[Mark M]

Upon startup the Actuator rod should retract which opens the changeover valve directing exhaust gases into the small turbo. Upon engine shutdown, the actuator rod does not release until 30 to 50 seconds after engine shutdown. Some say ~23 threads is the sweet spot on the rod for the mounting nuts. I can not confirm this.

I too am chasing intermittent laggy feel at the low end. Some days the car is amazingly responsive and barely sips fuel....other days it feels laggy and fuel consumption is increased along with a slightly more audible howl from the airbox on hard acceleration.

[OmahaDZL]

Originally Posted by Mark M

Upon startup the Actuator rod should retract which opens the changeover valve directing exhaust gases into the small turbo. Upon engine shutdown, the actuator rod does not release until 30 to 50 seconds after engine shutdown. Some say ~23 threads is the sweet spot on the rod for the mounting nuts. I can not confirm this.

I too am chasing intermittent laggy feel at the low end. Some days the car is amazingly responsive and barely sips fuel....other days it feels laggy and fuel consumption is increased along with a slightly more audible howl from the airbox on hard acceleration.

Hey Mark,
As you probably have seen Ive got much the same issues. Currently mine is set to 16 threads to the end of the rod...which is what it was factory (with OEM turbos) because my mechanic painted the rod before removal.

Anyway, when i got in there the other day to move the adjustment, the vacuum hadnt released at all....until i wiggled it around a bit after loosening the nut... Im wondering if my vacuum control of that thing is faulty...

Thoughts? Yohz, any way to test that by swapping hoses somewhere Im kinda waiting to go through Rheingold and run through a test that it hast to have in there somewhere about a procedure to check all those. Anyone have input on that?

[Yozh]

Originally Posted by OmahaDZL

Hey Mark,
As you probably have seen Ive got much the same issues. Currently mine is set to 16 threads to the end of the rod...which is what it was factory (with OEM turbos) because my mechanic painted the rod before removal.

Anyway, when i got in there the other day to move the adjustment, the vacuum hadnt released at all....until i wiggled it around a bit after loosening the nut... Im wondering if my vacuum control of that thing is faulty...

Thoughts? Yohz, any way to test that by swapping hoses somewhere Im kinda waiting to go through Rheingold and run through a test that it hast to have in there somewhere about a procedure to check all those. Anyone have input on that?

OmahaDZL, why don't you test your turbine switchover vacuum actuator by use of a simple hand pump and see if it activates, hold vacuum and releases easily. Simple to do and to assure that mechanically, you are covered.

[OmahaDZL]

Originally Posted by Yozh

OmahaDZL, why don't you test your turbine switchover vacuum actuator by use of a simple hand pump and see if it activates, hold vacuum and releases easily. Simple to do and to assure that mechanically, you are covered.

I can guarantee it doesnt release easily thats for sure....hours after shutting the car off....it hadnt released at all.

[Yozh]

Lets test your vacuum actuator and then your pressure converter and then your boost sensor. That should get you on a right path to solving this.

[civilator]

Originally Posted by Yozh

Lets test your vacuum actuator and then your pressure converter and then your boost sensor. That should get you on a right path to solving this.

hi Yozh,
looks like each of us go through the same issues at one point or another. I am currently having small turbo boost issue.

I printed out your write-up on testing of the vacuum system. Planning to follow it step by step once the parts arrive.

from the time you wrote that procedure to today, are there any other suggestions (I will start with the one above with the hand pump and go from there)?

also, I have seen remarks about testing the actuators with diagnostic tools.
I have a laptop but dont know which version of ISTA to install and what procedure to use to test the system. is there a thread or an article about this ?

[Hoooper]

I had a huge hole in a vacuum line just off the vacuum manifold but didnt notice a loss of power or anything, or maybe I still have another vacuum loss somewhere else so it just didnt make a difference when I replaced that line? I dont quite understand how its possible I didnt notice power loss though.

[Yozh]

Strange.

[335dsleeper]

I had a similar experience with my X5. Completely torn hose. No change once fixed.

Originally Posted by Hoooper

I had a huge hole in a vacuum line just off the vacuum manifold but didnt notice a loss of power or anything, or maybe I still have another vacuum loss somewhere else so it just didnt make a difference when I replaced that line? I dont quite understand how its possible I didnt notice power loss though.

[da_trem]

I'm also having that issue from time to time, no boost at all below 3000rpms. Really feels like its waiting on vacuum(lag) to build up for the pressure converter. I play with the throttle on and off and suddenly boost reappears..

