/ leaving a car idle for several months

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Kimono - on 10 Feb 2013
Am going to be off travelling for 6 or 7 months and will be leaving my car unused whilst i am gone.

Do the car-wise of UKC think it is best to:
a) disconnect the battery and just leave it
b) have someone start up the engine every couple of weeks and let it run for a bit
or c) something else??

Anything else i should be considering??
Radioactiveman - on 10 Feb 2013
In reply to kieran b:

Leave it with the wheels chocked to allow the handbrake to be disengaged. Saves the brakes seizing on.

Not if you live on a hill/slope though
kathrync - on 10 Feb 2013
In reply to kieran b:

If you go for option b, make sure whoever is starting it actually drives it somewhere, otherwise you will drain the battery turning the starter motor and never re-charge it.

I usually go for b, but then it doesn't usually get left for more than six weeks at a time...last time I was away for longer than that I sold the car first!
Kimono - on 10 Feb 2013
In reply to Radioactiveman:
its an automatic so i guess no need for chocking...thanks anyway
Kimono - on 10 Feb 2013
In reply to kathrync:
> (In reply to kieran b)
>
> If you go for option b, make sure whoever is starting it actually drives it somewhere, otherwise you will drain the battery turning the starter motor and never re-charge it.
>
> I usually go for b, but then it doesn't usually get left for more than six weeks at a time...last time I was away for longer than that I sold the car first!

not an option for them to drive it anyway (it would be in storage and they just start and run).
But is it true that it would drain the battery? Wouldnt having the engine running keep the battery charged??

Its all a bit of a hassle buying and selling cars here so prefer to keep hold of it...i can also use it to store my stuff in whilst im gone!

In reply to kieran b:

We are away a lot, the longest so far being about 4.5 months. After an earlier dead battery (away 12 weeks) the AA guy suggested just disconnecting the battery - that is what I always do now. No issues over the past couple of years.


Chris
kathrync - on 10 Feb 2013
In reply to kieran b:

You have to run the engine for quite a while if you aren't moving to re-charge. If you can't drive it, it's probably better not to start it.

My other half works off-shore. Before we were seeing each other, he would leave the car with a friend who would start it every couple of days but not move it and it was invariably flat when he got back.

Now I have it when he's away and often I don't use it at all...it's always been fine. When I do use it, I actually drive it somewhere and that seems to work too.
Run_Ross_Run - on 10 Feb 2013
In reply to kieran b:

I had mine started every month while we were away (7 months) and everything was fine when we started using it again.

Read somewhere that you shouldn't rev it once its started as it builds moisture in the exhaust and causes premature rusting.
Kimono - on 10 Feb 2013
In reply to Darren09:
ok, nice tip!
redsonja - on 10 Feb 2013
In reply to kieran b: i was away 2 months last year. my friend started my car every couple of weeks and just left it running for a while. it was fine. i didnt know that you should actually drive them rather than just start them
IainFP on 10 Feb 2013
In reply to kathrync: The battery is charges via the alternator which is driven by the engine. Whether the car is moving or not! The output should be constant regardless of rpm, only requiring sufficient time to rebuild the charge used in starting.
Requiring "movement"???Has yours got a dynamo on the wheel?
Kimono - on 10 Feb 2013
In reply to IainFP:
> (In reply to kathrync) The battery is charges via the alternator which is driven by the engine. Whether the car is moving or not! The output should be constant regardless of rpm, only requiring sufficient time to rebuild the charge used in starting.
> Requiring "movement"???Has yours got a dynamo on the wheel?

Exactly what i was thinking....about how long does it need to run to recoup that start-energy Iain?

IainFP on 10 Feb 2013
In reply to kieran b: A quick bit of googling would suggest that if the "systems" are all in good nick then 45seconds to 2mins.

Would recommend running it for sufficient time to let the cat etc heat up sufficiently/engine reach normal operating temp. 5 mins or so I would think.
Kimono - on 10 Feb 2013
In reply to IainFP:
ok gracias!
Ben Sharp - on 10 Feb 2013
In reply to kieran b: Wouldn't worry too much about the battery, will probably be fine just left or you could use a battery charger but if it doesn't survive the storage it's not a huge cost to get a new one.

Spray some lubricant in your locks, make sure your tyre pressures are up or jack it up to save your tyres, if it's due an oil and filter change do it before you leave it, pull the windscreen wiper blades up to stop them sticking, put fresh coolant in if it's too diluted, put a rag in the air intake thing and exhaust to stop any animals from getting in. Petrol quality is good here and your not leaving it long enough to degrade, fill the tank up to avoid condensation build up and add stabilizer if you want but probably not necessary. Might be worth putting a note on the steering wheel of everything you've done in case you cop it while your away, would save someone starting it with rags in the exhaust!

