View Single Post
Old 01-06-2012, 01:47 AM
we350z's Avatar
we350z we350z is offline
Join Date: Apr 2007
Location: West Coast
Posts: 1,705
we350z is on a distinguished road
Thanks guys:

@Dan Fowler - definitely agree that the X5 E53 (and BMW's in general) are power hungry with all the accessories they are running. On top of that I am powering a 300W RMS MTX Thunder 5302 sub woofer amp, Umnitza Predator Chromium V2 Angel Eyes, Scosche Bluetooth adapter, V1 Radar Detector, and a Phone Dock. No light load. To my knowledge the alternator has never been replaced and I am at 84,500 miles. I will have to double check the service records to be sure.

@BrianX54.4is - Interesting - it had crossed my mind perhaps the battery itself was the issue since the starting has become more lethargic and the the recent "click" when trying to start. I agree with your thought process about switching out the battery first. It's not reasonable to expect more than 4 years out of the battery, especially with abuse. It has been almost 4 years since I replaced the battery last. Eventually the cells are going to be damaged and the CCA's will decrease. Even after charging (supposedly to 100 percent, but I don't trust the digital readout on my charger) the cranking didn't seem that strong when starting the car. Excessive battery hasn't really been a problem. I have even taken steps to prevent battery drain completely by installing a Battery Brain (see my post on this). What points are you testing the current draw from? I do know that If I let my car sit for 3-4 weeks without the battery disconnected there is a good chance the battery will be (near) dead.

@RickM5X3 - I do know about the OBD diagnostic menu (my ScanGuageII does the same thing). I should check that it is consistent with the guage but I would be really surprised if it was. I'm going to get a new battery and monitor.

Thanks for the suggestions guys - totally no harm in trying a new battery and avoiding significant cost and labor. Worst case scenario is that I spend $100 or so on a new battery that I didn't really need :-) If it fixes the problem that is great if not the alternator replacement job is very doable.

Indy Shops:

German Auto Sport

Babbitt Motor Werks | Arizona Bimmer Motor Works

Reno Rennsport

00 BMW X5 4.4
93 Nissan 300ZXTT
88 Nissan 300ZXT Shiro #853
88 Nissan 300ZXT Shiro #773
84 Nissan 300ZXT 50th AE
78 Datsun 280Z Black Pearl
15 Yamaha WR250R
06 Yamaha R1 AE

WE350Z at gmail

Last edited by we350z; 01-06-2012 at 02:33 AM.
Reply With Quote

Sponsored Links