All vac lines are new, boost converters are also new, and both turbo are new. Tested vac on the switchover actuator and its ok.

[Stasun]

Originally Posted by da_trem

I'm also having that issue from time to time, no boost at all below 3000rpms. Really feels like its waiting on vacuum(lag) to build up for the pressure converter. I play with the throttle on and off and suddenly boost reappears..

All vac lines are new, boost converters are also new, and both turbo are new. Tested vac on the switchover actuator and its ok.

How did you solved it?

[335dMERZO]

Originally Posted by kiel_dafo_kenyg_as

In the end it was the pressure converter for the EGR valve that was introducing air into the vacuum.

Martin,
if you don't have a vacuum tester you can pull the hose joints off and suck on them (no pun intended) or blow (eventually cigarette smoke) into the system and hear or see where it comes out. You can also feel if vacuum is there when you put your finger tip on the hose ending (engine running).
I was able to move the turbine changeover actuator rod with the power of my lungs

I pulled the big hose off of the Pierburg vacuum pump and tested for suction on the pump nipple. You may check this too.

Phew, this nightmare has come to an end for me

Good luck!

I know this post is a bit older, but I am having same issue. Recently had to change egr cooler. I am having code for boost leak. I’m half engining and have to floor it to get up to speed. I have narrowed it down to changing the vacuum control valve or pressure converter. Can you explain where both of these are located in relation to the small turbo?
Thank you

[lnxguy]

Originally Posted by 335dMERZO

I know this post is a bit older, but I am having same issue. Recently had to change egr cooler. I am having code for boost leak. I’m half engining and have to floor it to get up to speed. I have narrowed it down to changing the vacuum control valve or pressure converter. Can you explain where both of these are located in relation to the small turbo?
Thank you

If you're having a code for a boost leak, have you actually checked for a boost leak? Both PC valves and the EV valve are on the passenger side of the engine. What code specifically are you getting?

[335dMERZO]

The code is p0299. I changed all vacuum lines. Took to mechanic and they couldn’t figure it out but I think it’s between pressure converter or vacuum control valve based on my research. There are no leaks. Mechanic stated they had limited information and did not know how valve is supposed to operate. They suggested control solenoid or problem with small turbo itself. I truly do not believe it is the turbo itself. I only have 85k miles. Can I get some guidance as to changing the parts mentioned above?
Thank you!
I’m not sure if it is related, but this code popped up the day after changing my EGR cooler.

[lnxguy]

So that's an underboost code. You've got 2 Pressure Convertors and 1 electronic valve which controls a bunch of stuff on the engine. Pressure convertors control the wastegate and turbine switchover, EV controls compressor bypass. If you haven't already, replace all 3.

I would suggest watching the Projekt Seven videos on Youtube. He does a great job at explaining how to test each one and also where they are located in order for you to replace them yourself. Not a very hard job once you get all the crap out of the way.

[335dMERZO]

[QUOTE=lnxguy;27998010]So that's an underboost code. You've got 2 Pressure Convertors and 1 electronic valve which controls a bunch of stuff on the engine. Pressure convertors control the wastegate and turbine switchover, EV controls compressor bypass. If you haven't already, replace all 3.

I would suggest watching the Projekt Seven videos on Youtube. He does a great job at explaining how to test each one and also where they are located in order for you to replace them yourself. Not a very hard job once you get all the crap out of the way.[/QUOTE

I’m at a total loss. I’m not sure what to do. I really don’t think it’s my turbo. Do you know of anyone in Fresno California who works on bmw diesal?? I want it fixed so bad so I can sell it. I’m over it.

[335dMERZO]

[QUOTE=335dMERZO;28030502]

Originally Posted by lnxguy

So that's an underboost code. You've got 2 Pressure Convertors and 1 electronic valve which controls a bunch of stuff on the engine. Pressure convertors control the wastegate and turbine switchover, EV controls compressor bypass. If you haven't already, replace all 3.

I would suggest watching the Projekt Seven videos on Youtube. He does a great job at explaining how to test each one and also where they are located in order for you to replace them yourself. Not a very hard job once you get all the crap out of the way.[/QUOTE

I’m at a total loss. I’m not sure what to do. I really don’t think it’s my turbo. Do you know of anyone in Fresno California who works on bmw diesal?? I want it fixed so bad so I can sell it. I’m over it.

Would anyone be willing to discuss further with me over the phone? I would love to solve this on my 335d. I don’t want to fully give up.
(559)770-9891

[maryjane]

PM me for number i can help you with some tests to help determine issue.