My thoughts Tim, rather than opposing opinion as this video will help someone bricking a module which is unrecoverable. I'm using 35 years on the spanners with some electronic experience (to be completely transparent 20 years of that, was corporate IT and cars as a hobby) those connectors under the bonnet are for convenience (as stated by BMW) battery location which helps with the neutral front/rear balance can be a time consuming activity to access (model dependant). The problem is some of these cheaper jump starters is they have burst voltages way above 20 volts (non BMW alternators may have this issue, I can't say) which is enough to corrupt modules whereas most BMW alternators top out at 15 volts which is just within the safety threshold. To summarise briefly and reduce any possibility of module corruption (jumping BMW to BMW which I do for coding sometimes) I'd connect jump leads with the jump car engine off, then try to start the car with the flat battery. The extra 100 amps or so you'll get with the alternator running (assuming you have good jump leads capable of carrying 200amps minimum) isn't going to make a huge difference and most batteries sit between 12.5 to 13 volts which is well below the voltage required to corrupt module memory. Just my opinion only, pinch of salt and all that, keep up the good work! :D [edit never killed a module ever, done a few hundred at least]
@TimmsBMWRepairsandInformation3 жыл бұрын
Thanks, these are the sort of replies that keep me going!
@bargla3 жыл бұрын
Sorry I just came upon this and I have to say [quote] "connect jump leads with the jump car engine off" [quote off] this is the foolest thing to do when jump starting cars. Always have the donor car running before connecting jump leads! The alternator has a voltage regulator unit that will do just fine with any differences in current, but the whole system must be running altogether with donor battery charging. If you connect dead battery with good battery on your car than you are asking for disaster. The difference in potentials between the two batteries can do a real damage to any electronics connected to your battery. I would not do that.
@olifs808326 күн бұрын
@@TimmsBMWRepairsandInformation wow nice info Sir. I just bought BMW E34. I wasn't driving it for 2 months and I have no idea how good battery is. I was about to jump start it just in case if battery is flat. Im im happy i found this video. My question is what to do with battery if I'm not using car for 5-6months? (winter period) It''s safe to disconnect for winter? and is battery charging and connection back is safer? Tthank you.
@bobfrankish9723 жыл бұрын
Yes, well said again Timm, another informative video. Just for the sake of informing a lot of your fans commenting, I have several old cars, including the E31 that I try to keep going and batteries are a pain, as you have so perfectly explained on previous videos. I have, for a few years now, two main tools in my arsenal. One is a top quality "intelligent" battery charger (not too expensive really), and a new spare battery that I keep topped up fully charged. If there is no real alternative to jump starting the dead car, such as where it is parked, then jumping from a good battery rather than another car is much safer. Also switch the headlights on before connecting the jump leads, leave them on until you have disconnected the leads, this gives an extra load to absorb any spikes. Keep the vids coming!
@TimmsBMWRepairsandInformation3 жыл бұрын
Thanks Bob, and good to hear from you!
@olifs808326 күн бұрын
Why not just replace empty battery with full? I'm newbie here. And how you jumpstart car battery? Do you put terminals under hood + and ground for example shock absorber screw)? or empty battery under rear seat to full battery. Nice tip with lights on. Thank you. I will defunetley buy intelligent chartger ans one spare battery. Better safe than sorry. Sorry for those dumb questions😂 i never payed this big attention to these details owning other cars.
@purpletrance98743 жыл бұрын
Wow! I've been lucky so far with my E64 then! I've jumped started mine once and jump started another from it once. I won't be doing that again after your advice Timm. Thanks 👍
@TimmsBMWRepairsandInformation3 жыл бұрын
Always my pleasure!
@Studiosatoshi3 жыл бұрын
Your like tiff needel and James may in one. Thanks for learning me something today .
@TimmsBMWRepairsandInformation3 жыл бұрын
I'll take that!
@theylive82563 жыл бұрын
I jumped started once my e39 from my battery another car, gladly nothing happened. Thanks for sharing this precious info!
