[Gizm0]

Hey guys,

I'm going to replace all the vacuum lines as a preventive maintenance and need to know exactly what all I need.

I'm thinking these two between the vacuum canisters and the actuators:

https://www.ecstuning.com/BMW-E92-33..._3.0L/ES26380/

https://www.ecstuning.com/BMW-E92-33..._3.0L/ES35203/

What else do I need?

Thanks!

[Lshaw]

http://www.verociousmotorsports.com/...ld-by-the-Foot


This is the vacuum hose i used, was recommended by other members on here.

[LQQKOUT]

I would just buy a few FT of 3.5mm or 4mm vacuum line and run that. No need to replace the plastic part unless it's broken. You need to go from the dual vacuum fitting on the big line on the driver side, to the small plastic lines that go over the valve cover. From the plastic lines to the vacuum canisters. Than from the canisters to the boost solenoids. From there you'll find some small lines that go to different T fittings and after that you need to go from the fittings to the wastegates. The last parts is the hardest. I changed mine when I did my turbos.

[LQQKOUT]

Originally Posted by Lshaw

http://www.verociousmotorsports.com/...ld-by-the-Foot


This is the vacuum hose i used, was recommended by other members on here.

Same one I used. I used 3.5, but I think 4mm would have been better. So done more reading and find out what size everyone else uses.

[ferocity02]

Originally Posted by Gizm0

Hey guys,

I'm going to replace all the vacuum lines as a preventive maintenance and need to know exactly what all I need.

I'm thinking these two between the vacuum canisters and the actuators:

https://www.ecstuning.com/BMW-E92-33..._3.0L/ES26380/

https://www.ecstuning.com/BMW-E92-33..._3.0L/ES35203/

What else do I need?

Thanks!

Don't bother buying OEM lines. As mentioned, buy a bunch of tubing and replace each line individually. Remove a line, cut a piece of hose to the same length, install, and repeat.

I bought 17' of the 3.5mm line from Verocious and it worked great. I think I had 4-5' left over, but it's always best to have extra.

[Gizm0]

Thanks fellas! I bought 17ft of that hose you recommended.

[Wolf 335]

So no one is still able to provide information as to why bmw put vacuum hoses with internal diameters of 1.8mm and 2.0mm?

On here general consensus seems that everyone is buying these vacuum lines from verociousmotorsports site that are 3.5mm internal diameter. That's a significant increase when considering bmw's decision to differ the two lines with 0.02mm.

I would like to know why everyone is deviating from the manufacturers requirement and what are the benefits of going with a larger internal diameter?

[lukasB]

larger ID vacuum lines will transfer air faster

[siphor1989]

A little tip on removing the old lines. Make a small slit in the line where it connects to the plastic nipples using a sharp razor blade. This way you'll be able to remove the old lines much easier without risk of breaking the plastic nipple connections.

[Emilime75]

Originally Posted by Wolf 335

So no one is still able to provide information as to why bmw put vacuum hoses with internal diameters of 1.8mm and 2.0mm?

On here general consensus seems that everyone is buying these vacuum lines from verociousmotorsports site that are 3.5mm internal diameter. That's a significant increase when considering bmw's decision to differ the two lines with 0.02mm.

I would like to know why everyone is deviating from the manufacturers requirement and what are the benefits of going with a larger internal diameter?

If you're looking at vacuum lines for your specific model/motor, most vendors state 3.5mm is the right size line. Considering how many have replaced their lines with this size, and had zero issues, I don't think the size is all that critical, as long as it makes a good seal at every connection without leaking.

[Wolf 335]

Originally Posted by Emilime75

If you're looking at vacuum lines for your specific model/motor, most vendors state 3.5mm is the right size line. Considering how many have replaced their lines with this size, and had zero issues, I don't think the size is all that critical, as long as it makes a good seal at every connection without leaking.

EDIT: 3.5mm is the vacuum hose ID 1.8mm and 2.0mm are the sidewall thickness dimensions. Thanks to Emilime75 for clearing this up.

So realoem states that the vacuum hoses outside diameter is 3.5mm

Internal diameter for hoses #5, #6 and #7 is 1.8mm (wall thickness = 1.7mm)
- number 5 & 6 are braided around the oil filter housing.
- number 7 is not braided.

Internal diameter for hoses #8 is 2.0mm (wall thickness = 1.5mm)
- these go to waste gates and are braided.



Could it be that someone mistakenly took the outside diameter dimension and applied it as an internal diameter, and from here the masses followed without questioning? Its quite possible.

I'm just curious as to why bmw engineering team would place a significance on differentiating vacuum hoses by such a small amount of .02mm internal diameter, thus reducing the wall thickness.

Saying that the system is more responsive with bigger (3.5mm) vacuum hose ID doesn't make sense as the pump needs to remove more air before the vacuum is applied downstream (example: waste gates).

Vendors may be saying that 3.5mm is ok, most likely as it is readily available and in stock. Sourcing 1.8mm and 2.0mm is not so common and therefore they don't carry those sizes.

People may be running a wider hose but that doesn't mean that it is running at its peak performance, and vacuum pumps may have to work harder.

Any thoughts?

[lukasB]

Originally Posted by Wolf 335

So realoem states that the vacuum hoses outside diameter is 3.5mm

Internal diameter for hoses #5, #6 and #7 is 1.8mm (wall thickness = 1.7mm)
- number 5 & 6 are braided around the oil filter housing.
- number 7 is not braided.

Internal diameter for hoses #8 is 2.0mm (wall thickness = 1.5mm)
- these go to waste gates and are braided.

Attachment 1782715

Could it be that someone mistakenly took the outside diameter dimension and applied it as an internal diameter, and from here the masses followed without questioning? Its quite possible.

I'm just curious as to why bmw engineering team would place a significance on differentiating vacuum hoses by such a small amount of .02mm internal diameter, thus reducing the wall thickness.

Saying that the system is more responsive with bigger (3.5mm) vacuum hose ID doesn't make sense as the pump needs to remove more air before the vacuum is applied downstream (example: waste gates).

Vendors may be saying that 3.5mm is ok, most likely as it is readily available and in stock. Sourcing 1.8mm and 2.0mm is not so common and therefore they don't carry those sizes.

People may be running a wider hose but that doesn't mean that it is running at its peak performance, and vacuum pumps may have to work harder.

Any thoughts?

These are 3.5mm ID hoses with 1.8 and 2.0 mm walls making them 7.1 and 7.5 mm OD (wall thickness x 2 + ID)

[Wolf 335]

Originally Posted by lukasB

These are 3.5mm ID hoses with 1.8 and 2.0 mm walls making them 7.1 and 7.5 mm OD (wall thickness x 2 + ID)

Thank you sir. What you just said is correct.

I just took a caliper and took a measurement. Your numbers were bang on!

I think my confusion came from fcp's site as someone asked what the internal diameter was and they stated it was 2mm https://www.fcpeuro.com/products/bmw...11657803732#qa

Once again thanks for clearing this up for me!