Starting the 8 after being parked for a week

Craig

These cars consume huge amounts from the batteries even when parked,i had a similar problem to you so i got some larger capacity batteries fitted & all is fine since

Same here - If i leave the car for a week or more I put it on a trickle charger. THere is a huge drain on the batteries when left parked up and if your batteries are slightly weak they will not last long!

Ben

would it benefit the owner to put in Optima yellow top deep cycle batteries?

Batteries

Craig;

Four to seven days to wear the battery out means either:
1) Weak batteries
2) Low capacity batteries
3) or both 1 and 2

When in sleep mode, the batteries lose 1% of their power per day. Most 8's with powerful batteries can last nearly three weeks without turning over. However, as the advice being given, if you're not going to use your car for an extended period of time, use a trickle charger.

The battery issue is not confined to the 8 Series. Because of the intense use of electronics, all luxury cars have this challenge (e.g E38 750, E65 745/760, Mercedes S600/CL600, etc.). That's why there's been discussion of increasing the voltage in the cars from 24v to 48v for some time.

Here are some resources for you in the battery discussion:

E31FAQ - Battery FAQ

E31FAQ - Optima Batteries FAQ

Good luck!

How old are your batteries ? You should be able to leave it for a month easily with no problems.

I've been having the same problem, however I've never used a trickle charger. How do you hook up? One per battery? On one battery? or under the hood at the jump start points? Is there a risk of hydrogen ( or other gasses) building up in my garage?

Hi all,

My batteries are completely dead now. Usually I could leave the car parked for two weeks with no trouble a all. Now I left the car for a couple of days and the batteries went dead. I plan on jumpstarting the car to get get some new ones. Will I be expecting any trouble when I jump start it? I mean, will it go in limb-mode or anything else?

Peter

Zitat von peter1980

Will I be expecting any trouble when I jump start it? I mean, will it go in limb-mode or anything else?

Peter

Had to do the same before i changed them (with much much higher
starting power). And there's not any major problem, only engine is idling very poor but only for a couple of minutes (ECU needs some time for setting).

Adam

Zitat von peter1980

Hi all,

My batteries are completely dead now. Usually I could leave the car parked for two weeks with no trouble a all. Now I left the car for a couple of days and the batteries went dead. I plan on jumpstarting the car to get get some new ones. Will I be expecting any trouble when I jump start it? I mean, will it go in limb-mode or anything else?

Peter

If jump starting these I recommend connecting the jump leads and waiting 10 minutes (to charge your batts a little). This helps get a successfull start.

I had some shit arsed batteries in and used to carry two sets of jump leads around. Using two sets to a single car helped. Using two cars to jump me always worked straight away. Usually one to the boot batteries and another to the bonnet hook points.

Another tip - dont use the alarm if your batteries are low. Double lock the door and use the code lock on the OBC instead. Voltage measurements showed me that if you had the headlights, and the blower fan on the batteries would not be charged much even on the motorway! Leave radio/climate control/seat/lights off to get your batteries back to charged. Even fast (High amp) charging can take 4 hrs so always best to charge fully before installing, unless going on a roadtrip!

I work with batteries and they loose a lot of efficiency when they become cold - hence your battery woes are generally in autumn/winter. If you have one dead one, that will kill the other quickly, it would be best to disconnect it entirely untill a replacement is bought.

You can get trickle chargers that go into your cigarrette lighter socket, all thats needed is a connection to the 12v loop.

And it is 12V on these cars the batteries are in parallel.

Thanks for the advise. I managed to jump start the car using ONE 44 Ah battery from a car of a colleague. The startermotor barely turned over, but I managed to get the car going fairly easy. Good thing the engine doesn't need much cheering on to get going.

May I use this thread to illustrate another possible problem with parking up for over a week?

Put my 8 into the bodyshop to get a couple of parking dings and a cracked spoiler fixed. 8 days later went to collect it, and on start up got a really horrible metallic ticking sound which seemed to emanate from the R. hand Cylinder head. Anyway, it was so loud and worrying that I approached the Bodyshop owner and virtually accused his people for revving the bollocks out of my engine from cold. He got the guy who started it up that morning ( minus 2C) The guy swore that he never revved it, simply idled out of the bay. I sat for a good 10 min. outside the shop and it was still ticking away. I then decided to drive it and see if putting it under torque would make any difference. Oops. within 5 minutes the engine sounded perfectly normal, and now 3 days later starting up at conditions (Aberdeen) below zero, no problem.

So, what is this? Are the tappets hydraulic? Would the car sitting for over a week in cold weather result in oil drainage?

A scary scenario when you he3ar a previously perfect engine ticking away like an amplified Grandfather clock and you're scared to rev it.

Anybody else experienced this?

Sometimes, but only for a few moments.

I would say that all of the oil had drained from the cylinder head & given the extreme weather possibly magnifyed it somewhat.

I think it only goes to show the importance of a good quality oil.

Steve, thanks, but I guess I'm a bit of a cold start paranoia merchant.
Having lived for 16 years in Nigeria and listening every morning to our drivers revving the nuts off our cars (just warming up Boss !!) I really do get a bit anal about this. Anyway, I'd just changed the oil (Mobil 1) with a flush last month, so hearing that bloody noise I guess I thought the worst.

Apparently no damage done. But, where would I be without the support of all you guys?? Thanks.

In the BMW 8 handbook it says for engine protection on cold days you are best driving off straight away.

I guess the oil pump works better once you are going and circulates the sludgy oil to the top of the engine better.

Perhaps check the oil level?

I have the same experience. When I park the car for a few days I can also hear the enginbe tick for a couple of seconds. Immediately after that it's fine. There was this one time that the ticking did not go away after a few seconds, but that was because there wasn't enough oil in the engine. I suspect that Steve is right: the oil needs to be pumped around to get to the head.

Peter

ps. I second you paranoia

I have the same problem but only for a split second. Oil pressure is bang on as the light goes out in the same split second.Had changed to a thicker oil and i reckon that doesn't help the cause.
Les