@louiebousalim40443 жыл бұрын
I blew my DME in my E64 after Jump starting it. I wish I knew this info before I jumped it. Thanks Timm.
@TimmsBMWRepairsandInformation3 жыл бұрын
Sorry to hear that Louie - and thank you for reinforcing the message in this video!
@brandyisaacks89133 ай бұрын
Hello! Just discovered your channel. I live in the US (California) and have a 1993 850Ci that I love, 3rd owner, 135K miles, had it since 2007 and, as my mechanic says, I will be buried in it - not due to accident but because I will never let it go. I knew that jumping was a bad idea, but since mine is currently dead due to being out of town and not driving it and so happy I saw your video. I will invest in 2 new batteries to be safe. An aside, I watched your vid of getting your car back after accident and you mentioned the headliner sagging. I just got mine done at my local BMW specialist (Coast Motor Werk) and it looks amazing - they did an ultrasuede that matches my gray interior perfectly and apparently will "never" sag. They did an amazing job. I also had the bushings replaced since apparently my engine was resting on my exhaust system. Very different drive after, and I'm not sure I like it since I was not used to a bouncy ride. Mine is silver OG color that is super faded. I am considering Techno Violet (individual color) but love the Maura metallic that you have. Thank you for the videos and the detailed information.
@TimmsBMWRepairsandInformation3 ай бұрын
Always my pleasure!
@123hoffie3 жыл бұрын
What about using the newer lithium or super capacitor jumper packs ? Maybe you could do some testing for us plebs😉
@123hoffie3 жыл бұрын
@@MrFryfish Well, why not can you tell me??
@sportshatch3 жыл бұрын
BMW's are jump started in BMW workshops all over the world every day. In 40 years working on BMW's never once had an issue. With the 1 in 10 rule , I should have had about 200 problems. There is a problem with the maths somewhere .
@craigj24833 жыл бұрын
Never had a problem jump starting my bmw, in fact never heard of anyone ever having problems after jump starting 1. Even bmw state that is what the points under the bonnet are for. Got a feeling people will be doing the most basic mistake and nit connecting red first
@TimmsBMWRepairsandInformation3 жыл бұрын
Thanks for your reply, yes, there is little chance of damage - but the risk is still there and I have been involved with many cases where damage has been done.
@malingeorgiev2962 Жыл бұрын
I think that engineers in BMW know very well what is inductions and the damage that can cause. All electronic modules are designed to stand such voltage picks that can appear when jump start the car. One more thing, when replace the battery I may have same problem connecting the terminals. Is this mean that I mustn't replace the battery? If you afraid from voltage spikes follow the advice from Bob Frankish turn on lights. Resistance is enough to smut spikes. The only problem with jump start is to put wrong polarity. This definitely will damage something.
@andrewthompsonuk13 жыл бұрын
I think the root cause of jump-starting problems (aside from reverse connection) actually comes from the fact the dead car's battery has sulphated of effectively has a high internal resistance. This means that when the car finally starts and the jump leads are disconnected there is not enough resistance in the battery to buffer the output of the alternator which can surge sky high. I good rule of thumb is if the battery can start the car then its probably safe to run the car. Therefore if the car needs to be jump-started then the battery is probably not good enough to safely run the car. One may think the battery will charge up quickly, this is not true on a battery that's been sitting for a long time. It may only take a few amps of current even at 50 volts so there is effectively nothing to clamp down the alternator voltage.
@TimmsBMWRepairsandInformation3 жыл бұрын
Hello Andrew, yes, after producing the video I realized that I had forgotten to mention the battery impedance - which increases the more Suplphated it is - and the state of charge which does exactly the same. As you say, the battery forms an effective load for both inductive spikes and lack of alternator regulation - Thanks!
@simontist3 жыл бұрын
Jump leads with surge protection are available which can manage the inductive effects. Better to avoid jump starting altogether, but there is a technical solution for this problem.
@TimmsBMWRepairsandInformation3 жыл бұрын
Thanks, yes good advice!
