Really wierd start-up symptoms

[85k100rt]

It's turned cool now here in Las Vegas (60 F) and on two mornings at first start, strange indications from the dash error display. The first morning, it was an error message that I've never seen and I just hit reset and everything cleared and drove as normal. All subsequent starts that day were normal. The next morning at first start, my speedometer showed I was cruising at about 80mph and about 5500 rpm along with another strange error message. This immediately cleared with the reset button and everything was normal. For three days running now, this hasn't repeated itself. I'm guessing it's time to have the battery checked and replaced. Anyone have a better idea?

[Pelican Parts]

Do you remember what the error message said? Did you also get a CEL?

[shogun]

Check the battery first, but under load, other tests are not giving reliable results. I have one of these cheap HF battery load testers, 2 big clamps and a unit with indicator, push a button for a short time, unit get;s hot and you see immy what the state of the battery is. If the battery is low, you get any kind of electr. issues Load Testing A Battery - Eric The Car Guy https://www.youtube.com/watch?v=3QiKyjWWiRo

if that is o.k., cluster caps http://bmwe32.masscom.net/johan/dash...dash_caps.html
if that is o.k., resolder the CCM , see especially page 8 http://www.e34-welt.de/tips_tricks/R...0e34%20e32.pdf

[85k100rt]

Stopped by a local parts store to get the battery load tested. Indication was "battery is marginal, s/b replaced soon" when checking under the hood. Had battery replaced with Bosch, now tests "good". Finding a BCI 93 battery for this vehicle is virtually impossible here in Las Vegas. Interstate has MTP 93/T8 (6 year warranty), but not stocked in Las Vegas Interstate distributor. They are available in Utah and Arizona via Interstate's Distribution service, but that takes time and is very expensive. Hopefully, problem is solved. Thank you........

[shogun]

fits on 750iL: Super Start Extreme - Battery, Line: SSB | Part # 93EXT, 3 Year Limited Warranty, UPC: 83996196070, Group Size (BCI): 93, Cold Cranking Amps (CCA): 800 CCA, Cranking Amps (CA): 985 CA, Voltage (V): 12 Volt,
Length (In): 13-5/16 Inch, Width (In): 6-7/8 Inch, Height (In): 6-7/8 Inch, Compability: fits: 750iL Base, V12 - 5.0L 4988cc type M70 - 1988 - 1994 , from O'Reilly Auto parts website copied
pics installed http://www.bimmerboard.com/forums/posts/1263184