. I took most of my intake system apart before, even disconnected the CP to inspect the o-ring and make sure it was seated properly on the manifold, but didn't bother looking on the bottom of it.

Both screws are now taped up and tight to ensure it doesn't happen again. In the mean time, my boost is back

That is frustrating and hilarious. I'm going to throw a clamp over my meth bung screws now. Thank you.