So, carclueless mate went off for 3 or 4 months travelling, and in the last minute panic before leaving, forgot to disconnect his battery or leave his keys with someone to run the engine for a bit every few weeks while he was away.
Surprise, surprise, came back at the weekend, battery's a metaphorical pancake.
So, I brought jump leads around yesterday, connected them up using some other friends' 206 and his car started fine. [pretend I know something about cars]I suggested he take it out for a spin and get some high revs, etc etc[/pretend I know something about cars]. But as it's SORNed and no MOT or insurance, he didn't want to chance it. We ran it on high revs for a few minutes and then left it. Everything seemed to be working. A couple of hours later when we came back from getting some lunch, he tried starting it again but it wouldn't go. We had to rush off and I said I'd pop round this morning and jump it again so he could get to work.
Tried again this morning, but this time with a diesel van...once we connected up the batteries, his car went beep beep beep, which stopped as soon as he put the key in the ignition, but wouldn't start. No dashboard lights...nothing. Anyway, just as well it's a nice day today...he's on his bike.
I always thought you could jump a petrol car with a diesel but not the other way round. Was it something to do with trying with a diesel engine?
His car's a Y-reg Audi A3, with alarm and immobiliser. I'm thinking the car was somehow immobilised which didn't reset...but then again the alarm bleeping did stop when he put the key in the ignition.
Any suggestions (apart from a new battery, which he'll be getting anyway)?
new battery should sort it. The battery has prob gone into a state of deep discharge which it wont recover from ever, so will never hold its charge...
jump starting from a diesel/petrol doesn't really make much odds. a diesel car usually has a bigger battery as it does take more amps to get a diesel going (so bigger battery = more starts with a full recharge between & more life as you put less 'stress' on the battery each start), but you'll get it going the once by bump starting no probs.
using higher revs wont make any difference to the amount of charge going into the battery.
your issue this morning was almost certainly immobiliser related. They are funny old things when battery voltage drops below a certain amount.
sounds like the immobiliser is doing its job...
Yeah, find out how to reset the immobiliser first, otherwise you've no chance as your fuel pump isn't working until you do!
oh, and trying to jump start a truly dead battery wont work - all the current from the good battery/car goes straight into a black hole of the dead battery. If you try to bump start from a good car, there's not enough juice to satisfy the black hole battery [b]and[/b] the engine starting.
What he said ^^^^. New battery and a good read of the owners manual regarding the imobiliser/dead battery situation should see you right.
oh and again... did you check the van was 12v and not 24v?
using higher revs wont make any difference to the amount of charge going into the battery.
Yeah, I had a sneaking suspicion I was bullshitting here but you know what it's like, you gotta sound like you know what you're talking about 🙂
oh and again... did you check the van was 12v and not 24v?
I said my mate was clueless, not me! But no I didn't 😳 It's a 58 plate Berlingo 1.6 HDi...would that be 24v?
EDIT: My main reason for questioning my undoubted skills in jump-starting were based mainly around the fact that it started from a 206 battery yesterday.
Had the same prob here trying to start a pick-up that had been standing for a few months. Couldn't start it using jump leads from a fairly large SUV with its engine runing. Would barely turn the motor over (and the leads got very hot - so I agree with the black hole theory!)
Cured the problem by just charging the battery over night. Good as new afterwards.
🙂
the berlingo is almost certinaly 12v 🙂
This morning's thing was probably coincidence - you just happened to drop the voltage below the immobilser's pre-set thing. Trying to charge the battery the other day may have destroyed it even more meaning it really couldn't hold it's charge. Immobilisers are great until you legitimately need to get the car bump started, when they can be a nightmare!!!
Ok, cool. Thanks cp.
I checked the Berlingo, yes, it's 12v. I think it was my car instinct that told me not to bother checking 😯
