Just been to my '90 C2 to give it it's weekly blast to find that the engine wouldn't turn and the lights on the dash were dimmer than usual. I am presuming it's a battery related problem. My mechanic will come over tomorrow to have a look. If it is flat battery are their any repercussions and will the car need some tuning to get back to it's old self again.

Unfortunatly my car is in semi storage and I only get to drive it about once a week. It's in an air conditioned lot and I don't lock it (to save the battery) as it's under the eyes of 24 hour security under a car cover. The last few time I've noticed it being a little slow in turning over so have taken it out for a good hours run to charge it, but this seems not to be enough obviously.

Is there anything I should suggest my mechanic disconnect to stop this leakage in the future.

Thanks
Tony
'90 C2

 

Dear Tony,
Before you start paying for amechanic to check your C2 out, I highly recommend you check your battery out. Remove it, have it fully charged and then capacity tested. Storage as you describe does horrible things to batteries. In fact having the alarm system off makes things worse. How old is your battery?
Current drains normally wipe out the battery in 2 or 3 days, not a week. Now your battery is still working but with reduced capacity, unable to crank the engine. This is a typical symptom of the storage and run cycle.
As for the rest of the 964. When you flatten a battery or disconnect it, you will reset the DME. This means you need to carry out a spirited 15 minute drive, using the full range of rpms and gears as possible.
There is plenty on this subject in previous forum pages and the archives.
Ciao,
Adrian
911C4

 

Thanks Adrian,

I'm not sure how old my battery is, as I've had the car for only 17 months and haven't changed it. The car doesn't get much of a run which frustrates me as much as anything. I will have the battery checked as you suggest and hopefully won't need to replace it.

 

Let me know how it turns out. 17 months of only one short drive a week is not good for the battery. It may be quite happy with a full recharge, capacity check under heavy load and then a recharge. Batteries like to work hard.
Ciao,
Adrian
911C4

 

The saga continues...

My battery needed replacing, the mechanic's said it was no good, he couldn't speak english so gather this from some hand signs. So out came the Porsche branded one and and in went a Varta, that didn't look particularly new but did the job immediatly. I took the car for a spirited run as Adrian suggested (the fun part!) straight after the swop and all seemed ok. Today again just 5 days after the swop, the same problem, the engine wouldn't crank.

I called the workshop manager who's english is better and he said it might be the alternator. This could be at fault and is not charging the battery. Does anyone know whether this a problem they have had, or should I suggest to him it could be another problem.
They will collect the car tomorrow to find out and I would like to be armed with a few questions or options for them to look at.

Thanks
Tony

 

I suggest you check the lights in both the engine and luggage compartments. Make sure the are off when the lids are closed.

Eddie, 1990 c4 Melbourne Australia

 

Adrian,

You said it will be worse if alarm is off (battery drains out faster)? Why is that?

I need to sit my car for five weeks or so and I've been debating whether to disconnect it or not, or leave the alarm on or off?

You said current drains out battery in 2 or 3 days, you meant 2 or 3 weeks, right?

Would it be the best to disconnect and lock the doors with the keys?

My battery is brand new Optima.

 

You might consider a battery maintainer, sold by Porsche dealers and elsewhere. It plugs into the cigarette lighter socket and maintains the battery at the proper charge level without overcharging it. I've been using it for awhile now and the battery always has a full head of steam. I believe it helps save the alternator too, because the alternator no longer has to recharge the battery during your occasional drives.

 

I just noticed that you say your car is in a lot. I guess you might not have an outlet handy to use a battery maintainer.

 

I don't have an outlet, I think best choise is to take the battery out & lock the doors with the key (there is security in the garage so that should be ok).

Then when I get back, connect the battery and do some 'spirited' driving (like I wouldn't else!)