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Electrical shutoff while driving.... help.

5K views 35 replies 11 participants last post by  nae36 
#1 ·
And even more problems with my "ultimate driving machine." So heres the issue, when I'm driving my 2001 330ci sometimes the power will randomly cut, not the engine but all of the electrical stuff and all of my lights light up (oil, battery, dsc, brake, check engine, etc). I turn the key off and on and everything is fine and I drive away. I also have a crack in the radiator, so at first I thought "its spitting collant onto the connections for my angel eyes." Taped everything off with friction tape and E tape, and it just happened again. What could be causing this? I'm getting about 14 volts from the battery when the cars on so I don't think its the alternator or could I be wrong? I already have to fix a radiator but I dont have the time. Is there anyone who could help me out here?
 
#3 · (Edited)
Fix your leaking cooling system, check your battery connections, and clarify what's going on...it's cutting off while you're moving, and you cycle the key (while still moving) and it is fine...or when you lose power, you pull over, and restart the car and it's good?

Could be a loose cable on battery--pull up on the clamp to make sure...look into the bst connection too.

In any case, coolant on belts will affect voltage in that the alt belt could slip...as would the PS pulley...and if your wp is slipping, combined with a leaking radiator, you could be in for a world of hurt and payments for large repairs.

I suspect that maybe you have a bad pulley that's seizing and coolant on belts...which would cause belt to stop at times...no power, no steering, no wp.

You need to stop driving it and fix it. Sorry.

Oh, and if you don't DIY yet, either learn or maybe try your regional forum to see if someone can help you with this stuff. You have some great enthusiast mechanics out there...see if you're close to either Cyberkaa or e46Mango
 
#5 ·
Good thinking. Use good flashlight, read up on stuff, plan your work and work your plan.

While at your cooling system, read Mango's sticky and if you have the money, do it all and don't worry about the cooling system for years (except for periodic drain/refill).

Remove belts, turn pulleys...if you're lucky, one won't be turning so well. Replace all three if you find one bad...search 'pulley' in thread title.

Also, your radiator may be leaking, or it could be ET, ET cap, bleeder screw, failed hose. Radiator usually leaks between black sidepod and aluminum...there's a gasket in between (unsericeable). It will sometimes crack at the neck where the upper hose fits, but not too often I don't think.
 
#8 · (Edited)
No need for anybody else here.

This thread is well looked after with Dmax:thumbup:

+1 on the battery connections, pull up on them to be sure they're nice and snug, if you're battery isn't secure, it could shift just enough to wiggle the possibly loose connections, and cause temporary loss of power/brownouts, on braking, and acceleration.

GL.
 
#9 ·
Stop it, Michael! lol

I hate being along in a thread...it's too much pressure...and honestly, it's awkward for an OP, who usually would want some unanimity of opinion.

(BTW, don't mention any of my other threads to OP, right now he thinks I know my stuff...if he finds out about my beagle issues, that would end very quickly!)
 
#12 ·
Well I do plan on DIY. My dad knows more about this stuff than I do (I'm still pretty young hahah) so we're gonna do any and all work ourselves. But yes, I am able to shut down and start back up while the car is rolling, no need for pulling over. I'll make sure to recheck the battery. The first time I checked, it felt alright. But aside from that I'll make sure to get the cooling system fixed, then work on the pulleys.

Quick question also, one of my angel eyes just half went out and there appears to be moisture in the light itself (Problems on top of problems,) would that be affected by my leak? I'm assuming I'll have to rewire everything in there or possibly replace the whole light itself?
 
#20 ·
Yes, but not immediately. You'll lose the fuel pump, so you'll only be able to go about 1/2 mile before sputtering to a stop.

OP: This definitely sounds like a connection issue. Or just get your battery tested. You say you're getting 14v while the car is on, so looks like the alternator is fine.
 
#16 ·
Mine just did this the other day randomly as well. I was coming off the interstate to a stop light and noticed my oil pressure light on while I was coasting down in neutral. I looked and my rpms were dead and all my warning lights were on. I just pushed in the clutch and put it in third while I was rolling and let out the clutch and it started back up with no problems. This is like the third time in three years it's done it. I think based on your description yours did the same thing because you mention the power steering going dead too. I had no idea the engine was off, I suspect my icv or vanos because the rpms jump when it's cold out on a cold start. You didn't say if you had an auto or manual. Might be worth looking into.
Green

Sent from my Galaxy Nexus using Bimmer App
 
#17 ·
I have a manual and mine's a bit different than what you're describing. Mine keeps the engine on, coasting while in gear. Then all of my warning lights come on, after that I turn the key off and on (while rolling) and then it starts back up again. But it's done it about 3 times in the past few days so it's definetly not something I should ignore.
 
