Project BMW M3: Setting Goals

Know what every successful project needs, no matter the scope or subject? A goal.

The goal for our 2004 BMW M3 is simple: We want to detail the ownership experience so the person eyeing an E46-chassis M3 on Bring a Trailer or eBay Motors can make a sensible decision. Does the reality match th…

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Psst - is  a supercharger legal....?

In reply to wspohn :

I guess?

Battery drain is killer. I solved it in my E36 by turning it into racecar. 

Jk don't ruin this haha. It is way too nice for any of that nonsense. 

Yeah, need to figure out the battery drain. 

I'm just going to put this here.

https://www.turnermotorsport.com/Search?No=0&Nrpp=50&Ntt=T%23586813+T%23586807&trk_msg=10G39SCN2JMK50U4G63GSBBSQO&trk_contact=FILD8INKUU6HS6NDPFBEL1QVQK&trk_sid=2C9NHRN2J4HDF4VOVLMBEQ4V9K&utm_source=emailcampaign&utm_medium=email&utm_term=https%3a%2f%2fwww.turnermotorsport.com%2fSearch%3fNo%3d0%26Nrpp%3d50%26Ntt%3dT%2523586813%2bT%2523586807&utm_campaign=TMS_Weekly_cool_upcoming_products_05172020_CW_MKT6

I want an e46 m3 so bad now just to own this intake. The sounds it must make.....

I had parasitic draw on my E36 M3 that was killing the battery on a weekly basis. I found that the cabin light settings were at least a partial root of the problem. If I had it set for all of the cabin lights to come on when opening or locking the doors it would kill the battery if I didn't drive it for a while. I still haven't gotten down into the nitty gritty of the problem but just having the switches set to off helped. 

Sometimes the hood switch will drain the battery as well.

or more common, trunk latch switch

My moms Acura RLX battery kept dying on a weekly basis like that. Since it was under warranty, she'd have it towed to the dealer so they could try to figure out what was wrong. One service writer asked me how far away the keys were stored when the car was parked in the garage (~10-15 ft). He said the car would sense the key fob and "wake up" and stay that way so it would be ready to start. The system wasn't smart enough to shut everything back down and go to sleep after a certain time went by with no activity, so the battery would run down. We started putting the key fob on the opposite side of the house from the garage, and problem solved. Could that be what's happening with your M3?

Thanks for the leads. This model still uses a key, so I doubt that's the issue–and there are several walls between the key and the car itself. 

Yeah, need to break out some diagnostic tool, dig into the GRM archives,  and investigate that one further.