Gas cap off, won't crank or start

[ilivetoserve]

Need your opinion please,
Went to start my 2001 525i, all I got was a "clicking" sound when I turned the key. Panel lights may have seemed a little dim, but maybe not. Tried the key a few more times; same thing. Thinking I had a dead battery, I had my neighbor give me a jump. While connected with the jumper cables, still just got "clicking" while turning the key; panel and running lights were very bright.

Immediately after disconnecting the jumper cables, I noticed that I had neglected to put my gas cap back on after I had filled up the tank the night before. I replaced the gas cap and tried the key again---Bingo ! started right up.

That was three days ago and I have not had a problem since then. Question: was the missing gas cap the problem or do I have short somewhere in my ignition system? If it was the gas cap, why did it start OK when I left the gas station with it "off" the night before?

Thanks!

[killcrap]

a gas cap will not impair your ability to start the vehicle it is just a conincidence. most likely the battery is truly dead, and you need to leave the cables connected longer.

[ilivetoserve]

OK, thanks for the info......so a "jump" will not instantly provide power to the vehicle with the dead battery?... if the vehicle does not immediately start, leave the cables connected for a couple of minutes?....is that correct?

[thejlevie]

If the battery is really low the donor vehicle make have to remain connected for 10 minutes or more before you can sucessfully start the car. This is especially true if you have the run of the mill jumper cables that have small conductors. Heavy duty cables (those with conductors 3/8" or larger) will start the car almost immediately.