Comprehensive m52 vacuum diagram guide

vetaldj · Jul 12, 2011

Ok, I posted this in post for m62 engine but it was probably not right, so why wouldn't we create something for M52? Hopefully it will help somebody...

OK, my few cents on this...
Currently I'm changing all vacuum hoses I can find in my 1997 528i. For now I found 2 diagrams with them:
1. Secondary air pump vacuum control
Here, I changed number 7 and 10 already with 3.5mm vacume hose. Wait till weekend to change 13 and 15 as I need to remove more stuff to get to them.

2. Fuel tank breath valve.
Here I changed 3 and 4 for now with 7mmx12mm fuel hose. Original is some kind of elbows, and they looks like fuel pressure lines with fabric inside. I did them with regular fuel hoses. Wait till weekend to change 8, that goes from connector to intake manifold. That's the one I asked in other post.

3. Also I changed one hose that hose from microfilter housing to intake manifold, it's 1/2'' or 13mm hose. It also has fabric inside as pressure hose but I changed with standard vacuum. I didn't find diagram for this one, just read about it here, cn90 wrote about that hose in his CCV replacement thread. See first pic in post where the highest "Cut this clamp" wording located.

Is there any other vacuum lines I need to replace?

Thanks!

gmak2012 · Dec 4, 2013

2nd Diagram hoss 3 and 4

I believe that 3 (second diagram) is a hose that carries gasoline fumes. 4 is a vacuum hose, and so is 8. Anyone using silicone hoses should use an appropriately-lined one for #3 - but probably best to use fuel hose as was indicated in the 2011 post.

I've recently done all of these hoses (not doing 3 unless necessary since it looks like a PITA to the fuel filter which is under the drivers seat in the 1998 528i) except 4 and 8 in the second diagram. Those are up next, as soon as the weather gets around 0 degrees C on a weekend.

lsrguy98 · Jan 10, 2014

Hi. Did you ever locate a vacuum schematic for the 528i? I have a 1999 and the hoses are so brittle they just snap off.

Thanks

gmak2012 · Jan 11, 2014

Hello? two posts above.

Look two posts above.

bluebee · Jan 11, 2014

I commend you for opening a specific thread on the M52, which should, in the end, identify all the vacuum hoses, their diameters, their materials, their lengths, and their starting and ending points. I would also suggest adding all the endcaps, and the solid plastic pipes.

I've done all that, for the M54, so you can use these threads as reference starting points in your combined endeavor for 528i owners.

- How to locate all problematic (between 1/8" & 9/32" ID) 3.5x1.8mm, 3.3x1.8mm & (between 17/64" & 9/32" ID) 7mm ID vacuum tubing (single material), vacuum hoses (multiple material), 3.3mm OD curved vacuum pipes (rigid tubes), 3.5mm & 7mm ID vacuum endcaps (closed end) & 7x3mm manifold o-rings (1) & 7.52X3.52mm and 9.2X2.8mm fuel injection o-rings (1) & gaskets (1) on the M54 engine & where in the USA to get new vacuum tubing & vacuum caps (1) & what SAE sizes to get for all the metric M54 engine vacuum tubes, hoses, pipes, and caps (1) & correcting the F-connector errors in the realoem diagrams (1) & finding the ends of hard-to-locate vacuum tubes (1) & sorely needed clarification on how the M54 CCV vacuum port works on the M52 CCV valve connection to the fuel pressure regulator connection (1) & how to make, borrow, or buy lean-condition misfire test tools to test for vacuum leaks & lean conditions (1) (2)

gmak2012 · Jan 11, 2014

Sort of related to vacuum lines

You might want to think about changing the grommets that are where the ICV and CCV are attached to the intake manifold. A bit of a PITA - but since you're already in there up to your elbows..... They develop wrinkles and nicks that create leaks.

lsrguy98 · Jan 11, 2014

Hi. Your 1997 528i vacuum drawing is different than the 1999 528i that I have. I started a separate thread showing a picture I took of the vacuum lines from the sticker under the hood. I plan to replace all of the lines although my main issue right now is to get my car running. It won't idle and the engine light stays on. In trying to look for vacuum leaks I tugged on one of the lines a bit and it was so brittle it just snapped off. I love my car but it sure can be frustrating sometimes. I asked about an ODM 2 scanner on here also.

Thanks for your input.

gmak2012 · Jan 11, 2014

The 1999 would be for an M52TU engine not M52

The M52TU engine more closely resembles an M54 engine than an M52 one. Try looking on REALOEM.COM where you can enter the last 7 characters of your VIN and access all the diagrams.

Try these links
http://www.realoem.com/bmw/showparts.do?model=DM63&mospid=47585&btnr=11_2203&hg=11&fg=45
http://www.realoem.com/bmw/showparts.do?model=DM63&mospid=47585&btnr=11_2680&hg=11&fg=45

lsrguy98 · Jan 11, 2014

Hi.

Thanks for your help. I'll take a look.

lsrguy98 · Jan 11, 2014

This is the drawing that most closely resembles mine. The only issue is that the hose coming from the valve on the far left comes out the rear of the pump and not the front. Also, I can't see it yet but the other end feels like it goes directly into the head and not to another valve. I guess as I take it apart I'll know more.
http://realoem.com/bmw/showparts.do?model=DM63&mospid=47585&btnr=11_2203&hg=11&fg=45

gmak2012 · Jan 11, 2014

Sometimes RealOEM is wrong.