@simontist3 жыл бұрын
@@MrFryfish I've got about half an electrical engineering degree, we did cover inductance and all the basic differential equations. Not that I have much intuitive feel for quantities, are you saying jump leads don't cause inductive spikes? Thinking about it, I suppose the starter running and stopping is probably the biggest sudden current change, that happens every time the starter is operated and isn't happening when the jump leads are disconnected.. Even if there aren't inductive voltage spikes, there's still a load-rejection voltage spike when disconnecting jump leads, though that'd affect the car with the full battery, not the one with the flat battery... Maybe best practice should be to turn off the running car before disconnecting jump leads, to prevent load rejection voltage spikes..
@simontist3 жыл бұрын
@@MrFryfish what happens when you disconnect a DC circuit.. the current changes suddenly, causing a voltage spike.
@andrewthompsonuk13 жыл бұрын
Interesting discussion. Older electronic components (ICs) can easily latch-up. When this happens they get very hot and will eventually destroy themselves or their power supply. A transient voltage or spark can do this.
@TimmsBMWRepairsandInformation3 жыл бұрын
Thanks Andrew!
@bluedunn3743 жыл бұрын
'I'm a little bit weerrrr, a little bit weeeeeey, a little bit dodgy!'
@rhar10443 жыл бұрын
Jumped my 99’ e36 M3 a couple times, WITH NO PROBLEMS, at the battery terminal, before I finally replaced the dead battery.
@TimmsBMWRepairsandInformation3 жыл бұрын
Thanks for the info - my video does explain that you are unlikely to damage the electronics - but sometimes you do!
@seanpaul30508 ай бұрын
Just keep a small lithium jump pack in the boot. Check the charge level a few times during the year. In the winter whenever the temp drops to 0, I will hook up a trickle charger to my car battery for a day to keep it fully topped up. Those trickle chargers only put out about 1.5 amps max. So will not harm anything.
@superstrongchedder3 жыл бұрын
Great information! I will definitely not be jumping my E39 after watching this. But what about a jump/starter pack? The sort the connect to the cars battery/jump points and then gets switched on? Do they create the same high voltage spike when there switched on aft connecting to the car? We use them alot at work on modern BMW/Mini Thanks
@TheNickfisch3 жыл бұрын
Those things are perfectly fine, because they got a secure mechanism built in to prevent Voltage spikes. I’ve used them multiple times on my E39 in the past and everything went perfectly fine. But I would suggest to use them directly on the battery in the trunk, rather than using the plugs in the engine bay.
@somerdutrieux46193 жыл бұрын
Damn. I keep a pair of jumper in the trunk. Not the cheap crap with the sheet metal pliers, the real deal that pinch grown man style, made of plain thick metal. And I've jumped a few cars in desperate need of juice here and there. Now that I know, thanks to you Timm, that it can pop a random module of my e39, I'll keep them for my old Civic. She hopefully doesn't mind a few spikes of volts. Or perhaps it could damage the alternator' regulator ?
@TimmsBMWRepairsandInformation3 жыл бұрын
Bung them in the boot of the Civic - they'll be fine there!
@dougquaid47453 жыл бұрын
Hi Tim you know how many thousands of pounds you have saved people? God bless you! I enjoy watching all your videos thanks again.
@gretashapiro4118 Жыл бұрын
My 2008 750li battery does not last long sitting. We drive about once or twice a month. And I need to charge it overnight before. If I try to Crank it over after about a week, it's so weak .I used to charge it from the back directly, then I watched a video saying it will fry the electrical/computer system. Now I charge and " jumpstart " from the front
@TimmsBMWRepairsandInformation Жыл бұрын
You can charge from the batter+ve terminal and the chassis, you cannot use the batter-ve terminal. You will not have any damage, but the ECU does not know the state of charge. Time for a new battery!
@jsmaccready4 ай бұрын
Do modern intelligent jump start systems such as the NOCO Boost models avoid the issues raised in this video?
