So, I've been having some issues with my 2006 R53 starting. Original battery was still in there, so I had it tested and that appeared to be the problem, so I replaced it. A couple times now, car still won't start, but after I pop the hood, starts up like normal. Anyone had any similar experiences or any idea what is happening? Or is this just some strange coincidence?

 

Just a guess...maybe the grounds are iffy...and jiggling the car by opening the hood lets you start it...or maybe just an odd thing happening at the same time unrelated...i would check the ground though...pretty simple...and an oem battery that old was most likely pretty weak...

 

You might also want to check and make sure that when the hood is closed, it's not touching the battery terminals. Did you replace it with an identical OEM battery? If not, it may be slightly taller than the original battery.

 

Can't tell your region, OP, but as said, it has to be battery related. If it is getting cold where you are, and the battery is old, then get it tested(deep cycle).

I had a similar issue a while ago, but it was just a matter of snugging down the leads right at the terminals, a little jiggle was juuuuuuuuust enough to make things troublesome.

 

Gen1 S batts are in the trunk.
thought everybody knew that by now..lol

 

Last time I checked my battery was in the boot

 

Battery was replaced with an optima 34R, so at this point I know that's not causing the problem. After a more detailed inspection during daylight hours, I found a ground strap that goes from the hood to the rest of the car on the driver's side that looks like it might be getting pinched and could probably use replacing. I'm not really a wiring guru, so I don't know if it's possible that might have been causing it.... other grounds I could see looked fine, although I have not yet gotten under the car to look at anything there.

 

I can not fathom a scenerio where a bonnet ground strap could impact strarting.

the battery has a straight line to the starter (via the solinoid) and the block grounds to the body to return to the battery . . . . all the other body grounds are for the 'other stuff' hung on the car . . . .

If your problem is a ground it is probably in the battery .... I seem to recall a post several years ago talking about how the Optima post diameter was smaller than the OEM, and you could bottom out the cable (it feels tight) but it really was NOT tight against the post .. a shim was required. (I prefer all copper)