VCG changed, now have parasitic drain on battery

Red_Tears · 10-07-2019, 08:30 AM

Changed my VCG over the weekend as well as the OFHG, now I continue to get dash display cutoff errors in my KOMBI module, and low battery charge light on the dash. The coolant temp sensor is stuck showing the car is overheating, running my WP in overdrive and kicking the fan into it's max setting. My current hypothesis is that sensor is now grounded out, however I don't understand how that would discharge my battery once the car has shut off, unless in "sleep" mode those sensors are still powered?

If any of you have other ideas, happy to learn.

Also, I changed the oil while I was at it (obviously) and now I have crazy loud lifter tick, changed it with Castrol 5w-40 full synthetic, rated for BMW LL-01. Any advice here would be appreciated as well.

Thanks,

-R

pwner4once · 10-08-2019, 08:47 AM

I had a similar experience when I replaced my VCG / OFHG as well.
I disconnected the neg terminal before the job.
Afterwards, I had to keep jumping the battery to start car started.

Turns out the battery was just on its way out (1yr battery AGM autozone...)

For your issues, the lifter tick kicks in when my car haven't been driven in a while.

The coolant temp sensor... what happens when you unplug it?
If a default mapping kicks in and the car runs fine, then it confirms your hypothesis. Otherwise, it's something else.

10-07-2019, 08:30 AM	#1
Red_Tears New Member 7 Rep 27 Posts Drives: 2008 BMW 335i Join Date: Sep 2019 Location: Central US iTrader: (0)	VCG changed, now have parasitic drain on battery Changed my VCG over the weekend as well as the OFHG, now I continue to get dash display cutoff errors in my KOMBI module, and low battery charge light on the dash. The coolant temp sensor is stuck showing the car is overheating, running my WP in overdrive and kicking the fan into it's max setting. My current hypothesis is that sensor is now grounded out, however I don't understand how that would discharge my battery once the car has shut off, unless in "sleep" mode those sensors are still powered? If any of you have other ideas, happy to learn. Also, I changed the oil while I was at it (obviously) and now I have crazy loud lifter tick, changed it with Castrol 5w-40 full synthetic, rated for BMW LL-01. Any advice here would be appreciated as well. Thanks, -R
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10-08-2019, 08:47 AM	#2
pwner4once Enlisted Member 4 Rep 40 Posts Drives: BMW 328i Coupe / 07 Join Date: Jan 2012 Location: Dallas, Texas iTrader: (0)	I had a similar experience when I replaced my VCG / OFHG as well. I disconnected the neg terminal before the job. Afterwards, I had to keep jumping the battery to start car started. Turns out the battery was just on its way out (1yr battery AGM autozone...) For your issues, the lifter tick kicks in when my car haven't been driven in a while. The coolant temp sensor... what happens when you unplug it? If a default mapping kicks in and the car runs fine, then it confirms your hypothesis. Otherwise, it's something else.
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