E39 530i intermittent non start
Discussion
Finally got round to getting an MOT on my e39 after it has sat on the drive for the last 2.5 years. Flew through the MOT but when I got to the garage it wouldn’t restart when the mechanic got in to put in on the ramp. Turned over strongly and had spark but couldn’t hear the fuel pump running.
Started after a few minutes and ran perfectly for the test and drive home. It then did the same thing a bit later when I went to start it- turned over but no start. Didn’t hear fuel pump prime.
I’ve just tried it again this evening and it started first time. So I think there’s a couple of possibilities. Fuel pump, fuel pump relay or crank sensor.
Does anyone know where the fuel pump relay is located in a 2003 530i? And what’s the best way to test the crank position sensor?
Annoying that now it’s finally legal to drive I can’t as I don’t know if it will start again at the other end of the journey!
Started after a few minutes and ran perfectly for the test and drive home. It then did the same thing a bit later when I went to start it- turned over but no start. Didn’t hear fuel pump prime.
I’ve just tried it again this evening and it started first time. So I think there’s a couple of possibilities. Fuel pump, fuel pump relay or crank sensor.
Does anyone know where the fuel pump relay is located in a 2003 530i? And what’s the best way to test the crank position sensor?
Annoying that now it’s finally legal to drive I can’t as I don’t know if it will start again at the other end of the journey!
Yea that’s all fine was done a few years ago. While it was off the road I changed the sump gasket, found and fixed some vacuum leaks and cleared out the dipstick tube (the double walled bit at the bottom), replaced the injector seals and the rubber intake pipes between the maf and throttle body so there’s definitely no issues on that side of things.
Reading up about it I’m convinced it’s the fuel pump. It ran when we sprayed some ether down the intake so it’s got spark when theres no fuel.
When I was driving it the engine felt spot on- idle was rock solid and it pulled nicely, no flat spots.
Reading up about it I’m convinced it’s the fuel pump. It ran when we sprayed some ether down the intake so it’s got spark when theres no fuel.
When I was driving it the engine felt spot on- idle was rock solid and it pulled nicely, no flat spots.
Both cam sensors were replaced in my ownership with genuine bmw which cured a stumble coming off idle when hot.
Could hear the pump prime (subtle hum for a couple of seconds) when it started when cold.
It ran on starter fluid when it wouldn’t start at the garage which apparently they wont do when the crank sensor is playing up as the ecu won’t fire the ignition.
Could hear the pump prime (subtle hum for a couple of seconds) when it started when cold.
It ran on starter fluid when it wouldn’t start at the garage which apparently they wont do when the crank sensor is playing up as the ecu won’t fire the ignition.
So new development, all the lights decided to turn on this morning and not turn off unless I disconnected the battery. Presumably a LCM issue.
I gather replacement involves coding the mileage into the LCM but it has to be an LCM that has a lower mileage on it than the car? Which might be hard to find as mine has only got 98k miles on.
Any recommendations for repair places?
I gather replacement involves coding the mileage into the LCM but it has to be an LCM that has a lower mileage on it than the car? Which might be hard to find as mine has only got 98k miles on.
Any recommendations for repair places?
When I removed it there was no corrosion or water damage etc. all looked perfectly clean. Sent it to a guy in Harrogate who has a business called Autoelectron. Found a decent amount of positive feedback online for him fixing various different electronic modules and roof mechanisms for BMWs, Land rovers etc.
He repaired the module for £70 and had it sent back the same day.
He repaired the module for £70 and had it sent back the same day.
Just waiting on a fuel pump as they were on back order from Bosch. (Bosch apparently are partners with TI Automotive/Walbro who are the OEM). They're due early April, so fingers crossed. I only want to do the job once and not in a rush so went with a new one rather than second hand.
As a side note it's so annoying all these places that list things as being in stock on their websites but in reality they just don't ever update anything, so you order it and a few hours later you get an email saying they don't actually have it. Seems like it happens for most things I order for this car now.
As a side note it's so annoying all these places that list things as being in stock on their websites but in reality they just don't ever update anything, so you order it and a few hours later you get an email saying they don't actually have it. Seems like it happens for most things I order for this car now.
Got all the bits. LCM swapped back in and all lights work fine, scored a genuine new crank sensor for £40 on ebay so swapped that once i realised how easy it was to get to.
Doing the fuel pump related bits now. Can't for the life of me find the fuel pump relay. It's not up behind the glove box, have had all that out and the only relay there is for the horn. Dropped the cream plastic carrier down which contains two modules and a junction box and there are no relays above it.
There are two green relays on the fuse box above the battery. Removing both of these does not stop the car from running. Think they are for the heated rear screen and parking sensors possibly.
Am now stumped.
Doing the fuel pump related bits now. Can't for the life of me find the fuel pump relay. It's not up behind the glove box, have had all that out and the only relay there is for the horn. Dropped the cream plastic carrier down which contains two modules and a junction box and there are no relays above it.
There are two green relays on the fuse box above the battery. Removing both of these does not stop the car from running. Think they are for the heated rear screen and parking sensors possibly.
Am now stumped.
Got it to replicate the no hot start issue. Could hear a relay ticking (have removed rear seat to hear/feel what fuel pump was doing). Fuel pump wasn’t priming.
Tracked the ticking down to the e-box under the near side pollen filter. There’s definitely a relay in there that isn’t latching.
Can’t get two of the bolts holding the lid of the box off though. The moulded in nuts are just spinning. Ffs
Tracked the ticking down to the e-box under the near side pollen filter. There’s definitely a relay in there that isn’t latching.
Can’t get two of the bolts holding the lid of the box off though. The moulded in nuts are just spinning. Ffs
Yes
Swapped fuel pump and although it seems to run smoother it still doesn’t start when it’s warmed up.
That blue relay clicks (I haven’t replaced that yet) and the gauges do this, lights on and temp gauge in red (it’s not overheated).
I think there is something more sinister going on.
When it’s running it’s perfect but there’s some issue that seems to be stopping the ecu coming on when the car is warmed up.
If you leave it 5-10 mins it will start and run fine.
Swapped fuel pump and although it seems to run smoother it still doesn’t start when it’s warmed up.
That blue relay clicks (I haven’t replaced that yet) and the gauges do this, lights on and temp gauge in red (it’s not overheated).
I think there is something more sinister going on.
When it’s running it’s perfect but there’s some issue that seems to be stopping the ecu coming on when the car is warmed up.
If you leave it 5-10 mins it will start and run fine.
Edited by lufbramatt on Thursday 18th April 15:18
Actually I think the clicking blue relay is the DME relay, still no idea where the fuel pump relay is but don’t think that’s the issue.
I found this:
https://m.youtube.com/watch?v=hk1HjL8PTRg
That’s the exact symptoms mine has. Looks like a possible DME issue.
I found this:
https://m.youtube.com/watch?v=hk1HjL8PTRg
That’s the exact symptoms mine has. Looks like a possible DME issue.
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