Also don't forget to claim back your vehicle tax if it's off road and you might be able to get a reduction on your insurance.
Jim C - on 10 Feb 2013
In reply to Ben Sharp:
> (In reply to kieran b) Wouldn't worry too much about the battery, will probably be fine just left or you could use a battery charger but if it doesn't survive the storage it's not a huge cost to get a new one.
>
> or jack it up to save your tyres,

Smiles at thought of someone starting it up to drive off and the wheels just spinning.....

Some fancier cars may loose radio passwords/codes or even have immobiliser problems if you let the battery go flat. Worth checking if this is a risk and if so recording these before they go.



summo on 10 Feb 2013
In reply to IainFP:
> (In reply to kathrync) The battery is charges via the alternator which is driven by the engine. Whether the car is moving or not! The output should be constant regardless of rpm, only requiring sufficient time to rebuild the charge used in starting.
> Requiring "movement"???Has yours got a dynamo on the wheel?

not strictly true, car starter batteries are designed to give a high ampage in a short space of time, then charge up slowly when moving. As opposed to leisure or deep cycle batteries, small current - over long period of time.

Alternators at idle speed don't push out many amps, plus all the anxillary electrics on a modern car at idle speed eat into this a bit too. So most alternators have an optimum speed, perhaps 1500-2000rpm, so unless you start it and put a brick on the accelerator it won't charge up what it lost with just a short period of time on idle.
summo on 10 Feb 2013
In reply to Ben Sharp: I think you've got it covered. If I was doing a long spell away, I would often leave a footpump and jump leads in the boot. Nothing more annoying than being unprepared when you're tired on return.
Cheese Monkey - on 10 Feb 2013
In reply to kieran b: a]

I left my motorbike with half a tank of petrol for 15 months. Bump started it as the battery was flat, went for a ride to charge it, done. It does not need to be run every week.
Kimono - on 10 Feb 2013
In reply to Ben Sharp:
> (In reply to kieran b) Wouldn't worry too much about the battery, will probably be fine just left or you could use a battery charger but if it doesn't survive the storage it's not a huge cost to get a new one.
>
> Spray some lubricant in your locks, make sure your tyre pressures are up or jack it up to save your tyres, if it's due an oil and filter change do it before you leave it, pull the windscreen wiper blades up to stop them sticking, put fresh coolant in if it's too diluted, put a rag in the air intake thing and exhaust to stop any animals from getting in. Petrol quality is good here and your not leaving it long enough to degrade, fill the tank up to avoid condensation build up and add stabilizer if you want but probably not necessary. Might be worth putting a note on the steering wheel of everything you've done in case you cop it while your away, would save someone starting it with rags in the exhaust!
>
> Also don't forget to claim back your vehicle tax if it's off road and you might be able to get a reduction on your insurance.

Thanks for that detialed reply Ben. Worth noting however, that im not actually in the UK and petrol quality is not good here...so is it better to leave it full or empty?

will try not to 'cop it'...but you never know :)
rocky57 - on 10 Feb 2013
In reply to kieran b:

For me the ideal situation is to have someone start it every couple of weeks and drive for half an hour, or 20 miles. It turns everything over and lubes everything that needs to be lubed. More importantly, it moves the tyres, parking it and not driving it means you end up with the weight of the car always in the same position on the tyres. If you leave the car stationary for a long time the tyres will retain the bulge that appears at the bottom of the tyre. This in turn will then cause vibration when you drive afterwards. Trust me I know. Irrespective of if you start it up or not, the thing to do is either ensure it moves (driven around), or it jacked up and left on axle stands or bricks. Even having to buy one tyre is expensive, up to four is an unnecessary outlay.
Theho - on 10 Feb 2013
I once left my mazda 626 for a few months. The person i asked to start it once a week forgot and i came back to a completely flat battery ie even the clock was dead!
It never really recovered as the computer codes were wiped and despite re-setting the system, the idle speed controller struggled to idle the car from that point on, causing it to idle at 3-4000rpm+ or to cut out at traffic lights depending on how much I had manually shortened the accelerator cable by under the bonnet!. It produce some hilarious traffic light stops until I got bored of having to left foot brake, restart it or dive under the bonnet every time i stopped.
I have seen some solar panels you can put on your windscreen and plug into your lighter to keep the battery topped up but don't know if they're any good.
I would hire it out to someone......??
Ben Sharp - on 10 Feb 2013
In reply to kieran b: I'd be lying if I said I knew what I was talking about but you really aren't leaving it that long so I doubt it would be a major problem. If you leave it empty then condensation may build up in the tank, if you leave it full then the petrol may degrade. What's the humidity where you are? Might be worth leaving the windows very slightly open if it's hot and moist. Leaving the tank low/empty means you can fill it up when you start it and dilute any gungy petrol. I kind of doubt that 6 months is enough for petrol to get to that state but I don't really know. Maybe look into the stabilizer thing, I've never used any.
kathrync - on 10 Feb 2013
In reply to IainFP:
> (In reply to kathrync) The battery is charges via the alternator which is driven by the engine. Whether the car is moving or not! The output should be constant regardless of rpm, only requiring sufficient time to rebuild the charge used in starting.
> Requiring "movement"???Has yours got a dynamo on the wheel?

