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E46 Electrical bug

Posted: Thu Dec 24, 2009 2:01 pm
by Royalratch
I have a 2003 320d SE Touring.

I have retrofitted:

BMW Xenons (but draws less voltage)
Power & Heated Memory Seats (fitted with proper BMW looms and at fusebox)
Parrot Bluetooth Kit (fitted properly at fusebox)
iPod adapter (fitted properly at fusebox)
AC Schnitzer engine tuning module (draws minor current direct from battery)

I have noticed now and again my head unit (BMW Professional with bigger onboard amp) would just switch off for a few seconds. I thought this was just a random glitch.

However, I noticed when I try to lower two windows simultaneously as a crude 'current load' test, my Xenons flicker, random lights flash up in the clocks and the head unit switches off.

My guess is, I am overloading my battery or my alternator or both. I never have a flat battery and all is fine normally.
Anyone with solid electrical knowledge or called Brianmoooore care to have a guess?

Re: E46 Electrical bug

Posted: Sat Dec 26, 2009 9:47 am
by Royalratch
I get it okay - it's Boxing Day I know...

Re: E46 Electrical bug

Posted: Sun Dec 27, 2009 11:48 am
by Royalratch
Chump.

Re: E46 Electrical bug

Posted: Sun Dec 27, 2009 1:58 pm
by Andyboy
Sod the electrical niggles - get the manifold flaps removed NOW! All 150bhp 320d's have them and when (no 'if' about it) one comes loose, it's bye bye engine.
It's not a massive or expensive job, but it's a lot less than another engine.

Re: E46 Electrical bug

Posted: Sun Dec 27, 2009 2:02 pm
by kieran325
Andyboy wrote:Sod the electrical niggles - get the manifold flaps removed NOW! All 150bhp 320d's have them and when (no 'if' about it) one comes loose, it's bye bye engine.
It's not a massive or expensive job, but it's a lot less than another engine.
How can this be done done ?? I've got a 2004 E46 320d 150bhp.

Re: E46 Electrical bug

Posted: Sun Dec 27, 2009 2:18 pm
by stuartgallafant
Racth, you're overloading the battery. The battery in yours is probably an 80 or 90Ah battery, with 570CCA. For all the things you've retrofitted, regardless of doing them uber-properly, there is a much greater demand for power, which the battery simply cannot provide.

If possible, go for 100 or 110Ah, you may find the alternator needs changing too. If you're unsure, find a vehicle with an extremely close spec. to yours, identical if possible, and cross reference any charge/battery details using the other chassis number. Batteries bought directly from BMW will not cost you much more than anywhere else, and they really are the nuts!

Andyboy, does taking the manifold tract flaps out not make the engine run like a bag of brown stuff?!

Re: E46 Electrical bug

Posted: Sun Dec 27, 2009 2:25 pm
by Royalratch
Cheers Stuart, I suspected as much.

@ Andyboy, I know all bout the swirl flap issue in the manifold. My engine was replaced because of this very failure and thus I have 40K engine and turbo! :D. It has the newer style manifold with a plastic jacket around the swirl flaps and they also run on fatter spindles. Removing the swirl flaps actually improves torque but gives a slightly higher smog output on cold startup.

@ Kieran325 - you can either remove the manifold yourself, remove the swirl flaps and fit blanking screws or you can go to PMW in Peterborough who have ready made blanking plugs and can fit for £150-£200. You should also change your crank breather (£40 from BMW) and remove the EGR valve and either clean or eliminate it and fit the hollow bypass version - this stops the lame BMW emissions short cut of recirculating exhaust gas into your engine.

Re: E46 Electrical bug

Posted: Sun Dec 27, 2009 9:08 pm
by Royalratch
Interesting info.

320d batteries are offered by BMW in 70ah, 80, 90ah and 95ah.
320d Alternator is single model, 150ah.

330Ci batteries are offered only in 70ah and 80ah.
330Ci Alternator is 90ah and 120ah.

I'll check how large my battery is - hope the alternator rating is visible somehow.

Re: E46 Electrical bug

Posted: Mon Dec 28, 2009 9:19 pm
by Ali-bumble
My E46 330D uses a 150ah alternator, it also has a 110ah battery HTH

Re: E46 Electrical bug

Posted: Mon Dec 28, 2009 9:33 pm
by Royalratch
It's a D too. I don't understand why Diesels need more juice.

Re: E46 Electrical bug

Posted: Tue Dec 29, 2009 6:58 pm
by stuartgallafant
Possibly to keep the glow-plugs on whilst cranking and warm-up. I did think that alternator was a single rating, but couldnt fully remember

Re: E46 Electrical bug

Posted: Tue Dec 29, 2009 7:08 pm
by bss325i
Royalratch wrote:It's a D too. I don't understand why Diesels need more juice.
Diesel engines have a higher compression ratio and need more power to crank them over.