Intake manifold is off, working on vacuum hoses
 

Intake is off, doesn't look too bad for 150k miles. Luckily there seems to be relatively little CBU. The swirl flaps are pretty clean. The CBU seems too be concentrated only where the IM and the valve cover meet. Going to think a bit about what the best approach is here.

The soup of hoses, wires and other assorted gadgets that I have uncovered on the drivers side of the engine is incredible. I can't believe the mess and of course everything is covered in black goo. Non of my vac hoses seem bad to the point of leaking but I plan to replace the lot of them. Just wondering what else needs changing while I am in there?

This is what is being performed on my E53 right now. She is currently at the Doc’s office.

Ugh, did a manual cleanup of the manifold as far as possible. Yuk, worst cleanup ever. Everything gets filthy, your hands get filthy and it leaves a ton of trash that is not so clean either. The swirl flaps are solid but have about 1/16 to 3/32 play on the shaft. Clearly some boost is lost from there and the lines under the IM are covered in black goo. I am on the fence whether to replace them with a delete kit. I can't think of anyway to improve the seal on the shafts. Thoughts anyone?

I am spending some time thinking about rerouting the main vac line to the brake booster. There is no obvious reason for it to be under the IM. I'd need to extend the hose from the vac pump and run the hard line somewhere near the main coolant hose. Still have to disassemble it and try out some routing.

Finally the main fuel feed line feels rock hard and I am wondering if I should pee-emptively replace it.....a bit of a bloodletting at $260 from Tischer.

Getting deeper in to this...
 

Waded in deeper and removed all the small vac hoses from the distribution piece in main vac line going to the brake booster. Although very dirty, nothing looks like it is broken or leaking under the manifold. Since the fault code relates to the EGR system I am thinking that the pressure converter under the IM maybe be marginal (there are some posts on bimmerfest and e90post that point this way). The OE item is $140 but I really don't feel like buying a chinese copy and later having to go in a second time.....

On removing the heatshield that covers the vac hoses on top of the turbo I found some very bad looking red and blue hoses. Eventually I will take off the bracket that holds the pressure sensors and the pressure converters. First I just want to reinstall vac lines that control the EGR. If I pull them all at the same time it might become confusing.

I disconnected the hose of the EGR valve that resides under the turbos. After removing the aluminium stiffener plate I could get needle nose pliers up under the turbo and disconnect the red hose.

If only I could persuade myself to go for another session cleaning the Intake with Purple Power. I ordered some long handle brushes to get in there.

Pictures later!

I have an old cattle trough that is reserved for that.... started w an only Ford diesel project, then an infiniti Q45...and multiple barbecues along the way. Sticking a pressure wash wand up into things can help too, provided you know about any small passages that will need pipe-cleaner attention later.

But yeah, is is a messy job. Rubber gloves, even elbow length, just seem way inadequate.....

After scouring the house and the garage, finally decided to use a steel cement mixing tray for cleaning the IM. Since the brick work has been completed long ago the tray is unlikely to get much use again.

I took the main vac hose out. Apart from the rubber bits connecting to the the vacuum pump and the brake booster, nothing much wrong with it. Plan to replace the bits of rubber hose and reuse it.

The engine bay under the IM looks grim. See a picture here of the pressure converter I plan to change.

Borescope and pressure converter
 

So, still procrastinating on the IM cleaning.....but started on installing the new vac lines and taking off the bracket that holds the turbo control items. On the latter, four bolts can be removed easily, the fifth one is a bear. I took off the covers above the ECU and moved the chassis brace out of the way but still haven't been able to get a socket on it properly. More wrestling today....

On the inbound package front it was fairly busy; the long handle brushes for the IM cleaning arrived. The hose for the turbo control arrived and is on the car. (Had to take one small cover off the passenger frame rail to get my hand in there. Same allowed me to pop on the hose for the lower EGR valve.