@TimmsBMWRepairsandInformation3 ай бұрын
It is the early electronics in these cars that causes the problem
@unixnerd233 жыл бұрын
I'm an electronics engineer and I agree with this advice. I'd add that many jump leads are poor quality and can make a fairly ineffective connection. When you consider how much current is needed to run a starter motor and you look at the way many cheap leads connect it's amazing they work at all! If you're having trouble be sure to turn off lights, stereo, fan, etc. and try again with the minimum electrical load. I've seen it make the difference on a low battery.
@TimmsBMWRepairsandInformation3 жыл бұрын
Thanks from another electronics engineer!
@beautgrainger147 Жыл бұрын
I can certainly say that thin leads weren't enough to start my 190D when an alternator brush had worn down too far and it wasn't at home.. had to have it connected about 5 minutes before it would start (the diesel can drive without a battery but won't start that way).
@puopolvj23 жыл бұрын
Thats some solid intel. Well done.
@TimmsBMWRepairsandInformation3 жыл бұрын
Thanks Vincent!
@kevinansell93419 ай бұрын
Why do BMW fit jump points under the Bonnet if its not advisable to utilise them ??
@TimmsBMWRepairsandInformation9 ай бұрын
They are not Jump points, they are charging posts!
@kevinansell93419 ай бұрын
Umm, Despite watching quite a few BMW Videos where they all use the under bonnet remote posts to jump the car your still firmly in the minority who say not to, Confused now, Additionally I messaged NOCO USA and asked if their Range where safe to use in this manner and they stated it was not a problem as long as they were used correctly. The other thing that has me puzzled is the posts are way over rated for just a charger connection, Looking more up to the task of a Jump cable of Booster Clamp. So we agree to disagree on this one
@antster73 жыл бұрын
How about charging your existing batteries? I noticed you have a charging lead only on the left battery?
@TimmsBMWRepairsandInformation3 жыл бұрын
Yes, I have a CTek MSX 5.0 fitted to both cars to keep the battery in good condition. The E31 batteries are in parallel and you only need to connect to one of them as they are treated as one BIG battery!
@tedcollins46843 жыл бұрын
As long as you don't connect the cables backwards and key is out or switch is off, it's ok.
@TimmsBMWRepairsandInformation3 жыл бұрын
....usually it is - sometimes it isn't!
@unixnerd233 жыл бұрын
Many BMWs have a sleep mode for 16 minutes after you remove the key. So modules are still getting power.
@Transportador333 жыл бұрын
As always, thanks for the education Tim.
@TimmsBMWRepairsandInformation3 жыл бұрын
My pleasure!
@trpple.92712 жыл бұрын
I own a E32 740IL 7 series, and my battery out, thanks to you're video I will not jump it, but charge it I will do, but I can only locate the positive under the hood and not the negative. Is there a specific bolt or knot that will suffice for ground coverage? Like one of the bolt/knots that are located right were the shock absorbent is
@TimmsBMWRepairsandInformation2 жыл бұрын
Yes, that's the one, the larger nut on the suspension shock tower.
@alioral13583 жыл бұрын
Timm thank you, also the problem is most Bmw owner is just do sth then invest is it right or not. Some of them dont know black, red polar. I saw important mistakes outside. Some Bmw services even dont know how to charge battery. In Turkey is it normal to service destroy your car easily.... 2 days before I cleaned all grounds, checked alternator and its diods, cleaned sockets and got new Varta battery to make all system brand new. I have also battery charger with 3 A to make my battery minimum 12.50 V. )
@TimmsBMWRepairsandInformation3 жыл бұрын
Good to hear from you Ali!
@alvintobe55663 жыл бұрын
Hay Timm this is Alvin, your number 1 fan. QUESTION: When I replace my crankcase vent valve, do I need to replace or clean my breather hoses?
@TimmsBMWRepairsandInformation3 жыл бұрын
Hello Alvin, good to hear from you - yes, clear the hoses as much as possible!
Is there any difference when you connect and disconnect a battery?
