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I was getting some electrical problems suddenly yesterday (couldnt turn the car over, then a very weak start about 2 minutes later), chalked it up to very short drives between house > store > gas station pulling too much battery and not recharging, but then as I went along my drive the ABS and ASC light came on, then radio cut out (and back on), and finally all systems cut out with the engine still running. I suspect the alternator was going and first failed to properly recharge the battery, then after the car drained the battery while driving I was left with only what the failing alternator was putting out/scraps from the battery to send spark to the engine. I got it towed home and am trying to pick a new alternator.
I'm going to grab a multimeter and check the battery, but I have 2 questions for BFC:
1) Alternators- Ive run a search and seen some conversation about which ones to use, but I'm wondering where people are at with these in 2022. BMW is over $400 after the core (ouch), but FCP has remanufactured Bosch and Valeo units for under $250. Anybody have bad experiences with the Bosch and Valeo units recently? Im really not trying to buy one of the Genuine units.
2) Assuming my battery was completely drained- I need to replace it dont I (ouch again, its 2 months old)?
Car is 97 M3.
Thanks
Member
Reman is fine. As long as it comes with the pulley you can swap from valeo to Bosch and vice versa. Valeo is smaller and lighter and fine unless you have well beyond stock electrical needs.
Member
First thing, fully charge the battery with a real charger. Only then can you make a call on whether you need a replacement.
Like pbonsalb said, reman is fine. In fact, it used to be that remans got better parts than originals, bearings usually, but I'm not completely sure that's the case now. I have used everything from new to 'cheapest I could find' for complete units or parts to rebuild and never had any issues, so far. Just look around for the best price for the Bosch or Valeo. I would probably stay away from the ridiculously priced 'new' and usually Asian units advertised on a site with a South American swampy type name, but the reviews aren't bad so give us a report if you go that route. Check the engine to chassis ground strap under the exhaust manifold, right side.
See ya later,
tony
'98 M3, '92 Dinan3, '05 R1100S BCR, '07 R1200S, Aprilia T
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Your assumptions may be correct but you should really do some basic testing. Immediately put the battery on a charger (3-4hrs) after that start the car, test the voltage it should be around 14.4V, anything below 14V and your alt is bad. Its possible its just the voltage regulator or the brushes are worn out. Bosch regulators are fairly cheap, valeo are more and it would be better to just get another alt. If you do get a reman'd unit it has to have a really good warranty.
Attn. NEWBIES: Use the search feature, 98% has already been discussed.
Click the search button, select "search single content type", select the "e36 sub forum" specifically, try the "search titles" then try the "search entire posts".
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I ordered a Bosch reman, the car is 25 years old and new to me with patchy service records so I'm assuming and confirming that a lot of parts are original. I can afford to just replace the whole thing and don't really feel like taking it apart at this time. Ill check that ground strap, reading about that sent me down a rabbit hole and added an inspection of the trunk wiring harness to my to do list.
What exactly do you mean by recharge the battery; like a wall to battery charging device? I have zero experience with electrical troubleshooting and am trying to catch up.
EDIT: here is the trunk wiring thread if anyone here hasnt seen it yet: https://www.bimmerforums.com/forum/s...WIRING-PROBLEM
Last edited by Charlemango; 08-08-2022 at 05:26 PM.
Member
Your '97 shouldn't have bad trunk wiring, that was more for the older e36's.
Yeah, its bad for a battery to be left in an uncharged state. I have the one below, but any charger meant for car batteries will do:
https://www.amazon.com/Automatic-Bat.../dp/B07Q3VF9DC
- - - Updated - - -
If you wanted to go cheap:
https://www.amazon.com/ABLY-Automoti...dp/B096RV6XWY/
Attn. NEWBIES: Use the search feature, 98% has already been discussed.
Click the search button, select "search single content type", select the "e36 sub forum" specifically, try the "search titles" then try the "search entire posts".
Member
I've read through about 20 pages of the trunk wiring thread, it appears that no car is safe. I have found several 97 M3 sedans in there with the problem, as well as 98 cars. It is possible that it has been well addressed by a PO on my car, but needs to be visually examined regardless.
Member
Since your battery is only 2 months old I would think it has some sort of warranty on it. Call or bring it back to the place you got it from and ask.
You should also get a battery tender!
