Car keeps going dead: 5 mechanics later, still unresolved

[Becky88]

Trevor555 said:

I'm sure this would be one of the first things a mechanic would have checked.

I would have thought so too, but after having 6 different mechanics diagnose different issues, I'm willing to suggest anything.

[Megaflow]

Becky88 said:

Megaflow said:

Ok, now that really is weird. You say it ticks over, but won’t start. I think what you mean is it turns overs, but won’t start. Tick over is another saying for idling.

Apologies, let me clarify.

The very first time I had an issue (about 2 years ago), it turned over. Since then, it doesn't turn over at all. When it dies, it's completely dead. No lights, noises, turning over, etc.

EDIT: Also, thank you for educating me on terminology. I didn't even know there was a difference between 'turn over' and 'tick over'. I was just using 'tick over' as a synonym. Thanks for the explanation

Edited by Becky88 on Thursday 27th May 19:55

Ah, ok. That rules out fuel issues. But equally the fact it works fine with no intervention a day or so later also rules out starter, alternator and battery. Very strange.



ETA: I get the logic of the engine earth strap people have mentioned, but that would only effect engine functions, not the lights etc as well.

Edited by Megaflow on Thursday 27th May 20:39

[Huntsman]

I'd be looking carefully at the earth leads, the ignition switch and the key itself.

I guess there is a chip in the key and an aerial around the ignition key barrel to energise the chip and read it.

[imagineifyeswill]

What kind of mechanics are you using, if the battery is dead and you fit a new one but the car still doesnt start it certainly wouldnt suggest a faulty alternator. If the alternator was faulty the vehicle would start ok until such time as the new battery went flat.

This to me sounds like a bad earth or faulty immobiliser not recognising the key.

I had a customer come to me with a Transit similar problem, he took it to Ford, they diagnosed variuos things eventually fitting a new starter motor. Few days later vehicle wouldnt start again, took to another garage who diagnosed and replaced battery, again worked for a few days until that battery went flat, thats when he arrived at me. took me approximately half an hour to diagnose the chassis to engine earth was faulty. the very earth wire bolted to the starter mounting, replaced by ford two weeks before. Cleaned the earth connection at engine end no more problems.

[whatmoretyres]

All of these suggestions... get rid!

A car you can’t rely on to even start isn’t worth the space on the drive. I know easier said than done but I think you’ve spent too much already. How old is it?

[wilksy61]

A few years back I had a similar issue with my Westfield, one day it would start the next it wouldn't, I spent an age taking off the battery, taking of the starter motor and anything else that was a battery draining possibility. I bought an expensive geared starter motor, changed the alternator and each time I did something it would then start and run, only to be deflated when the next day it was the same. This car was my Sprint and Hillclimb car so it had a fair amount of mods etc.

Eventually more by luck than anything else I discovered the real fault, it was the live cable attachment point to the battery, basically every time I moved the cable it would "reconnect" to the battery and start then over a short time the cable would relax and there would not be sufficient cable to handle any current and nothing would work.

Cost to actually fix the issue - non I had a spare battery to cable mount - actual cost - hundreds and hundreds of pounds but at least I got a new starter and alternator.

[M4cruiser]

OP, it's time to give up on this, go buy a used Yaris, you'll never look back.

[rustednut]

This reminds me of a similar problem on a Mondeo I had a few years ago. Too long ago to remember the full details.

Appeared to be battery/alternator fault as in sudden no power/non start.

Took ages to actually identify but turned out to be a fusebox fault and the local ford dealer admitted to me it was a known (but not ever so common) issue.

The way it was confirmed, after a battery change and alternator change, and starter motor remove and test, was to just disconnect the battery, wait 10 seconds, reconnect and it would start, but before disconnecting it would appear that the battery was dead.

May not be the same fault, but worth talking to ford dealer

[Penelope Stopit]

Becky88 said:

Fast forward to today. I’ve taken my car into Ford, explained all of the above to them and said it’s the computer module as 2 independent mechanics had diagnosed it.

