Battery changed....breather hose and engine power question

[RequiemMetal]

Hi All,

Hopefully someone can help, give advice.

Battery completely dead in my 997.2. I think it was on the way out anyway, 7 year old Porsche battery in it, and had been sitting on a neighbour's drive for 2 months while a skip was on mine.

Battery wouldn't take a charge (through the cigarettle lighter socket), so using a jump pack connected to the post in the footwell I got the bonnet open and took out the battery. Put it on a proper charger and it wouldn't take any kind of charge at all...completely dead.

New battery needed therefore, and reading some posts on here, and around, I went for the Bosch Silver S5 110 battery which I installed all ok. I've since, though had the following issues:

- When I turned the key, got a load of error messages, which i was expecting based on posts on here as the power had been disconnected.

- The car was quite hard to start, and had to use a bit of gas to get it going. I also had to keep my foot on the gas for a few second after starting, otherwise it would die. Never had to do that before, but once I'd done that it settled and seemed okay.

- All of the error messages cleared within a few minutes of driving, other than one saying "engine power reduced" which has stayed. The car seems limited now at a certain number of revs.

The car was running perfectly prior to the battery change, so I can't believe there is a problem with the engine, so assume the starting and engine power issues are related to the battery swap. I read on here someone mentioning about losing "fuel trims" when you change the battery and therefore it is lumpy for a while after. Is that the issue do you think? I've only driven about 30 miles in it so far...do I need to drive more for ECU to 'relearn' and this error be cleared? Or is this going to have to be an OPC matter? Or something else going on? Do you also need to do something to tell the car you've changed the battery (read that somewhere too)?

My other question was relating to the battery breather hose. There's nowhere to put this on the Bosch S5? Reading posts on here, albeit ones a few years old, from people who have used a Bosch Silver S5 battery, they talk about plugging the hose in, and bunging the outlet on the other side of the battery. On my Bosch I do have what look like outlets on either side, that are the right size for the hose, but on inspection both are actually completely sealed with nothing to remove? I've put the hose there anyway, as somewhere to put it.

Anyone know anything about this? I phoned Eurocarparts, where I bought the battery from, and the 2 people I spoke to had never heard of a battery breather hose and didn't really know what I was talking about?

Any advice much appreciated.

Thanks.
SW

 

[JonnieD]

It sounds to me like you need to put a code reader on the car and see what comes up.

I've not heard of a car going into limp mode purely from a dead / replaced battery. I know about the codes they throw temporarily as mine did it too.

As for the battery, you don't need a vent pipe on it. They do have 2 bungs (top left and right) which are in place when the battery is transported, but once in the car must be removed.

 

[m1kegibson]

As per previous reply, I have never had an engine management issue after swapping/disconnecting battery on my 997.2 - the usual PSM error until driven a mile or so etc. but never an engine management error. If you have access to a code reader that would be the first obvious step.

As for the battery, if it says it is sealed, no breather/vent required. However, I don't think the S5 is sealed. I would suggest unplugging one of the stoppers (the one at the same end as the breather pipe) and plug the breather in there. They put one at each end to allow for either orientation of breather pipe. As lead acid batteries give off hydrogen and oxygen gas when near/at full charge it is better to connect a breather (than not) so any gasses are dispersed. The likelihood of an issue if the breather is not connected is low (there's not that much gas given off) but better to connect it than not if there is one. You should always remove one of the bungs so any gas does not become pressurised inside the battery.

 

[deMort]

I would hazard a guess that the poor running issue is more to do with it standing for 2 months ..

You will need to get a fault code readout as already mentioned .. it may well be the high pressure fuel pump is or was messing around .

The throttle position would also have been lost being that flat .. the car will relearn it , or you can do it with a tester but releaning it is not instant .

Fueling adaptions in theory should not be lost with a flat battery .

 

[RequiemMetal]

I would hazard a guess that the poor running issue is more to do with it standing for 2 months ..

You will need to get a fault code readout as already mentioned .. it may well be the high pressure fuel pump is or was messing around .

The throttle position would also have been lost being that flat .. the car will relearn it , or you can do it with a tester but releaning it is not instant .

Fueling adaptions in theory should not be lost with a flat battery .

Thanks for that. Will prob have to take it to the OPC then. Hopefully sorting the pump isn't too extortionate to got done!

Thanks for your help.

 

[Magic919]

The Bosch S5 batteries I've bought have all had vent holes. The car has a pipe that attaches.