@bstratford22 жыл бұрын
Thanks Timm.
@TimmsBMWRepairsandInformation2 жыл бұрын
Very welcome Brian!
@noahburnham72402 жыл бұрын
Then why is there jump leads if your not allowed to do it? The factory has them for a reason
@TimmsBMWRepairsandInformation2 жыл бұрын
I can only give my own experience, and that is of our old BMW's failing when jump-started or giving assistance to other cars.
@frankd963 Жыл бұрын
Does this still hold true for the more recent models, say the 2018 X3 M40i G01 B58 engine?
@TimmsBMWRepairsandInformation Жыл бұрын
No, it's only true for 1980's - 2000's models
@cidercecil3 жыл бұрын
Thank you Tim, valuable information ;)
@TimmsBMWRepairsandInformation3 жыл бұрын
Always my pleasure!
@spencerhulme12033 жыл бұрын
Thanks for the very informative video - cheers -
@TimmsBMWRepairsandInformation3 жыл бұрын
Glad it was helpful!
@ussamatayub5794 Жыл бұрын
Does the same apply to an E39 530D ? some context. i jump started a friends car and the next day my battery was completely dead. i did jump start it a few times after but no matter how long i left the engine started i couldnt get the battery to start my engine from cold. side note- my boot/ trunk latch developed a fault around the same time (broken spring) so the light inside the boot wouldnt turn off so i figured thats what had drained my battery over some time. However, i changed the battery for a brand new one as well as getting a new latch fitted and all was fine until a couple weeks later. i did not drive it for between 24-48 hrs and the battery was flat again . dont understamd why its happened can anyone give me any suggestions?
@TimmsBMWRepairsandInformation Жыл бұрын
Yes, same applies to the complete E39 range - you need to measure the current drain - all explained here: kzbin.info/www/bejne/bnKuipyFfsShr8k
@alvintobe55663 жыл бұрын
Hi Timm this is Alvin, your # 1 fan. Thank you for is video. Very informative, I just want to keep my 645ci safe. Say safe. 😀
@TimmsBMWRepairsandInformation3 жыл бұрын
Thanks Alvin, good to hear from you!
@OilBaron1003 жыл бұрын
My jumper leads have inbuilt surge protection; are they safe to use?
@TimmsBMWRepairsandInformation3 жыл бұрын
Possibly, but do you want to take that risk?
@OilBaron1003 жыл бұрын
@@TimmsBMWRepairsandInformation my E46 318i had a bad battery. I had to give it quite a few jump starts before I finally bit the bullet and replace the battery. A couple of months later, I had to replace the transmission module as well as the ABS module. I suspect the previously bad battery, or the numerous jump starts may have contributed to the module failures.
@cyberfile3813 жыл бұрын
Good Advice
@TimmsBMWRepairsandInformation3 жыл бұрын
Glad you think so!
@ttattx3 жыл бұрын
Well... my 07 X5 just got a jump as it was the only way to get it off the highway
@TimmsBMWRepairsandInformation3 жыл бұрын
Yes Keith, sometimes you just have to pull the trigger when there is no alternative.
@spaceexplorer66363 жыл бұрын
My question is my classic E38 only gets driven a few times a month and the way I store it is disconnect the negative terminal at the battery, when I’m ready to take it out for a spin I just reconnect the negative terminal ( there’s always a little spark when touching the terminal with cable), then I have power and it starts. Am I taken a risk by doing this? Thanks in advance.
@TimmsBMWRepairsandInformation3 жыл бұрын
No, that's fine, I've never heard of any damage being caused by disconnecting the vehicle battery
@peterolley7159 Жыл бұрын
I have a BMW I’m going to buy a 6 series next year but all this can’t jump start them because of the electronics just goes to show how crap these cars actually are! BMWs look great so do mercs but we buy with our eyes and worry about power instead of thinking logically and thinking about the mpg and reliability and quality of the car
@TimmsBMWRepairsandInformation Жыл бұрын
You are fine with a 650i - you can jump-start them all day. It was the early DME's in the E31, E32 uo to the E39 that was the problem
@shamidmathura95923 жыл бұрын
Hello Timm question for you love your info, I’m at a dead end with my car I change the battery and rebuild starter it started 4 times and went beck to making a clicking sound and will not start it’s a E 38, please let know what I’m missing or what’s wrong thank I need your HELP THANK YOU
@TimmsBMWRepairsandInformation3 жыл бұрын
I would guess that the refurbished starter failed - it has been known!