#18 ·
The reason why I asked was because I was having this issue but it was a jolt off and right back on with no turning of keys or anything. I would go around a turn, hit a bump, etc and I would have this complete loss of power but right back on. After checking everything I realized that somehow the bolt on the battery tie down had come loose and the tie down plate would touch the positive terminal. Sounds like yours is more involved then some simple fix. GL
 
#19 ·
I wonder if you're just stalling because of a dirty icv/tb or something. I used to stall, but it was almost always when dropping into neutral to brake quickly while the rpms were up there a little bit. If rolling, I bet you could just pop the clutch and keep going. If it happened just after a shift, that might be something to look at too.
 
#21 ·
Yeah at this point I'm not to worried about the battery. I'll try going to Costco and replacing the battery there and seeing if it does anything but it is a relatively new battery. It was put on in November I believe. But you still never know.

And dmax, thanks for all of the info, I'll make sure to give the icv a good clean and see if that does anything.

Btw, does anyone here have any idea on how to get moisture out of my headlamp? My angel eye has moisture in it... Half of the angel eye went out and its flickering on the whole lamp as well (only one lamp) does anyone know a fix to the moisture problem? After that issue is fixed I'll go through all of the connections for it and see if any are bad. Worst comes to worst I'll rewire it.
 
#25 ·
OP Bump.

Well great, I get down there to bleed the cooling system and not only do I have a coolant leak, but an oil leak as well. Looking into that. Luckily we know a guy who is the service manager at a BMW dealer so he'll have a diagnosis done for free. I'm hoping that it's just the oil filter housing gasket or o ring. But the location of the oil (e.g. everywhere) says otherwise. Oh well, one step at a time. I have the car up and I'm taking care of the radiator and belts at the same time (while checking the pulleys as dmax suggested) so hopefully all goes well so I'll be able to drive it to the dealer and have it checked out. I'll try to see what I can get done in my autoshop class as well. Assuming I can get the car safely running by Saturday.
 
#26 ·
Find your coolant leak...you don't want to drive it until you know where it's from and can assess just how risky even a short drive is. There are some places a leak is really bad and should stop you from driving.

Others, like a seeping o-ring, you can usually get a slow, predictable leak from and still drive...if you replace your lost coolant, of course.

Sounds like you've got good support around you...nice!
 
#27 ·
I already know the source of the leak, it's from a crack in the plastic piece on the radiator right by the expansion tank. So I'm in the process of replacing the radiator and hopefully that's the only source of a leak (after taking it apart, everything else seems okay.) But I'll keep this thread updated with the status.
 
#28 ·
Alright status update. So I got the radiator in last night only to have a loose hose (make sure you check your buddies work) pop out and spill coolant everywhere. So I get under there today (I REALLY hate coolant by this point) and take care of that. While I was in there yesterday I checked the pulleys and replaced the belts. The pulleys seemed all good so I got the new belts on and it hasn't had the same problem since which is nice. So hopefully that solved my issue, however I can't be too sure so I'll post back here if it does happen again. All that needs to be done now (assuming all is well with my shutoff issue) is that oil leak and I'll have the thing running great. It feels good to drive my E46 again. Once again thanks for all the support in this thread. This forum has been very good to me.
 
#29 · (Edited)
I don't think it'll solve your issues. I had a similar problem. I'm running 2 amps in my car, one is a 500 rms and other 450. I'm also good with electronics but I could not understand why my system seemed to be losing power as I was slowing to a stop. Mine wouldn't stall out but it also seemed like it was caused by my system when I'm really bumping. Also my head unit would turn off then turn back on when I turned it up too high. I thought it was my voltage regulator or alternator going bad.

It turns out I think it was my alternator having been covered in a mix of what might be my power steering fluid and maybe oil from an oil leak coming from oil filter housing gasket. I've fixed the gasket, which kind of sucked. I haven't done the replacing of my PS hoses, which show obvious signs of crusting and oil leak like caking. also there's PS fluid on the reservoir all the time. Yesterday, I decided to spray my alternator down with engine foam cleaner and brake cleaner, and followed it up by rinsing with electrical quick dry spray cleaner. Making sure I allowed it to dry properly, I took my car on a test drive, since I also did an oil change. Crossing my fingers, I cranked up my system. It felt like my system was hitting harder and I also felt more available power accessible by my engine. It felt strong. I had my system bumping the highest volume it had ever gone up to ever since issue began. before, i couldn't turn it up pass 13-16 without head unit shutting off and coming back on frequently. I had my volume up pass 25 and no signs of power loss on deceleration. If you look at your alternator and see black oil leak like stains caked all over the copper wires on the alternator, clean it up. see if that helps.
 
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