35d Pressure Converters w/ 73k - Replace?
 

Hey guys,
I've gone into the deep end with my 35d with replacing the vacuum lines, doing a thorough cleaning of the throttle body, EGR valve, intake manifold and swirl flaps. While I'm still under warranty I decided I just wanted to take the initiative and get this stuff done as preventative and keep the 35d running as best it can. Anyways, getting to all the vacuum lines by the pressure converters is beyond stupid. Its extremely tight and I'm to the point where I can either leave the current converters in and hook everything up or replace them at my cost as a preventative measure......keeping in mind that I'm still under warranty for another 7 months. Replacing them would require further dis-assembly which could be a big pain given where the last few bolts are.

Anyways, curious to hear what you guys think...

I had my manifold off earlier this year, I'm at 140k km (about 87k miles), and my swirl flaps were clean. See http://www.xoutpost.com/1039112-post5.html
Assuming that yours are the same with no CBU, I would say its not a concern.

Swirl flaps were ok. Same with the manifold.

Here's what they looked like upon removal.
http://i145.photobucket.com/albums/r...psrjzfvfzy.jpg

http://i145.photobucket.com/albums/r...pszchpfdvg.jpg

I would say those are relatively clean considering what I have seen from the 335d

Yeah, pressure converters are a b!tch to get to, but I was able to replace individual ones(it was for testing, mine are perfectly fine). Raymond(the Norwegian diesel tuner)mentioned that they were replacing them all the time when he was working at a BMW dealer a few years ago, but I didnt hear about any failures here. It is pretty much your decision to replace them all or not. I wouldnt replace them at this mileage.

Honestly it's nearly impossible to get access to the converters on my 2011 35d. I'd love to see what the shop manual says for replacement but I haven't been able to find anything online. I'm also replacing the red vacuum hose but that goes below the back pressure converter. I'm tempted to just cut it and add a connector to extend it with new hose as far back as I can because it's that hard to get to.

I have been able to remove one of the converters with long socket and electric ratchet.
I recommend you to extend the blue and red hoses as they may be quite stretched even when new.

Must be the front pressure converter you got to as I could remove that one as you stated. As for the vacuum hoses I've done just that. Every blue and black hose has been replaced and as for the red I'll likely cut the original towards the back and add a connector to extend new hose towards the front. Actually I think I might have just two black hoses I can't replace due to their location and risk of breaking a sensor.

Brining up an old thread - not alot of info on pressure converters for e70.

Has anyone gotten around to replacing their converters yet?

I am replacing both pressure converters at 110,000 miles
neither holds vacuum when applied with a hand vacuum pump.

Getting the following code:

00428B Boost-pressure control, low-pressure stage, control deviation.

Seems to only be triggered after pressing the brakes then going into full acceleration.

Thanks for the feedback - seems like maybe this isn't as big of an issue of X5 vs 335D - I'm at 105k - no codes related to boost, car accelerates fine.

I have had to have my red boost hose connected 3 different times in 30k miles over the past year. Thinking that may have been my issue in the past.

On further study, the new pressure converters do not hold vacuum either. the only way to test them would be while the car is running and that would be very tricky as well.

I found that the vacuum reservoir has a very small leak. The reservoir connects to the pressure converters and affects overall vacuum in the system. so they converters might or might not be faulty.


I will report back once I remove the reservoir to see where it cracked.


Edit:
the pressure converters turned out to be fine. Vacuum reservoir has a leak, not noticeable on visual inspection.

Did a new vacuum reservoir fix the issue?

Yes it did.

Do you have a part number? I’m chasing an odd noise at shutdown and fluctuating brake pedal feel. I’m hoping it’s not the brake booster.

13627808456


This is a useful thread to diagnose your Vacuum system.

Turbo Control, Vacuum System, Pressure Converters etc.

That part number is coming up as a bracket, not a reservoir. Is the bracket that holds the pressure converters actually a reservoir?

yup it's a bracket that is a reservoir that is a bracket.

to test it it's very simple just disconnect the vacuum lines going into it and apply vacuum with a vacuum pump and plug the other tube with your finger. no need to remove the entire piece.

even a minor leak can grow into a bigger leak when the car is vibrating and hot. if you are going to do any work there Id say replace it. and do the vacuum lines as well.

https://i.imgur.com/3pfGHJSl.jpg

what are you applying vacuum with?

Thanks for the update and info :thumbup:

I plan to pick up a hand pump this week.

Upon shutdown I hear a distinct buzzing coming from under the intake manifold near where the VSV is for the motor mounts. Once the motor mounts VSV is de-energized, the buzzing rapidly dies down to nothing. And the brake pedal becomes hard much sooner Han expected. I’m thinking at the very least there’s an issue with the check valve at the booster.

When I block one nipple and apply vacuum to the other, my reservoir makes unpleasant noises and the vacuum leaks down. So I guess that needs to be changed.

I thought of wrapping the new reservoir in aluminum duct tape to help it cope with heat better. It probably cracks due to constant expansion and contraction since it takes a lot of heat from the turbo.

Just thinking of ways to minimize maintenance in the future since the part is not upgraded and will probably fail in another 100k

part is cheap but removing it is a royal pain.