Need some help please

[SHkater]

Hey guys! My dads e39 528i had some startin problem today for some reason. My dad s been out of the country for almost a month and half now so the car hasnt been driven much me and mom take it out every now and then but we dont run it much. Anyways when i tired to start it the first time today, as soon as the engine started it shut off immediately for some weird reason and then after that i couldnt start it at all.. There was just some knocking sound whenever i turned the key but which doesnt sound like ignition at all :dunno:. A Neighbour came and said it was the battery so we connected the jump starter cables and the sound was still there we had to start the car of neutral. Anyways after we staretd it i tried revving it a few times and i felt like there is some kind of lag in throttle response. We drove the car afetr that alhamdulillah no problems. I hope its nothin serious.

[mahmoud_bedewi]

the knocking sound was like a high frequency "tic tic tic tic "?
if yes, the battery was dead
all the above symptoms r normal now wat u need to do in order to avoid this is to take the car to the highway every now and then and drive for an hour or so to allow the dynamo to work properly and recharge the battery

[SSense]

When was the last time the fuel filter was changed ? If fuel filter is fine and you can hear the fuel pump on ignition, then looks like it could be your CPS..

[SHkater]

the knocking sound was like a high frequency "tic tic tic tic "?
if yes, the battery was dead
all the above symptoms r normal now wat u need to do in order to avoid this is to take the car to the highway every now and then and drive for an hour or so to allow the dynamo to work properly and recharge the battery

Mahmoud the sound is not high pitched its more like tac tac tac and its commin from somewhere under the hood i guess but that high pitched beeping sound came after i switched the car on

When was the last time the fuel filter was changed ? If fuel filter is fine and you can hear the fuel pump on ignition, then looks like it could be your CPS..

My dad services the car every 10 k kms and it hasnt been driven much ever since he serviced it so i doubt its the filter.. What is is CPS?:D

[SSense]

My dad services the car every 10 k kms and it hasnt been driven much ever since he serviced it so i doubt its the filter.. What is is CPS?:D

Crankshaft Position Sensor, its responsible for most of the cases of engine misfire..

[SHkater]

Hmm i think my dad replaced the camshaft sensor around 3-4 months ago cuz he said there was some lag in throttle response.. The weird thing is we could only start it from Neutral today. What u are talkin about is the CRANKSHAFT sensor tho not CAMSHAFT right?

[mahmoud_bedewi]

Mahmoud the sound is not high pitched its more like tac tac tac and its commin from somewhere under the hood i guess but that high pitched beeping sound came after i switched the car on

i meant high frequency not pitch, anyway it is not even accurate to say it is high frequency
but "tic" or "tac" seems like we are talking about the same thing even the high beeping confirms the idea of dead battery
u mentioned neutral more than once, what did u try in the others attempts ? which position?

[SHkater]

i meant high frequency not pitch, anyway it is not even accurate to say it is high frequency
but "tic" or "tac" seems like we are talking about the same thing even the high beeping confirms the idea of dead battery
u mentioned neutral more than once, what did u try in the others attempts ? which position?

We tried starting from parking as usuall but it wouldnt, just started off Neutral once and that was it

[mahmoud_bedewi]

i am not sure about this but my analysis is as follows, the load on the starter motor could b less when u use N than when u use P so since the battery was dead the decrease in load made it easier to start
i guess if u used the other battery directly u could have started in P (happened to me before)

[SHkater]

Thanks guys! The car's been running well the last week no problems alhamdulillah. I guess it was the alarm that killed the battery, it sets off daily at random times for a weird reason..

[SewerSideUp]

Dude, just start it on a daily basis to keep the battery's juice fresh. Start the car, let it idle for atleast 5 minutes, wait for the temp needle to move minimum to the quarter mark. Rev the engine smoothly, but don't jump on the throttle or rev it high. Drive it as much as you can, battery deaths can cause electrical issues later. If you get to jump start her again, use a car with a 6 cylinder engine minimum. Other than that, she should be fine.