Member
I've been through about 7 alternators - you absolutely want to stay away from anything that isn't at least Bosch or Valeo reman. The good ones are also far more likely to have the threaded insert in the rear rather than a blank that will require you figuring out how to get a nut on the back (and also finding a longer bolt). Just one of the bonus problems you'll avoid by avoiding the cheap ones.
My original lasted 200k and about 20 years. I went through 6 cheap ones over the course of about 2 years and 30k miles until I had enough and stopped using the "free" replacements and just bought a reman Bosch 140 amp unit.
Since this is my DD, I am at times forced to go to O'Reilly's and such when something decides to die in the middle of a road trip or when I need the car back on the road ASAP - like when the alternator died at 8:00 pm in Waco on the way from Austin to Dallas. To their credit, one of the local Waco O'Reilly's had one, and I was back on the road two hours later. To their discredit, it didn't last a year, and then I had almost monthly trouble for a second year until I gave up and bought a nice 140 amp Bosch. No more trouble.
Re: the battery. All good advice to charge it back up and see how it does (not jumping it and driving it, but really charging it). If it's a good quality battery it'll likely recover. After my battery got trashed from all of the above, I went and bought one from the dealer. My original (to me) battery was purchased from the dealer, and lasted over 8 years of daily use in the cold (Salt Lake winters) and hot (Dallas summers). Similar to the alternator, I went through 3 batteries before getting tired of the constant uncertainty and "free" exchanges (and even AFTER getting the Bosch alternator, which I thought would sort it finally) and bought a factory battery. Again, problems over.
-Josh: 1998 S54 E36 M3/4/6 with most of the easy stuff and most of the hard stuff. At least twice. 271k miles. 1994 E32 740il with nothing but some MPars. 93k miles.
Member
I went straight for the Bosch 80a, I've heard so many stress stories about bad alternator replacements. Ill be curious to see what brand the current one is when I pull it off. I found a Shogun essay about alternators that so precisely describes what happened to me that I'm feeling pretty confident that it is the alternator. Not to keen on chasing electrical problems.
I pulled back the sheathing on the trunk wire and found that 2 wires did in fact have their coating severed, so there is another data point. I will wrap those 2 in tape and keep an eye on it going forward.
Did you drive your car when the roads are salted? Im planning on parking mine in the winter, but curious how you kept yours from rotting out.
Member
We were only in Salt Lake a year with the car before I got a job in Dallas. But my car grew up in New York before my uncle bought it and shipped it to Idaho, so it spent 12 years in snowy salty winters. The body doesn't have any rust to speak of, including the underside, but I did replace the rear subframe because it had a lot of surface rust. The front subframe doesn't have any rust, though. And at this point I've been through all the mechanical stuff that was rusty / ruined (like the rear suspension ball joints). I don't know - but I don't think Idaho uses salt much, it's more sand than salt like they use in other places.Originally Posted by Charlemango
-Josh: 1998 S54 E36 M3/4/6 with most of the easy stuff and most of the hard stuff. At least twice. 271k miles. 1994 E32 740il with nothing but some MPars. 93k miles.
Member
question for you about the rear subframe job.
I'd like to get this done in the next year or so but have a conundrum on hand. I want to do all the removal and reassembly in my 1 car garage, and take to a shop to get bushings pressed out and in. I also want to get RTAB reinforcements welded in at that time. Am I going to be screwed trying to find a reputable welder to do this in a 1 car garage with shitty ventilation? I don't think I'm willing to get a craigslist cowboy to do it. Once the subframe is out and the chassis is prepped, there's no way to get the car moved to a shop in that state, right? So with my current space my options are:
1. get whoever is willing to do the job to weld in the plates (maybe no one will do it, or have to pay a premium)
2. skip the plates- its sounds like this is a bad idea. The car is all street for now, some aggressive driving, but it would be nice to at least auto-x in a couple years.
3. pay a reputable shop to do the whole job. any clues as to what that would cost?
4. leave it, let the back end get looser, hope I get a 2 car garage or move somewhere I'm willing to do the whole job outside.
Member
Welding in a 1 car garage is fine but if you can’t find a mobile welder (tell him what voltage you have access to and plug type), maybe do the RTAB reinforcements later. Do your subframe first. Prep the RTAB holes for welding by cleaning the area to bare metal. Drive the car to a welder, Jack it up, unbolt the RTAs so the welder can do his thing. Bolt them back up. Go home, drop them again. Paint/rust proof. Reinstall them. Align.
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