The pressure converter arrived, the Pierburg branded item saved me nearly half. Also bought a borescope on Amazon, the Depstech is acceptable quality and I could check that my intake valves are indeed clean (enough....). (Not sure if it makes a difference but I always used BMW's LL-04 oil).

Today I will climb in again to get the turbo vac controls off. However, the BlueBus arrived for the E53 and my son will be keen to have it installed. The rain is making it a bit less hot and it should be a good day for wrenching.

I know it is not going very fast but there are a lot of other projects that also want my time.....

The vacuum control block is off
 

But this piece is an abomination that should never have been allowed to be bolted to the engine. With three more hours of engineering and design time this could have been a straightforward item......

I understand that strapping all the engine controls and sensors to the engine block might simplify the installation of the engine in the chassis on the assembly line but this is frankly ridiculous. Even after undoing all the electrical connectors there is one more actuator that is still attached to yet another bracket on the engine block and the hoses are not visible from the front. Also, the wiring for the pressure converters is not in the same harness as the sensor wires. These run behind the engine somewhere and are also unbelievably short. Unfortunately the vacuum hoses are also all unnecessarily short making the disassembly unbelievably difficult for no reason.
:soapbox:

Looking at it now I believe it may be easier to undo the plastic vac reservoir/bracket from the steel bracket on the valve cover. But that is quite difficult to see when starting out on this quest.

Anyhow, I labeled the hoses and now begins the reverse journey. Of course also need to decide whether to replace the pressure converters at this time......

EDIT: Removed the bits of hose that were stuck on the various elements, they were plenty brittle. The videos that show replacing only the bits that are on top of the vacuum reservoir are plain wrong. The heat cycles next to the cylinder head are intense and those bits of hose broke off easily. Decided to order the pressure converters from FCPEuro and a new vacuum reservoir from Tischer, the latter is cheap insurance. Also ordered more vacuum hose from TuneMyEuro as my initial order is already running out.

Some posts on the e90 websites reported better turbo performance after replacing the converters and here's for hoping!!

Good job!


I agree that the vacuum lines are an amazing rats nest, complete with hidden and brittle connection points. I helped one of my sons do his vacuum lines this summer.

Since you have an order from Tune My Euro, I assume you have seen his videos? He has an excellent one on giving a step by step approach to changing the vacuum lines. The link is here.

https://youtu.be/kuXEa1efpxQ



https://www.youtube.com/watch?v=kuXEa1efpxQLove it when he goes into detail on how to get old brittle lines off without snapping the plastic nipples. And he's got a great tip for using a pick to get under some of the electrical connections points and releasing them. Some of these tips are reinforced on the Das Projekt vids as well. Pure genius.

As noted above, the other great resource I found on the topic is the Youtube site of Das Projekt 5seven. He has a 2 part series on the vacuum system. The links are here

https://youtu.be/Qer7vfbx77c

and here.

https://youtu.be/5-1LwCZrGQ8


https://www.youtube.com/watch?v=5-1LwCZrGQ8
Really great information on both of the sites. Watching the above videos made the work so much easier. Without them I'm sure we would have (at best) taken much longer, or (at worst) "fixed it till we broke it" (as Doug Huffman might say). The only thing I did that wasn't covered on the vids is use blue painters tape to number all the lines, and used a black Sharpie to number the connection points on the vacuum box. And of course I took a bunch of pictures beforehand. Not wanting to ever have to deal with brittle lines again, silicone replacement hoses were used.

TriX5 - I realize you probably watched the above vids, but the information might be helpful to others who are contemplating this work. Again, kudos to you!

This is a great source of info. I had not seen the videos, so far only ordered a few minor parts from Rodriquez. This is so much clearer than the ones I found. He is very clear and works quickly and in an organized way. Thank you for putting these links! This type of info is what creates value for the board!

