X5 3.0D E53 2005 Starting Problem

[Rexnest]

Hello all, First time poster so please excuse me if I've omitted any info required.
Every morning my car cranks but does not catch for a few attempts. After 3rd or 4th attempt it catches very quickly and runs / starts perfectly for the rest of the day.
I've only owned the car for 2 weeks and only started to have problems since we've had cold mornings. Car has 120,000 miles but no service history for last few years. Suspect battery / fuel pump relay or fuse / glow plug module, plug or fuse from reading earlier posts.
Any help on how to eliminate any of the possible causes (or any further possible causes) would be greatly appreciated.

[andrewwynn]

You have to explain "catch".

If you mean you turn the key and get "on" but no crank but after a few tries it starts normally, that is almost always the ignition switch failed.

[Rexnest]

Hi Andrew, thanks for the quick response. It does crank every time, but just keeps cranking ie does not start. After 3 or 4 attempts, it starts almost straight away after turning the key. I'm just a bit concerned as I know it is doing damage to my battery every time...

[andrewwynn]

Originally Posted by Rexnest

Hi Andrew, thanks for the quick response. It does crank every time, but just keeps cranking ie does not start. After 3 or 4 attempts, it starts almost straight away after turning the key. I'm just a bit concerned as I know it is doing damage to my battery every time...

Crank no start is different. Will it start if you continue to crank? It does seem a little like intermittent fuel pump.

Pull up your back seat (just lifts on the front edge) and with fan/ac and radio off listen for the fuel pump when you turn the key to on but not start.

It makes a very distinct whine/hum. It should last about 5 seconds and stop. You should always pause a couple seconds on "run" to let the fuel pump pressurize the system before cranking to get full pressure at the injectors.

If you don't hear the whine of the fuel pump then it's probably just that: when a fuel pump goes it can have a flat spot where it won't run but trying a couple times can get it past the flat spot. Once past the flat spot it'll run fine. (just at reduced power).

You can supply direct power to the pump by putting a jumper in the relay socket to rule out the relay and ECM sending the wrong signal.

[Delta2nineR]

I had the same issue for a while. It was my starter motor and once replaced starts like its a brand new car. Diesels require more amperage to start so common for starters to wear out quicker.


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[wpoll]

But until you get the codes read out, it's all guess work on our part.

[Rexnest]

Well, thanks for the replies guys. Came out to the car this morning after filling it up with fuel yesterday and it started up a dream, first time.
Not 100% sure if it's because it was slightly warmer today (8 deg rather than 3 deg) or if the additional fuel made the difference but i'm glad one of the 2 things seems to have 'fixed' it. At least it narrows down the list of possibilities.
I have since read that there is a common problem with X5's struggling to start with less than 1/4 tank of fuel... Does anybody know the reasons for this?
I'm hoping to get the codes read this weekend so should know a bit more then.

[wpoll]

Originally Posted by Rexnest

Well, thanks for the replies guys. Came out to the car this morning after filling it up with fuel yesterday and it started up a dream, first time.
Not 100% sure if it's because it was slightly warmer today (8 deg rather than 3 deg) or if the additional fuel made the difference but i'm glad one of the 2 things seems to have 'fixed' it. At least it narrows down the list of possibilities.
I have since read that there is a common problem with X5's struggling to start with less than 1/4 tank of fuel... Does anybody know the reasons for this?
I'm hoping to get the codes read this weekend so should know a bit more then.

It sounds like you may be seeing a siphon pump failure in your fuel tank left-side sender/siphon.

Do you know much about the fuel tank system in the E53? If not, read this...

https://xoutpost.com/bmw-sav-forums/...stic-help.html

There's specific info. on the siphon pump repair here...

https://xoutpost.com/bmw-sav-forums/...iy-repair.html

Before tearing into the tank, you can check the siphon operation via the hidden BC menu #6 - check that both senders are working first (via menu#6.3 - look for Phase 1) then follow andrewwynn's advise on watching the left and right fuel levels as the tank empties below a 1/4 full.

I've not heard of this problem on the diesels (different fuel - obviously) but I guess it's possible.

Easy fix if that's your problem!

[andrewwynn]

I was just about to paste the link when I refreshed and wpoll beat me too it.

Short version: design flaw causes a leak in the siphon pump usually between 100-130,000 miles and when it starts to leak you will stall out of gas with initially 10-20 miles to empty but slowly that will rise up to maybe 70-80 miles to empty.

Hidden menu 6 will provide proof positive if the siphon pump is not doing its job. Replacing the o-ring and propping up the connection will prevent it from leaking in the future.

If siphon jet isn't leaking yet, proper placement of a simple zip tie will prevent it from failing in the first place.


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[wpoll]

Originally Posted by andrewwynn

I was just about to paste the link when I refreshed and wpoll beat me too it.

You ARE the word - I'm just an echo!

Originally Posted by andrewwynn

If siphon jet isn't leaking yet, proper placement of a simple zip tie will prevent it from failing in the first place.

Guess what I'm going to do this weekend....