BMW X5 E53 3.0d 2004 : Intermittent Starting Problem
Discussion
Hi Everyone
I have an aging BMW X5 E53 3.0d 2004 which has recently been difficult to start the engine.
Whenever I turn on the ignition, the engine would crank but would not start.
I would then repeat the process more than 10 - 20 times but to no avail.
But when I turn on the ignition and could heard a humming noise coming from under the car, the engine would start every time. If I were to it turn off and on again, the engine would start again.
However, when the car is left turned off for more than a couple of minutes, the problem would start again.
I have progressively replaced the following parts by to no avail:
1. the pump relay;
2. the glow plug control unit;
3. the pre supply pump;
Would appreciate any tips from the forum.
Any ideas anyone?
Regards
Tony
I have an aging BMW X5 E53 3.0d 2004 which has recently been difficult to start the engine.
Whenever I turn on the ignition, the engine would crank but would not start.
I would then repeat the process more than 10 - 20 times but to no avail.
But when I turn on the ignition and could heard a humming noise coming from under the car, the engine would start every time. If I were to it turn off and on again, the engine would start again.
However, when the car is left turned off for more than a couple of minutes, the problem would start again.
I have progressively replaced the following parts by to no avail:
1. the pump relay;
2. the glow plug control unit;
3. the pre supply pump;
Would appreciate any tips from the forum.
Any ideas anyone?
Regards
Tony
It sounds like you are describing the noise of the fuel pump running as the hum you hear when it starts, which says to me that the issue is that the car will not start when the fuel pump isn't running, which is as you would expect, there is no fuel, so why would it.
You say you have changed the pump & the relay, unfortunately that appears to have been money down the drain, as was the glow plug.
What you need to do is to chase the electrical wiring etc between ECU/Relay & pump when the fault is present, it sounds like you either have a problem meaning the pump isn't being started by the ECU, which could lead you elsewhere or you have a wiring issue in the area described.
You say you have changed the pump & the relay, unfortunately that appears to have been money down the drain, as was the glow plug.
What you need to do is to chase the electrical wiring etc between ECU/Relay & pump when the fault is present, it sounds like you either have a problem meaning the pump isn't being started by the ECU, which could lead you elsewhere or you have a wiring issue in the area described.
The inline pumps used to stop and start working randomly so the fact it was sometimes buzzing and sometimes new not indicates it probably was defective.
You could do with gettin someone to check fuel rail pressure when it’s not starting- it could be fuel injectors leaking off stoping the pressure reaching 200bar hence it will never attempt to fire till it does reAch that pressure. It’s easy to check leak off with a bit off tube, a bottle and a pipe clamp or pair of grips. I think it shouldn’t leak more than 60 millilitres within a minute when the engine is running or turning over
You could do with gettin someone to check fuel rail pressure when it’s not starting- it could be fuel injectors leaking off stoping the pressure reaching 200bar hence it will never attempt to fire till it does reAch that pressure. It’s easy to check leak off with a bit off tube, a bottle and a pipe clamp or pair of grips. I think it shouldn’t leak more than 60 millilitres within a minute when the engine is running or turning over
My gut feeling is it is probably injector leak off, but you could do with getting the faults read to confirm it’s a low fuel pressure issue.