The 335d has much better access despite being a smaller vehicle, I don't know how BMW manages to make the X5 so horrible to work on despite being much larger. It always seems to me that they first design the sedans and then, to design the SUVs, they try to only raid the parts bin rather than designing them from scratch. The placement of the vacuum kit is awful, the frame for it is oversized and the design excessively convoluted. Apparently BMW's engineers are ashamed of nothing and I am just ranting at the wall :-)

EDIT: Just ordered a couple of the electric vacuum valves as well (the Pierburg branded ones), just to be sure that the entire vac system is at peak performance and to avoid having to go back in there.

I am doing the ordering a bit piecemeal but as I start to understand the system better, as to which item does what), I am making decisions on what to do. And the car will be on jack stands for another week or two anyhow....

Most parts arrived
 

Yesterday received one vibration insulator, one was missing on my IM. I checked in the ports with the bore scope and luckily it is not in there. The IM was off once before when the dealer replaced the GPM and glow plugs, it probably was lost then. (Leave it to the pros....) Can't remember if that was a recall or courtesy. Anyway, the one insulator was $15, not cheap but better than unavailable.

The vac regulators for the turbo change-over and waste gate actuators appeared this morning and I picked up the vac reservoir/sensor bracket from Tischer. The vacuum valves also came and now just missing some more vac hose. The next two days I am busy with non-vehicular stuff so this is on hold till the weekend.

Next Chapter in the Saga
 

Today it was time to rig up the vacuum block with the new Vacuum Reservoir / Connections Bracket and the new Pressure Converters as well as the new EL-Valve for the turbo bypass. After the painful process of extracting the reservoir and the steel bracket as one unit, I concluded it would be way easier not to put it back that way. I put back the steel bracket with the converters first and the reservoir only after all the hoses were installed. As mentioned before, to get the hoses off the waste gate and the LP-EGR valve from below the car, you need to remove the stiffener plate and the plastic cover from the passenger side frame rail, then reach in from below. I had installed these already a few days ago.

I mounted the new converters on the steel bracket and the new EL-valve on the secondary steel bracket which I had left on the engine. The EL-valve slots in front to back, difficult to explain but easy to see when you are in there. Once the steel bracket with the converters was back in its place, I cut and installed all the new vac hoses on the actuators, valves and converters except for the red hose which was cut to size but need not be connected to the EL-valve yet. Once I had rigged it all up, then slipped the reservoir over the three studs on the bracket and connect it with the three M10 nuts. I used a magnetic socket to avoid them going AWOL.

Then it was time to figure out the connections, they are not interchangeable except for the temp sensors on the Cat/DPF. The pre-cat temp sensor (next to the O2 sensor on the Cat/DPF housing) goes to the yellow/blue-yellow/brown and the pre-DPF temp sensor (furthest back on the DPF) goes to the gray/white-brown lead. For reference the temp sensor on the LP-EGR valve goes to the red/yellow-brown/white lead. Last thing was to connect the red hose to the EL-valve.



****I think that to get to the pressure converters it is probably not necessary to remove steel bracket from the valve cover nor disconnect the electrical connections other than the turbo bypass EL-valve (since it is mounted on the secondary steel bracket and it also happens to be the easiest to disconnect). I would disconnect the two hoses on the diff pressure sensor and the hose of the exhaust pressure sensor to make it easier to move the reservoir out of the way. Once the three hoses and the EL-valve are disconnected, cut the red hose at the EL-valve and the hose running to the large actuator (turbo change over) under the vac block. (The remainder of the latter can easily be removed using a small box cutter or a scalpel) Now the shield needs to be removed from the reservoir, lift it from the back (hard cause the harnesses from the ECU will fight you) and then pull it clear to the passenger side. Once you have the shield out, undo the three M10 nuts holding the reservoir to the steel bracket. The reservoir should now have enough movement to get at the converters to replace the hoses or replace both. ***

I did the vaccum reservoir and the pressure converters and lines last year. It was not a fun job at all. This started with one of the 3 converters failing and throwing a code leaving me in limp mode in the middle of a snow storm heading to the airport to pick up my sister.

