How does the BMW E39 sucking jet pump (aka suction jet pump) work & how does it fail?

Originally Posted by Steve530

Yes there are two sucking jet pumps.

Either that, or one of them is mis-named in the engineering diagrams (I'd suspect the vacuum diagram since it is already known to be wrong in other areas).

Originally Posted by Steve530

One is attached to the brake booster and is used to increase vacuum during periods of low intake vacuum.

Hmmm... a 'vacuum' SJP.

Originally Posted by Steve530

The other is in the fuel tank and is used to transfer fuel from the right side of the fuel tank to the left side of the fuel tank.

Hmmm... a 'fuel' SJP.

I think the name should actually be suction jet pump. It was poorly translated from the German.

The term "jet pump" describes a device that uses a venturi to move fluids, like shallow well pumps.

The BMW design engineers used the same type of device to solve two different problems. I think the term is appropriately applied to both the brake booster SJP and the fuel tank SJP.

Wow, this thread has really taken off. I have been trying to hunt down the cause of my PO171/174 codes. That is where the thread "Different Scanner , New Codes" originated.

The other day I decided that I would go ahead and cut the clamps to the SJP and inspect it. The pump itself appeared to be fine. However, the hose from the intake to the pump had somehow wore itselfdown to the inner linnings. I went to Napa and had a new hose cut to replace the worn one out.

This did not work because of two reasons - 1. The OEM hose is form fitted to allow the brake booster hose and the vacuum line from air boot to line up correctly (On the 540). The new hose was not strong enough to handle the curving requiered. This made the hose pinch.

2. The same hose is flared out so it can connect to the jet pump correctly. I managed to get the hose on but damn near developed a case of carpil tunnel.

I ended up buying the correct hose from EAC which should be here today or tomorrow . Another problem I encountered was the line to the brake booster. It was showing its age. When I tried to reconnect the jet pump back on, the hose just started splitting. So I ordered a new hose for the booster as well. I just hope I dont break the fitting to the booster while trying to remove the old hose.

I will report back today or tomorrow to confirm that my codes have been resolved.

Steve530, over here today, found an excellent picture of the sucking jet pump elusive connection to the intake manifold in the back of the M54 engine:
- For all to benefit, WHERE are the ends of these hoses in our beloved E39s anyway?

Originally Posted by Steve530

I was browsing and found a nice photo of the back of a M54 intake manifold with hoses attached. I edited and annotated the photo to show the location of the attachment of the fuel tank breather (purge) valve and the suction jet pump.

For the crosslinked record, here is the original picture, un-annotated and shrunk to 640x480 pixels.

Here's more information just now from Steve530 on the location of the manifold vacuum to brake booster suction jet pump:

Originally Posted by Steve530

I didn't notice the CCV end cap until I zoomed in on the photo. I've added labels for that cap, the SAP one-way valve, and the SJP for clarity.

Note also that this photo shows the older style tube that connects the CCV to the dipstick tube. The newer style has a 45 degree bend instead of the 90 degree bend in this photo.

just to add to this post

i saw where the top had come off of the vacuum multiplier. I had this happen to me while changing out my ccv.

in looking closely as to how it is put together...they glued the top where the check valves are... to the body...you can see the red ring is a small amount of glue

without removing it from the car i carefully glued it back together in a similar way....be sure not to put too much on there so none gets on the check valves.
just around the edge...then seal the top with a thin layer around the edges.

it is stronger than it was before and sealed better around the top.

I carefully scraped the old glue off until i liked the fit....it fits in there very snug almost like it would have sealed without being glued. keep in mind you should test fit it a couple of times in there before you use the glue....it can only go in 1 way...it cannot be turned clock or counter clockwise in the housing and the glue dries withing 5 minutes. it was a 2 part epoxy plastic adhesive....

when i priced this part is was over $100 and included the vacuum lines. The glue was $8 plastic glue from autozone.....i did smoke test for vacuum leaks....non found

Originally Posted by bluebee

How on earth did you realize that the SJP was broken?

BTW, I've never seen one outside the vehicle - and I only noticed mine about a week ago ... so ... may I ask ...

Did I get the annotations and orientation correct below?