Call from Ford earlier, computer module is fine. Says he doesn’t know what the issue is, other than it’s a “massive short” causing the car to die. Told me he’d call me back to confirm issue within an hour. That was at 3, it’s now 16:45 so I’m guessing he can’t find the issue.

Nobody will be able to find the cause of the fault while the car is working correctly

Anyone can throw some new earth cables and other parts at it but they won't know if they've fixed the problem until you have been using the car for a good length of time

The best solution is to leave the car with a reputable auto electrician, asking them to use your car daily until it fails on them and they can then test for what the cause is

Any other method is nothing but guessing

[buggalugs]

I'll be a bad earth or 12v connection on a big fat wire somewhere. When it's dead someone needs to go over it with a multimeter and see what the deal is. Prime contenders would be around the fusible link since a few people diagnosed it, around the battery, starter and alternator since they've been messed with too often temporarily fixing it.

[Penelope Stopit]

Becky88 said:

Call from Ford earlier

Says he doesn’t know what the issue is, other than it’s a “massive short” causing the car to die

The above is nothing but a guess and a very poor one at that

Massive shorts blow fuses or burn wires

[geordiepingu]

Brights on and all of this might be a clue. Do Fiestas have body control modules? Perhaps ones that integrate with the alarm/immobiliser? I remember my 2008 Mondeo Titanium X doing similarly strange things when the battery went flat in terms of the cabin being entirely dead and things being unresponsive after storing it over a year without a trickle - even low power stuff like the radio, windows etc that you would hope show some flicker of life. Not even a flicker of light on the gauge cluster or interior lights. Didn't quite have headlight faults though. Point being that could be a place to start looking for Earthing faults and shorts, rather than barking up the tree of alternators and batteries.

I also looked after a Boxster 987 S - my then girlfriend's mum's car while she was on holiday - some years ago when the roof leaked and flooded the rear body control module. I remember coming home to the alarm going bonkers and learning a Porsche locks the key in the barrel and had to 'jump' the car through the emergency frunk release to power the car up and get the keys back out of the barrel. Typical fashion of everything being absolutely dead and not even responding to the keyfob. If nothing else, despite my reasonable mechanical and electrical skill (mostly from restoring 90s classics) it was funny that it took me 30 minutes to try and get the keys back out of the ignition barrel. Point being it's amazing what unexpected moisture ingress can do with integrated circuitry.

As other folks have said, a dealer master tech will have Ford's support on this who can hopefully trace such a problem. I agree with Penelope though that it sounds like they may be muttering 'WTF' amongst themselves and unsure where the fault is - time will hopefully reveal the smoking gun. Perhaps 'massive' was a failure in communicating the quantifier of 'massive short' actually being 'massive confusion probably caused by small non-obvious electrical gremlin that doesn't blow fuses but sends the wrong inputs to integrated circuits making them not do things' :-)

Edited by geordiepingu on Saturday 29th May 05:06

[Becky88]

geordiepingu said:

Brights on and all of this might be a clue. Do Fiestas have body control modules? Perhaps ones that integrate with the alarm/immobiliser?

Yes they do, and the two mechanics I had out prior to taking it to Ford (one of which was an auto electrician) both said it was the body control module at fault. Unsure whether or not it integrates with the immobiliser, but Ford said they didn’t think it was the body control module.

I got my car back and it’s so far starting up, but again this morning when I got into my car I had a problem with the aux not recognising my phone again and becoming “frozen” (the aux screen froze but the rest of the radio worked) so given this was one of the issues that went hand in hand with the starting problem, I fear that the issue hasn’t actually been solved yet again.

Fair play to Ford, they haven’t charged me yet and said to bring it back on Tuesday for a voltage test (and other retesting maybe) so they can establish of the issue is fixed but I’m going to call them later if they’re open and say the issue still seems to be present.