If you enter the last 7 digits of your VIN, you should get the correct drawing on REALOEM. If you're really a 1999 (through and through) then you likely have the M52TU motor (as I mentioned before). And it will be closer to the M54 than the M52.

What I did when I went into my 'vacuum hose DIY', is I bought a bunch of different sizes in silicone hose (not the lined type) so that as I found hoses, I just cut the length that I needed. One suggestion is to mark everything that you pull out and where it goes to. I used medical tape and a sharpie for this. You'd be amazed at how quickly one forgets (and without a REALOEM diagram, it's perilous turf).

Good luck to you. I'll be going back in, in the spring to take care of #3, 4, and 8 on the original 2011 diagram.

lsrguy98 · Jan 11, 2014

Hi. I went on the site and listed the last 7 of my VIN. It told me it was a 1999 but produced in Sept. of 1998. I was curious about the smaller piece of hose that fits inside of the the two larger sections that fit on the valves. They say it's a hard emissions hose. Do you have any idea what the purpose of that is?

Thanks.

gmak2012 · Jan 11, 2014

Without a picture, it's hard to tell what you mean

I don't know exactly what you're looking at or which parts you mean. Give me a number and show me a picture.

lsrguy98 said:
Hi. I went on the site and listed the last 7 of my VIN. It told me it was a 1999 but produced in Sept. of 1998. I was curious about the smaller piece of hose that fits inside of the the two larger sections that fit on the valves. They say it's a hard emissions hose. Do you have any idea what the purpose of that is?

Thanks.

lsrguy98 · Jan 11, 2014

One more questions.

So when they say "Ended" after the part name does that mean it's no longer being made?

03 VACUUM PIPE 1 09/1998 08/1999 11737546138 ENDED
only in conjunction with
03 VACUUM PIPE 1 09/1998 08/1999 11727574490 $27.94
only in conjunction with
-- Bracket 1 09/1998 08/1999 11787503123 $3.37
-- Valve 1 09/1998 08/1999 11727540472 $114.19 +core
03 VACUUM PIPE 1 08/1999 06/2005 11737500269 ENDED
03 VACUUM PIPE 1 11737546138 ENDED
03 VACUUM PIPE 1 11727574490 $27.94
04 VACUUM HOSE BLACK 1 09/1998 11657803732 $16.43
04 VACUUM HOSE BLACK 3,3X1,75 1 09/1998 51731257971 ENDED
04 VACUUM HOSE BLACK 3,5X1,8 1 09/1998 11727545323 $14.82

gmak2012 · Jan 11, 2014

ENDED means superceded

You can still find them being made aftermarket - but the part was replaced by a newer version which is usually right below it in the table.

lsrguy98 · Jan 12, 2014

Parts 3 and 4 are the parts I'm trying to replace. They were so brittle they snapped. Part 4 is a larger hose and part 3 is a smaller solid plastic hose of some sort. Part 3 fits into part 4. Here's a pic.
http://realoem.com/bmw/showparts.do?...03&hg=11&fg=45

03 VACUUM PIPE 1 09/1998 08/1999 11737546138 ENDED
only in conjunction with
03 VACUUM PIPE 1 09/1998 08/1999 11727574490 $27.94
only in conjunction with
-- Bracket 1 09/1998 08/1999 11787503123 $3.37
-- Valve 1 09/1998 08/1999 11727540472 $114.19 +core
03 VACUUM PIPE 1 08/1999 06/2005 11737500269 ENDED
03 VACUUM PIPE 1 11737546138 ENDED
03 VACUUM PIPE 1 11727574490 $27.94
04 VACUUM HOSE BLACK 1 09/1998 11657803732 $16.43
04 VACUUM HOSE BLACK 3,3X1,75 1 09/1998 51731257971 ENDED
04 VACUUM HOSE BLACK 3,5X1,8 1 09/1998 11727545323 $14.82

Thanks.

lsrguy98 · Jan 13, 2014

I found this line that pretty much answers all of my questions.

Thanks for your help.

http://www.bimmerfest.com/forums/showthread.php?p=6379203#post6379203

lsrguy98 · Jan 13, 2014

I replaced the vacuum hose (3&4) but the same issue occurs. The check engine light is on and it won't hold idle.
I'll head back to the blogs and search the symptoms while I'm waiting for my OBD 2 scanner to show up.

gmak2012 · Jan 13, 2014

I had issues when I changed my vacuum lines

Referring to Post #9, the first diagram. When I changed my vacuum hoses at first the car wouldn't start - and then it wouldn't idle. I believe my first issue (trying to remember) was that I had reversed hoses #10 and 13 where they hooked up to device #11. I was then able to get the car to start by giving it gas, and it rev'd strong - but wouldn't hold the idle and stalled.

The second issue was that the ICV valve had twisted when I re-installed the intake manifold and it was out of the grommet a bit - plus it had pulled hose #15 out of the intake manifold, and the wiring out of the ICV

On your diagram, it would be how hose #7 and hose #4 hook up to device #5 (it thing that do-hickey is #5). Also, where hose #9 hooks up to the manifold

But if the car won't idle, I would argue that one of the places to look is the Idle Control Valve.

I hope it goes well.

Comprehensive m52 vacuum diagram guide

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