The vacuum block is back on the car and most of the hoses are on. Today my mightyvac tester arrived. So, hopefully tomorrow I can check the three actuators on the turbo. I'm intrigued by the vacuum actuated motor mounts, I doubt they will hold vacuum but we'll see.

The intake manifold is taking a lengthy bath in purple power as of 5pm today and judging by the consistency of the liquid after running it through twice, I will need at least two more jugs of PP to clean it (which I went to get after dinner). The stuff that came out is super black and viscous.

I think I will reinstall the swirl flaps for now, just not convinced that the motor will be the same if I delete them. I am wondering if I could get some o-rings flexible and thin enough to slip them on the shaft from the outside to provide some additional seal though I know it would not be anywhere near perfect.

Purple Power! Cleaning the intake manifold.
 

So, I got three gallons of Purple Power and frankly didn't expect too much from it. I made a plug for the throttle body opening from a plastic bag and some rags. Put a bolt into the MAP grommet and with the ports pointing up it holds precisely a gallon of liquid. Looking into the intake opening there seemed to be a fat cake of carbon gunk stuck to the innards of the IM.

The first gallon of purple power I let sit overnight and it looked like spent motor oil when it came out, unbelievably black and viscous. Looked promising in terms of cleaning power but clearly needed more. So, I drained the first lot and put the second gallon in, which sat soaking for two nights. Drained it this morning and peering in to the intake opening looked quite promising! No more caked on gunk in my field of view. Not bad! On to phase 2.

I had borrowed a Karcher pressure washer from a friend to clean the pavers on my patio (had to fix the pressure switch first but that is a different story! :--) and decided it might just work on the intake manifold to blast out any remaining gunk. I put a work glove over the air intake using quick ties and cut off one finger of the glove to stick the wand in to the IM to avoid it all blowing back on me. Laying it with the ports down in my oil drain tray worked like a charm. A couple of gallons still came out black but after a few more tries it was mostly clear. However, a lot of solid gunk still came out that I could scoop out of the bottom of the drain tray. I went at it with the pressure washer until no more gunk appeared.

I plugged the holes anew and left it soaking with the last gallon of purple power. Tomorrow I will give it another shot with the pressure washer and hope to be done with it. Before bolting it back on the head I will run a borescope through to assure there are no chunks of carbon anywhere in there. I don't want the engine to swallow any large pieces even if they are soft.

In a nutshell, quite impressed by the ability of the Purple Power to dissolve this stuff! In terms of difficulty no more than a 2 of 10 but on the scale of gross and horrible a solid 10!!! :-) More later, will try and shoot a picture of the borescope images if I can.

^Good to know. Thanks.

Just buckets full fun! EGR cooler valve stuck....
 

This morning checked on the chemical experiment with the intake manifold and still looks very black, I may have to go for Purple Power gallon #4. First will let it sit overnight one more time. Then pressure washer tomorrow and the next PP treatment after that. Doubt I will go for #5.....I want it back on car to see if all of this leads to any improvement!

So now that I have another day or two, decided to put my new Mightyvac vacuum tester to work. Most everything seems to works as advertised but the motor mounts get up to 15 vacuum then fail. Pretty sure those need replacing.

Finally went to check the EGR cooler (which couldn't have failed as I replaced it only 10k/18 months back....before I shipped it to Europe). Aaaaarghhhh, it held vacuum but no movement of any kind.... :-( Tried to move it by hand, no luck. Try to move it with pliers, nothing! Finally decided to remove the EGR cooler altogether and with channel lock pliers I could move the valve but only with a lot of effort! Half a can of WD-40 later (and a lot of elbow grease) it moves but not as freely as I'd like. Left it to soak with a good dousing of WD-40 on the inside. [EDIT: It is a Behr/Hella unit]

I am starting to wonder what hasn't failed in the emissions control system? Daaaang! Don't have time to work on it every day and this starting to be a long haul....

