[boostaholic786]

Originally Posted by BobS

Great info OP! Thanks for sharing.

Do you guys have a boost guage? I wouldn't replace the lines unless you had a issue holding boost. Why take the chance of screwing it up?

The lines DO get brittle and become a problem in that particular space because the oil filter housing gets so damn hot and its practically right next to it. And I personally have a p3 vent gauge but 99% of the tunes on the market have a built in boost gauge by using the fuel gauge or oil gauge.....Honestly a five year old could probably replace these vacuum lines haha.

I had the same exact issue and I knew it had something to do with the wastegates staying open like a N/A motor. I just happened to look at the vacuum lines going into the canister and pulled it off and no vacuum. I replaced the top lines first but still no vacuum. I decided to look under the canister and the nipple that the actual line sucks onto was broken. Its held in by one bolt so I went and grabbed a new canister for like 25 bucks from BMW and decided to replace all the vacuum lines. When I traced the line to the brake booster it was brittle and horrible looking which would affect boost. What I did is left a little extra line so its not so close to the oil filter housing or anything really hot. So it could be affecting boost even in the most slightest way and you dont even know it... Just a little preventative maintainance if you want your car running in tip top shape.

[mattsfeir]

Good to see this info is still helping people .

[joro2077]

http://www.verociousmotorsports.com/...Cured-Silicone
Rated at -65 to 400 degrees. 12 foot needed. stollen from turkeybaster's post

[trevor335i]

Thank you so much! My newly purchased 335i has been in limp mode the whole time I've been driving it (over a month) because of a cracked boost line. There was enough slack to cut the cracked portion off (near the nipple) and reconnect. As soon as I did that, no more half-engine light, no more limp mode, and it drives like a completely different car, FAST.

A few side-notes:

1) My bluetooth ODBII scanner, connected to Torque (Android, Samsung GSIII) showed no fault codes after half-engine light, and all sensors/tests checked out fine. To access the fault code, I had to use the onboard computer (click up/down on the shaft arrow button until "check controls" was highlighted, select with the push button, then hold the push button down for 5 sec to display: CC-ID 29). Even though the Torque/ODB-BT adapter didn't detect that code, it performs wonderfully in general, and the adapter only cost me $25 (p!rated the app but will probably pay now because it works so well). The boost sensor now reads 4-5 psi under moderate engine load.

2) The stock lines are not suitable to withstand the temperatures generated in that area. My lines looked totally decrepit, cracked near the nipple coming off the engine, and will have to be replaced (with heat-treated silicone lines) once I have the time/they crack again. They are totally brittle. I had to spit on the nipple to get it back in (huh-huh...LOL!!!).

3) BMW sucks for not making the rear two engine cover hex bolts accessible without taking off two air intake/engine cover cowls/manifolds (about ten 5/19 in bolts, took an hour to take off/reattach). Those two allen bolts are never going back on my engine cover as long as I own the vehicle.

4) Now I only have to get Carmax to replace the rear passenger window regulator. The damn thing (green piece that the cables attache to) snapped (i thought the glass had cracked lol!) I already removed the door panel, peeled back the foam lining and stuck a c-clamp / vice on the runner to hold the window up as it is freezing right now and, at high speeds, having one rear window open generates resonance that makes it sound like you're driving through a wormhole.

Thanks again for your post.

Trevor

[quasitime]

Looks like I'm running into this issue. I had a half engine light come on while accelerating on the freeway the other day.

30FF code

I tested the vacuum as described after turning the car off, and no vacuum.

50k miles, just out of warranty since it's an '07.

Is this a pretty easy replacement? If not, I really need look around for a mechanic in the LA area. I also have warm start issues (A0B4)... and I also want to get an upgraded FMIC.

[CPV]

I had a 30FF underboost code as well on my 07 N54. 1 of the vacuum lines behind the oil filter was the culpit. I changed them all over myself. Cost $10 and 1 hour. Easy job...

[quasitime]

I think this thread should be sticky as well.

Changed mine out and the car drives like a new beast. I can't believe how long I've been driving with lower power and response.

The switch out was easy. Just make sure you have an exacto knife to cut off the old lines from the connectors. Also be gentle enough so that you don't cut into the connects themselves.

[longhorn335]

I had not been boosting for a couple months now, always assumed it was my stock intercooler was responsible for it.. even changed to ETS IC, which I wanted to do anyway, to no avail.. thanks to this thread I checked vacuum lines, and somehow the vacuum hose that connects to the canister bottom nozzle was completely disconnected, just hanging in there.. so I connected it and car's boosting like a champ!

[Brian@MWP]

Great info!

[adrean8j]

Does anyone have an estimate as to how much (length) hosing is needed to replace all of it?

[bas2000]

joro2077 said 12 ft

[adrean8j]

^^^I already found where my leak was (after 2 months of worrying that I might need new turbos, etc, etc...). It was on the vacuum line right next to the oil filter...I went to flex the line and it felt like a piece of plastic instead of rubber. I could actually hear it crackling as I flexed it. So I replaced the lines on the DV's and the two roughly 1.5ft piece running by the oil filter and voila! No more underboost codes, or low speed stuttering.

[bas2000]

cool, what kind of hose did you buy to replace it with?

i'm thinking about ordering the Verocious Silicone Vacuum Hose that joro2077 posted the url for.

[adrean8j]

I just went to Advanced and got some 5/32in by 6ft "ThermoID Windshield Washer Vacuum Tubing". That will do until I can order the good stuff from that link as well (not to mention I can put some color under the hood! )

[Lifted07Duramax]

subbed

[TT3 iN NyC]

in this link...

http://www.verociousmotorsports.com/...Cured-Silicone

what size do we get? we have the following options...

3.5MM
4MM
6MM
8MM
10MM

[adrean8j]

5/32 equals 4mm (its actually something like 3.986mm).
http://www.hamuniverse.com/antfrac.html (conversion table)

[TT3 iN NyC]

Originally Posted by adrean8j

5/32 equals 4mm (its actually something like 3.986mm).
http://www.hamuniverse.com/antfrac.html (conversion table)

thanks!

just ordered 12 feet of black 4mm lines.

[parksjm7]

Finally did it a few hours ago. Thanks OP

[Dynomyte]

I broke the vacuum connector does anyone have the part number I have looked at all diagrams and haven't been able to identify it!?

[Dynomyte]

Anyone?

[maxwell600]

Originally Posted by Dynomyte

Anyone?

http://www.realoem.com/bmw/showparts...75&hg=11&fg=45