2005 ZHP Fuel Leak in Engine Bay... need assistance

ZHOMafia Members:


I have a 2005 ZHP auto, convertible with a very recent fuel leak discovered two days ago.

Leak Description
Slightly in front of the front wheel, inward about a foot, a constant drip occurs once the vehicle is started and running. When I primed the fuel pump several times, I could not see any fuel drip.

Current State
I have removed airbox, cabin air filter, and the engine covers. I did not see any leaking fuel at the fuel rail. Note: Eight months ago, I replaced the fuel filter/ regulator ... no leaks in this area. Will remove splash cover to get a better view of the drip.


Questions
I am assuming that the fuel line between the fuel filter/regulator and the fuel rail needs to be replaced in whole or part.

(1)(a)How does one remove the fuel line in whole or part? (b) Does the splash guard need to be removed to expose the fuel lines?

(2) (a) Does the fuel rail have to be removed? (there are two portions of the fuel line according to realoem.com ... the rear fuel feed [from the fuel filter/regulator ... horizontal] and a second section ..fuel pipes set ...[vertical to the fuel rail)

(3) (a) What type of connections are there between the horizontal and vertical fuel lines? (b) Are they quick connectors? (c) How are the connectors removed/released? ... does it require a special tool? (d) if the vertical fuel line is leaking, does that mean that the fuel rail has to be removed? (e) If the fuel rail has to be removed, is this video correct for removal ube.com/watch?v=Oe87i2yw49U How to Replace Fuel Rail With Injectors 97-06 BMW 325 Xi" by A1-Auto?

In advance, thank you for your assistance.

This is pretty unusual....In front of front wheel? - you mean between wheel and radiator? There isn't al lot of fuel in that area except fuel rail, and injectors for cyl's 1 -3.

The fuel hose is much further back against the rear firewall. The single fuel hose is a quick connect...There is a cheap tool from harbor freight I think, but because access is so poor, I just use my hands and pull back on quick-connect clips while pushing hose forward onto the fuel rail inlet...eventually the whole thing releases and it comes off.

But I would first look for leaks at the front of the rail and injectors for cyl's 1-3...

Check your injectors, I’ve seen them crack and leak externally on M54’s in the past.

Quote:

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Originally Posted by Pilot05

This is pretty unusual....In front of front wheel? - you mean between wheel and radiator? There isn't al lot of fuel in that area except fuel rail, and injectors for cyl's 1 -3.

The fuel hose is much further back against the rear firewall. The single fuel hose is a quick connect...There is a cheap tool from harbor freight I think, but because access is so poor, I just use my hands and pull back on quick-connect clips while pushing hose forward onto the fuel rail inlet...eventually the whole thing releases and it comes off.

But I would first look for leaks at the front of the rail and injectors for cyl's 1-3...

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Pilot05 ... my location description was incorrect ... its near the firewall about a foot or so inward. I inspected the fuel rail ... no fuel leaks.

Remaining Questions

(1) What and where does the "Fuel Return Line" [#16126752189] connect to? Realoem's diagrams do not show the connection point.

(2) (a) In the event that I remove the fuel rail as opposed to the blind approach... do you have any suggestions for the fuel rail removal? On the A1- Auto video they sprayed a non-silicon substance to help release the injectors. (b0 Will WD-40 be appropriate to use to help facilitate the fuel rail removal?

Quote:

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Originally Posted by Satcho

Pilot05 ... my location description was incorrect ... its near the firewall about a foot or so inward. I inspected the fuel rail ... no fuel leaks.

Remaining Questions

(1) What and where does the "Fuel Return Line" [#16126752189] connect to? Realoem's diagrams do not show the connection point.

(2) (a) In the event that I remove the fuel rail as opposed to the blind approach... do you have any suggestions for the fuel rail removal? On the A1- Auto video they sprayed a non-silicon substance to help release the injectors. (b0 Will WD-40 be appropriate to use to help facilitate the fuel rail removal?

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Discoveries
(1) Fuel line return in the realoem drawing is incorrect. It does not connect in the engine bay rather at the fuel filter/regulator; it is a hard line.

(2) Below I will describe the problem analysis; I did not use any lubrication for the fuel rail removal. I did use a thin coat of oil on the top injector o-ring to facilitate re-installation of the fuel rail

Leak Background
2005 BMW 330CI Convertible (ZHP)
When the fuel filter was replaced in August 2021, the ring clamps were re-used on the transition rubber hoses (new hoses installed) connecting the hard lines to the fuel filter.

Root Cause
The leaks were on both rubber hoses around the 4 ring clamps. Upon installing new fuel injection ring clamps (non-BMW) ... no leaks were observed. The ring clamps were likely original and may be one use clamps. Never-the-less, they have been replaced. I went ahead and replaced the rubber quick-connect fuel line to the fuel rail.

Removal Process Comments
(1) I removed the fuel rail from the injectors ... replaced the top o-rings ... pulled the fuel rail to expose the quick connect and just pushed on it to release; no special tools required!
(2) I had read a step by step process for fuel rail removal which stated that only one side the the electrical harness metal clips needed to be released. I tried that but it would not release; therefore both sides of the clips were released and one could progressively wiggle and remove the fuel rail.
(3) One does need to have a telescopic magnet to retrieve errant electrical harness clips or fuel rail bolts.
(4) The clips holding the fuel line vertically are a pain to release, especially the one near the starter but it just spreads to release the line, the other connection points were simply friction fits.

No pictures because they would be of no value. It's more about the parts and process.

Good that's sorted.

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