Added some pics. The IM turned with ports pointing up so that a few corners will be soaked that were not previously treated laying it down. The EGR cooler in resting position (valve is open) and activated with the mightyvac. Finally, the EGR cooler bolts on the left are much easier to undo if the lower intake duct is out. It is held in by a bolt (ext torx) and the connectors at the top.

Nice job! And thank you for sharing.

It runs and quite smooth too.
 

Dieselfan, UR welcome :-) Trying to add some details about the process that I found hard to find despite many threads on this topic.

Last week I was reading Sunny-J's thread on his maintenance adventures and I decided to order the seals for the vacuum pump as he had done from DUDMD. Arrived quickly and in order from across the country! Good service. Over the weekend I cleaned the swirl flaps with some purple power, that stuff is amazing and very strong (it dissolved the orange paint in my oil catch tray.....)

So, the parts all having arrived, I decided to start the engine up today. The vac pump comes off easily and the seals are easily replaced. Then put the EGR cooler back on and the lower intake duct. Finished tying down all the hoses and wires. Assembled the intake manifold swirl flaps and motor, EGR valve. (decided to put the throttle body after the IM was installed. Popped the IM on the engine......and realized I forgot to put the 12 seals on the intake ports.... I had only begun to tighten 2 bolts but definitely felt a bit silly. One little trick is to get the IM lined up is to keep the front of the IM lifted and spot it going on to the rear stud, then lower the front of the IM. It fell in to place easily....twice.

After wrestling with the covers I removed from above the ECU and searching for the front reinforcement bar which had fallen behind a box.... :doh:. Then the ever fun bit of re-installing the fan and the charge hose.

The motor started easily and ran quite smoothly. Not sure which of all the items I cleaned and/or replaced makes the difference but I'm sure that after 150k miles none of it was excessive. Deleted the codes with INPA and none reappeared but I have not driven it as the bottom covers are still off (plan to service the trans and do an oil change. More of this in a few days.

OMG, Ridiculous! Where did those ponies come from and.....
 

....where have they been all this time? Decided to take it iff the jack stands and give it a whirl. The improvement in performance is insane! I even have brakes again! So, I guess my vacuum system was seriously messed up. Cleaning up the intake and swirl flaps probably also made a significant difference.

I saw some posts of people with E90s who had a lot of improvement from changing the pressure converters. And this tallies with that experience. I am so pleased that I decided to tackle this at last.

Next stop, transmission and TCase service.

I changed the pressure converters and electronic valves when I did the VCG back in December and I noticed an improvement in throttle response.

Mine feels transformed, but I am at higher mileage and I had been advised several times to replace the vacuum lines. But....the estimates were typically not far shy of 1k which is too much.
I feel that a trained mechanic could do this in three hours if only the hoses are replaced. Even including taking the manifold off. Replacing the converters and valves would take another hour at most.
Cleaning up the IM Is quite a bit more time consuming, possibly another three hours but it does need to be soaked for 48 or 72 hours at least.
This job is like most other jobs on the X5, once you have done it once it is a lot easier to repeat if need be.

It's not over till.....
 

....all the error codes are gone and so....two codes refused to go away even after the big vac replacement job.

One is the pre-turbo exhaust manifold pressure, the other one a denox sensor. The former has been a constant but getting worse. There are two other codes but I think they result from these two.

Today decided to tackle the former and check that the back pressure pipe is not clogged. Removed the back pressure pipe and fiddled a bit poking a wire thru it. Then thought some compressed air would be good......stuck the air nozzle into the bit of rubber hose and, guess what? Air coming out everywhere from the rubber hose. Leaks like a sieve.

Though a bit of hose would suffice, decided to just replace the whole part as I need new seal rings for the banjo bolt and a few small parts to put the front pan on the bottom back. (Why do "the pros" always lose one or two of the quick release screws and then not bother replace them, aaaarghhh)

I have the sneaking feeling the denox sensor is bad but I prefer to replace one item at a time so as not to confuse myself.