@shamidmathura95923 жыл бұрын
@@TimmsBMWRepairsandInformation thank you Timm I did run a direct from the battles to the solenoid wires. It had no movement so I’m in the process of replacing the starter, I’ll let you know, thank you🙏🏻
@HennyManTactics2 жыл бұрын
So how do I get my car started
@TimmsBMWRepairsandInformation2 жыл бұрын
Charge or replace the battery, that's the safest way....
@olifs808326 күн бұрын
@@TimmsBMWRepairsandInformation This is scary. Old bmw e34. it is safe to remove battery charge and put i back or charge while battery is in car connected. I don't want to mess up any modules. Thank you
@wileybalthrop92062 жыл бұрын
2012 BMW 750 i Xdrive
@TimmsBMWRepairsandInformation2 жыл бұрын
You're fine jump-starting one of those!
@alexander-matthiaskonig25522 жыл бұрын
It is normal for n62 4.4 series 6 to have when i drive hard 103 grades water temperature? Thanks
@TimmsBMWRepairsandInformation2 жыл бұрын
Yes, that's fine - anywhere between 90C and 110C
@mohamedal-rashid3993 жыл бұрын
I’m keeping battery maintainer connected on my E31 terminals, is it OK??
@TimmsBMWRepairsandInformation3 жыл бұрын
Yes, that's fine.
@olifs808326 күн бұрын
how long period you keep that battery maintainer like that?
@m2kev7893 жыл бұрын
Oh no Timm! I jumped my 840 yesterday - it ran though and I drove it about 24miles without issue- do you think I’ve got away with it this time? Wont do it again though! Thanks for the tip👍😀
@TimmsBMWRepairsandInformation3 жыл бұрын
Don't do it again Kev! Yes, usually OK, sometimes not!
@Connor-tp5to3 жыл бұрын
I should really replace my batteries...
@TimmsBMWRepairsandInformation3 жыл бұрын
You should Conner!
@3ricky133 жыл бұрын
Hole in hood?
@Shahbeb23 жыл бұрын
Pop up headlights...
@TimmsBMWRepairsandInformation3 жыл бұрын
Lets the light out!
@alioral13583 жыл бұрын
Richy Rich Bimmer 8er )
@nunyabidniz28683 жыл бұрын
What a useless rust bucket. Thanks for the warning, just another confirmation that only idiots waste their $ on them!
@denmasters.findyourinnerde94153 жыл бұрын
Hi Tim, kind of related but then again maybe not..... my e64 boot has stopped working and I can’t open it at all. It did this a couple of months ago and then over night started working again..... do you think this could be a fuse? The latch? The battery? Any help you could give would be great before I send it in to the mother ship to change me mega money.... Chris.
@TimmsBMWRepairsandInformation3 жыл бұрын
Unlikely to be a fuse, much more likely to be the actuator - they do go wrong and would be a cause of intermittent failure.
@denmasters.findyourinnerde94153 жыл бұрын
@@TimmsBMWRepairsandInformation Hi Timm thanks for the reply - very kind of you. Just to let you know (you've probably got better things to do), but boot all fixed. I bought a new latch from BMW near me and fitted it - of course it wasn't that - but took to a garage just behind my house and they had it an hour and called and had fixed it - it's not ideal as the boot only opens with the key but the roof still comes down - and it only cost me £20 - could have taken it to BMW and had it completely fixed but could have added another couple of zero's on the end and seeing as I'll keep it until it dies (which will hopefully be a few years yet) I'm happy with that. Keep up the great videos!