Injectors leaking off will only cause starting issues as when it’s running it can get up to pressure much easier as engine is turning over quicker
Injectors leaking off will only cause starting issues as when it’s running it can get up to pressure much easier as engine is turning over quicker
That engine is in hundreds of thousands of BMW models and that is one of the most common faults I've heard of
What do the diagnostics say? You can get to the bottom of most faults on BMWs of that era by checking
Cam and crank position sensors are a common reason for this failure, as is the low-pressure fuel pump. Also if it has a saddle tank like the 5-Series touring then it may not be picking up fuel when it gets below 1/4 tank
Nick Froome
What do the diagnostics say? You can get to the bottom of most faults on BMWs of that era by checking
Cam and crank position sensors are a common reason for this failure, as is the low-pressure fuel pump. Also if it has a saddle tank like the 5-Series touring then it may not be picking up fuel when it gets below 1/4 tank
Nick Froome
bolide said:
That engine is in hundreds of thousands of BMW models and that is one of the most common faults I've heard of
What do the diagnostics say? You can get to the bottom of most faults on BMWs of that era by checking
Cam and crank position sensors are a common reason for this failure, as is the low-pressure fuel pump. Also if it has a saddle tank like the 5-Series touring then it may not be picking up fuel when it gets below 1/4 tank
Nick Froome
X5 is the same, the transfer pump arrangement is crap, try putting a half tank in it to diagnose.What do the diagnostics say? You can get to the bottom of most faults on BMWs of that era by checking
Cam and crank position sensors are a common reason for this failure, as is the low-pressure fuel pump. Also if it has a saddle tank like the 5-Series touring then it may not be picking up fuel when it gets below 1/4 tank
Nick Froome
On the 5-Series there is no transfer pump, it uses the Bernouilli effect to pick up fuel from the far side of the tank and drag it over to the side with the pump
The two assemblies in the tank are the wierdest, most complex things I've ever seen
Unless the pump is toast (highly possible) I'd recommend leaving them well alone and keeping > 1/4 tank in it at all times
Nick Froome
The two assemblies in the tank are the wierdest, most complex things I've ever seen
Unless the pump is toast (highly possible) I'd recommend leaving them well alone and keeping > 1/4 tank in it at all times
Nick Froome
Thank you Nick, Elliot2000. E-BMW for the tips.
There are plenty for me to think about.
By the way, I have recently purchased a Carly for BMW Pro app and their Carly ODBC plug to try and diagnose my crank no start problem.
Unfortunately, I haven't seen any meaning diagnostics yet.
Is anyone using the Carly app and connector?
Regards
Tony
There are plenty for me to think about.
By the way, I have recently purchased a Carly for BMW Pro app and their Carly ODBC plug to try and diagnose my crank no start problem.
Unfortunately, I haven't seen any meaning diagnostics yet.
Is anyone using the Carly app and connector?
Regards
Tony
bolide said:
That engine is in hundreds of thousands of BMW models and that is one of the most common faults I've heard of
What do the diagnostics say? You can get to the bottom of most faults on BMWs of that era by checking
Cam and crank position sensors are a common reason for this failure, as is the low-pressure fuel pump. Also if it has a saddle tank like the 5-Series touring then it may not be picking up fuel when it gets below 1/4 tank
Nick Froome
You can hopefully rule out cam and crank sensors, Dde relay, immobiliser issue or anything like that as he said the car starts up straightaway on easy start. It just seems to be struggling to raise the fuel pressure high enough on cranking for it to be able to decide to start injecting - fuel supply does seem to be the issue. It would be good to narrow down between high pressure or low pressure side.What do the diagnostics say? You can get to the bottom of most faults on BMWs of that era by checking
Cam and crank position sensors are a common reason for this failure, as is the low-pressure fuel pump. Also if it has a saddle tank like the 5-Series touring then it may not be picking up fuel when it gets below 1/4 tank
Nick Froome
If you can get Carly to work then afaik you can readout the high and low fuel pressure reading which will give you a clue - with ignition on but not cranking it should be roughly what the low pressure should be on both sensors which I think is around 4 bar?! And then whilst cranking the hp sensor should go straight to 180 or 200bar
If you can read the low fuel pressure sensor - compare it with the high pressure sensor with just ignition on - if there is a noticeable difference between the two it’s likely the high pressure fuel sensor has gone funny.
If it slowly builds up to around 200 bar after a while of cranking then it’s probably injectors leaking off.
If it stays very low - below 50 bar then it’s probably the volume control valve stuck open or the hp pump.
bolide said:
On the 5-Series there is no transfer pump, it uses the Bernouilli effect to pick up fuel from the far side of the tank and drag it over to the side with the pump
The two assemblies in the tank are the wierdest, most complex things I've ever seen
Unless the pump is toast (highly possible) I'd recommend leaving them well alone and keeping > 1/4 tank in it at all times
Nick Froome
The x5 is tbe same I wanted to call it a venturi driven pump but I knew that wasnt right. Whatever it is its a bag o sThe two assemblies in the tank are the wierdest, most complex things I've ever seen
Unless the pump is toast (highly possible) I'd recommend leaving them well alone and keeping > 1/4 tank in it at all times
Nick Froome
te and fails frequently, but with more than half a tank its fine. First one swapped one from a scrappy, on my mates one found a split pipe that was drawing air.Gassing Station | BMW General | Top of Page | What's New | My Stuff