Back to waiting for parts. (Maybe I should try wrestle the gear shifter out of the car as it has a bad switch and its replacement arrived last night. :-)

UUUGHHHH!
 

Replaced the tube for the pre-turbo manifold pressure sensor and replaced the EGR cooler (for the third time!). That took care of two codes.

EDIT 1: Found one post on another forum about a case that said, the EGR bypass flap sticking was caused by a coolant leak inside the EGR cooler, which screws up the shaft on which the flap is mounted. I did note a slight coolant loss over the past year but it was very minor. Definitely seems like my case.

Now, once the engine warms and has been restarted a few times, I still get the downstream Denox sensor code, sensor out of range (post cat). It says the oxygen reading is too low on the over-run? It is not a constant error and the sensor doesn't seem to be totally gone. I am wondering if it is the sensor or something else, SCR maybe? Guess I will start by removing the downstream sensor and cleaning it.

EDIT 2: There seems to be an adaptation set for the functioning of the SCR that is reset by the tech when ever the shop fills the tank. So, I might try and fill the SCR tank and see about resetting the adaptation and if that offers no solution then remove and clean the sensor before replacing the NOX sensor (they are both original to the car....).

If that fails I will have to decide if I can get a used one, replace the probe part (solder it onto the existing electronics) which is about $70-80 or spring for a new one ($300). Anyone gone the route of replacing the probe?

Small victories....and another sensor to replace.
 

Managed to crack the rear NOx sensor free! In the next few days will make time to remove it and clean it up with injector cleaner. Also, managed to install ISTA/D on my laptop and now I can run the test program for the NOx sensors.

EDIT: Yesterday took out the rear NOx sensor and cleaned it then put it back on the car today. Then did the brake bleed using ISTA and my home made pressure bleeder. After completing that task, back to testing the NOx sensors.

After playing with software and driving the car for a bit I realized that the rear NOx sensor is completely dead. So, time to get a replacement.

To close out this thread. Replaced the downstream NOx sensor with a used one, car still refused to reset properly. I had bought yet another NOx sensor since I wasn't sure about the first one being ok. Not sure why my gut told me to get a second replacement but it turned out to be the solution. Now I have an NOx sensor with 35k on the car and all is well. (The seller of the first/faulty NOx sensor refunded my money, happy with that.)

Note: ISTA is not very straightforward to use for this but once I understood it, it helped a lot. On replacing the NOx sensor, the SCR system needs to be reset/sensors initialized, which is a completely separate routine in ISTA. Once you reset the SCR, the pre-SCR temp needs to be brought up to >150C and only driving the car will get the temp up there. Up to that point the SCR system doesn't release readings on the NOx sensor. Have been using the car for a week now and no more faults. This has been one of the most convoluted fixes ever where fixing one problem simply led to finding the next one.

Since it came back from Europe early June, I replaced:
MAP sensor
CCV hose (AARod)
Vacuum lines (every inch of it)
2 Vacuum valves/3 pressure converters
Vacuum reservoir
vacuum pump seals (DUDMD)
IM seals
Hose parts of the main vac lines to the brake booster
Steel line/hose to exhaust manifold pressure sensor
EGR cooler
Nox sensor (rear)

Also, cleaned the intake manifold, performed trans and TC fluid change/reset.

The MAF sensor, EGR valves, differential pressure sensor and exhaust manifold pressure sensor were all replace 10k earlier. The DPF was removed and cleaned at the same time.

In a nutshell, since ~125k there have been a plethora of issues gradually getting worse. If I was in the same position again, I would pull the engine/transmission/sub-frame in one go and do all of this (and add the mech sleeve, engine/trans mounts and valve cover/oil pan gaskets) in one go. Yes, that is major surgery but from the accounts on here all these items will come up anyhow and working on the engine and trans once it out is so much easier and saves many hours that otherwise are spent wrestling with stuff that is incredibly hard to access.