The upper arrow is wrong. Flow is down both legs of the Y. The bottom of the Y does indeed face down in the car and that end goes to the intake manifold on the underside of it.

The venturi description is correct. There's two (orange) check valves on the booster because the non-venturi side gets the booster pressure down fast to one level, then the venturi side takes the booster pressure down lower to another level.

For the record, today I decided to clean my ICV and in order to get to the clamp bolts for the boot over the ICV, I had to disconnect the Torx holding the sucking jet pump venturi valve to the M54 engine.

Here's a picture for your edification:

Originally Posted by bluebee

On the M52, the vacuum port of the CCV goes to the fuel pressure regulator!

** This doesn't hold for pre-98 M52 engines. We have a different CCV part, the face of which plugs directly into the manifold (it gets vacuum from there). It has no connection to the FPR.

Does anyone know where the sucking jet pump is supposed to mount on a pre-98 M52? Mine just kind of hangs there in the engine bay, supported by it's hoses. I don't think that's right

Stuart

I was looking for a picture for another user's question when I ran into this nice photo by Michel showing the 2002 525i SJP in situ.

Originally Posted by mmm635

In the picture below you will see the ICV behind the DISA valve. On the left side you will see the electrical connector and on the right side the pipe that leads into the intake elbow is the other reference.

For the crosslinked record, this useful information was posted today:

Originally Posted by Gootz4u

Hello, I need to buy a sucking jet pump for my 2001 540i. I found it on Amazon. Is this a safe site to purchas this part? Or does anyone know where I can buy this at? Thank You guys.

Originally Posted by ECSTuning

Sounds like you're looking for 11611440135, I have it available HERE. Below is a photo of the pump for reference.

We just launched USPS and FedEx shipping, majority of parts can now be shipped for a lot less than they use to.

For the record, the SJP 'might' be implicated in Poolman's situation today:

Originally Posted by poolman

The cars brakes act funny from time to time--sometimes when I get on them with light pressure the pedal seems like it goes unexpectedly down about a 1/4 inch and the car brakes hard when this happens--but it's only happened a few times over the last 6 months since these lights have been on--that is the reason I'm thinking it's the pressure sensor

Originally Posted by poolman

The pedal isn't hard to the feel--when I stated that the pedal fell 1/4 inch it fell and the cars brake came on to stop the car hard--as if I had layed down on them somewhat--

Originally Posted by poolman

I have replaced two of the wheel sensors and have two that haven't been replaced--still have the ones that I remove, one from the front and one from the back. Thinking about using those on the other side and see if it changes anything. The lights will come on for a moment then go away and do that all day long. Sometimes when the weather is with high humidity the lights will stay on for an hour or so --don't know what to think--it's getting warmer here now--that will give me a chance to look more into the cause's.

Originally Posted by johnstern

Poolman-I would also inspect the suction jet pump. That is the Venturi device that's plugged into the intake tube at the F connector. The thin hose is a vent for the fuel pressure regulator. The thicker hose goes to the suction jet pump that increases vacuum (above manifold vacuum) to the brake booster. If any of the hoses are split, if the device is cracked or damaged or if the vac hose to the IM is not attached, etc., you would have these symptoms.

Originally Posted by glhx

just to add to this post

i saw where the top had come off of the vacuum multiplier. I had this happen to me while changing out my ccv.

in looking closely as to how it is put together...they glued the top where the check valves are... to the body...you can see the red ring is a small amount of glue

without removing it from the car i carefully glued it back together in a similar way....be sure not to put too much on there so none gets on the check valves.
just around the edge...then seal the top with a thin layer around the edges.

it is stronger than it was before and sealed better around the top.

I carefully scraped the old glue off until i liked the fit....it fits in there very snug almost like it would have sealed without being glued. keep in mind you should test fit it a couple of times in there before you use the glue....it can only go in 1 way...it cannot be turned clock or counter clockwise in the housing and the glue dries withing 5 minutes. it was a 2 part epoxy plastic adhesive....

when i priced this part is was over $100 and included the vacuum lines. The glue was $8 plastic glue from autozone.....i did smoke test for vacuum leaks....non found

I found the jet pump on BMWofsouthatlanta for 45.80 shipped. You may wanna check there?