No idea...all I know is that starting it and not running it ran the battery down really fast whereas starting it and driving it didn't...
fraserbarrett - on 10 Feb 2013
In reply to Theho: That was nothing to do with the ECU idle govenor, the default setting and learning statergy will not be affected by a dead battery (or else it'd be an issue evry time you took off the battery cables). You most probably had a clogged fuel filter........
fraserbarrett - on 11 Feb 2013
In reply to kieran b: As has already been mentioned your biggest concerns are fuel quality and tire deformation. Chock it up and fill the tank (fuel is hydroscopic and absorbs moisture, and condensation will rust your tank. A full tank stops condensation and minimises the area for water absorption (fill it to the brim).
As for the battery, disconnect it. This will maximise the time it will retain charge. Lead acid batteries really suffer from electrode erosion when they are full discharged and are never as good afterward. leaving it connected will allow it to slowly discharge.
When I was a student I was given a ford Capri for free, on the condition I picked it up. It had been sat since 1992 and this was in 2001. We arrived with a trailer, but almost for a joke put the battery from our tow car in and tried to start it..... it took a long crank but it started! We drove it onto the trailer. It had been left on bricks and with a full tank of fuel. Needless to say it I syphoned off the fuel and put new tires on but otherwise it was not too bad a runner!
richparry - on 11 Feb 2013
In reply to kieran b:

I've left cars parked up for months at a time. Ideally it's best if someone can drive the car regularly for you.

Before you park it up, give it a good clean, and be sure to clean the underside and the wheel arches. Get all the muck, salt or whatever else off. Clean all the brake dust off the wheels.

The car will get damp inside, especially over the winter. If I couldn't get someone to drive my car regularly, I'd get them to run a dehumidifier to help prevent condensation build up. You could try those condensation traps people use in motor homes or caravans as well. These will need emptying and topping up with new crystals regularly though. Mould can/will grow on the fabric quite nicely thanks to condensation.

If the battery is good it might be ok to leave it on the car. There's no guarantee, so it's up to you. If you do disconnect it, your alarm won't work, which may be a problem. Depends on where you park it I suppose.

I've just put a car back on the road which had stood for 5 months. I had to recharge the battery, sort the brake calipers which had a couple of stuck pistons (although they were sticking before it was parked up), and sort out an idle control problem. Luckily my brother is a whizz with this sort of thing, but without the right diagnostic gear you could run into problems.


summo on 11 Feb 2013
In reply to richparry:> sort the brake calipers which had a couple of stuck pistons (although they were sticking before it was parked up),

With older cars with rear brake shoes, not pads, a long screwdrvier and a big hammer often helped free them, with a persuasive tap! But brakes left off I've never had a drama.
Ben Sharp - on 11 Feb 2013
In reply to fraserbarrett:
> (In reply to kieran b) ...condensation will rust your tank.

His tanks probably plastic, but I guess it's not great to have condensation in the tank anyway.
John_Hat - on 11 Feb 2013
In reply to kieran b:

Don't know if its been mentioned but when we had two cars and only ever used one of them the unused one was parked up for weeks at a time, and the battery used to go flat.

Got a solar trickle charger

http://www.sunshinesolar.co.uk/khxc/index.php?app=gbu0&ns=prodshow&ref=SS946&sid=8d0j1pe...

and never had a problem again.
scott titt - on 11 Feb 2013
In reply to kieran b:
What a lot of worriers on UKC.
When I worked in Bavaria our yard was next to the entry point to Germany for Hungarian built Suzuki Swifts (among other cars). The cars were driven off the car transporter train and parked up (with the keys in) and left outside in a Bavarian winter (-20c at worst). Up to a year later they would be driven off to be sold, only a few needed a jump start.
I guess most people don't realize how old their "new" car could be!
MaxWilliam on 11 Feb 2013
In reply to kieran b:

A full tank is a bad idea. Fuel degrades/loses its calorific value over a relatively short period (my experience 6-8wks). Best to leave the tank with minimal fuel, then add a can or two of fresh fuel when you come to put the car back on the road. Many boat owners find their petrol outboards hard to start after winter - usually due to the fuel degrading. Same with lawn mowers.
HB1 - on 11 Feb 2013
In reply to kieran b: had a flat battery in Skye one time. After getting it started RAC said best drive it for, I think, about 10 miles (and he followed us, just in case. Had a flat battery in Settle not long ago. After getting it started RAC followed me to the garage, because I needed petrol, and he wanted to make sure it started again. The car spends most of winter garaged (handbrake OFF - that was an expensive mistake last year!) so we drive out in it once a month - no problems so far this winter
escudoturbo - on 11 Feb 2013
In reply to kieran b: jack the car from the ground and place on axle stands. Take the spark plugs out and put a spoon of mineral oil in each cylinder. Disconnect the battery and fill the tank to the brim with petrol.
MaxWilliam on 11 Feb 2013
In reply to escudoturbo:
> (In reply to kieran b) jack the car from the ground and place on axle stands. Take the spark plugs out and put a spoon of mineral oil in each cylinder. Disconnect the battery and fill the tank to the brim with petrol.

More nonsense! We're not in the 1950's! Park it up with the tank as empty as possible, leave the handbrake off (but wheels chocked) and walk away. Modern cars will tolerate a many months of neglect. The brakes and clutch may stick a little but a start in gear will normally sort this. If the battery dies jumper leads will sort or you buy a new battery.

Ben Sharp - on 13 Feb 2013
In reply to MaxWilliam:
> (In reply to escudoturbo)
> [...]
>
> More nonsense! We're not in the 1950's! Park it up with the tank as empty as possible, leave the handbrake off (but wheels chocked) and walk away. Modern cars will tolerate a many months of neglect. The brakes and clutch may stick a little but a start in gear will normally sort this. If the battery dies jumper leads will sort or you buy a new battery.

I think the same laws of physics still apply in 2013, tyres still suffer from being left with a car weighted on them, metal still rusts and spark plug threads are no different and condensation will still build up in the tank. All these precautions may be a little over kill but they're not necessarily wrong, especially with an old car.
panz - on 13 Feb 2013
In reply to kieran b:
I suggest there be no argument how much of abuse modern car would stand however encouraging it may sound, but to introduce something like better practice, so
-solar trickle charger,
-axle stands,
-tank full to the brim,
-wipers stored,
-cylinders and keyholes oilsprayed,
-brakes and clutch ( if present) disloaded,
-and the best of luck
Bruce Hooker - on 13 Feb 2013
In reply to kieran b:

Instead of chocking the wheels you can just leave it in first gear... remember when you come to start again. In fact it's well worth leaving the handbrake off and in gear whenever it's been raining hard, you've driven in water, especially salty, or after driving on salted roads as some cars suffer from stuck brake drums quite badly. I once had to take the back wheels off and bash the drums with a hammer to free mine off. Boat trailers can have the same problem.

As for the rest, I've left petrol in tanks for long periods without a noticeable problem, as for leaving a full tank at least it avoids getting rust in the tank, although that only happens after several years rather than months. Squirting a bit of oil in the plug holes (on a petrol engine) and turning the engine a few turns to spread oil on the cylinders is standard practice for boat engines, especially outboards but I don't know if it's necessary for a car - can't do any harm though. I also spray all the outside of my boat engine with WD40 before the winter break - about 6 or 7 months - but this again is because of the salty conditions, it protects the wiring and such like.

Jacking the car up to take the weight off the tyres and springs is probably no longer necessary for a light car but for anything heavy it's a good idea.

Disconnecting the battery is worth doing, but if it's a modern car you may need to put a code in and re-tune the radio.
John W - on 13 Feb 2013
In reply to Bruce Hooker:
> (In reply to kieran b)

> leaving a full tank...avoids getting rust in the tank

How many cars these days have a metal tank? Not a rhetorical question, just curious.
Bruce Hooker - on 13 Feb 2013
In reply to John W:

No idea, I haven't dismantled a car for quite a while :-) The last ones i scraped - Austin 1100 and a mini both did. If they are plastic then rust is not a problem, so I suppose one could go for the empty tank scenario.

Frankly though for most cars I don't think anything more than taking the battery lead off and not leaving the hand brake off is required.

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