Think I’ve got no choice but to give up on this car...

EDIT: not sure if related but this morning is the first time I’ve used the car with my lights on, and this is also when the radio has got stuck since getting it back. Beginning to think the short or whatever Ford think it is might be directly related to the lights. Thinking back, I think the other times I’ve had problems is when I’ve had my lights on.

Edited by Becky88 on Saturday 29th May 05:04

[geordiepingu]

Becky88 said:

EDIT: not sure if related but this morning is the first time I’ve used the car with my lights on, and this is also when the radio has got stuck since getting it back. Beginning to think the short or whatever Ford think it is might be directly related to the lights. Thinking back, I think the other times I’ve had problems is when I’ve had my lights on.

The radio will interface with it via CANBUS more than likely - it's possible incomplete messages on the CANBUS from interference are crashing the radio. Incomplete messages/interference can translate to wiring faults, bad modules or even moisture. Could be something as 'simple' as voltage from the lights or their associated relays etc making its way onto the CANBUS signal wires and causing the radio to crash - the sort of short that wouldn't blow a fuse but would cause absolute havoc with your electronic systems. I would imagine a competent auto electrician with an oscilloscope would find this and isolate the fault quite quickly with a reasonable degree of confidence.

CANBUS being the digital communications bus that all electronic modules will talk to each other on if you weren't aware. It is not dissimilar in concept to how computer data cables like USB etc pass high and low voltage signals in a certain pattern to transmit data between devices.

Don't blame you for your part-ex thoughts - it doesn't sound like a forever car so it could be worse.

Hope I'm not telling you how to suck eggs!

[sliks]

Previous faults youve had may or may not be linked to current issue.

[quote] I’ll pop into a shop and come out to it dead.
[/quote]

When this happens. Is this after a very brief first drive of the day or after a good run? What has been done to get the vehicle running again after it dies at the shops?

[Chris32345]

Megaflow said:

Ok, now that really is weird. You say it ticks over, but won’t start. I think what you mean is it turns overs, but won’t start. Tick over is another saying for idling.

The fact it is dead one day, and works another day, and turns over even when it won’t start tells me it is not the starter, alternator or battery.

Modern cars have an intertidal switch the turns off the fuel pump in the event of an accident. I wonder if yours is dodgy or the fuel pump maybe, but a fuel pump is unlikely to get better once it has failed.

A failed fuel pump wouldn't result in a dead car just stop it running
It should still turn over fine

[Belle427]

Does seem to point to a poor connection somewhere either battery or ground cable.
Very hard to guess at.

[Becky88]

sliks said:

“I’ll pop into a shop and come out to it dead.”

When this happens. Is this after a very brief first drive of the day or after a good run? What has been done to get the vehicle running again after it dies at the shops?

Varies. Sometimes after a long drive it’ll die immediately as soon as I turn the engine off, whereas other times it’ll be used multiple times throughout the day or week with no issue and then just randomly won’t start for no reason. There doesn’t seem to be any consistency to the issue at at all. It’s such a random yet annoyingly persistent problem. It happens enough that I can’t risk using my car for risk of breaking down, yet intermittently enough that it could be fine for weeks to the point I’ll develop a false sense of security thinking the issue has resolved itself.

To get it running again, again it varies. Sometimes it requires jump starting, sometimes it just revives itself with no assistance. But again, the length of time it’s dead for is completely variable. Sometimes dead for literally 10 minutes, sometimes dead for weeks or months. Sometimes it’ll work for 1 quick trip and die, other times it’ll work for weeks or months and then die.

For example, I took the car to Asda on my way home from work, which is 20 minutes up the motorway. Worked fine getting to work in the morning, and fine getting me to Asda on the way home after sitting in a car park for 8 hours. No issues at all. Was in Asda for probably 10-15 minutes at max, came out and DEAD. No lights, key fob won’t work, won’t turn over. This was before I had jump cables and was the first time it had broken down away from my home (I’d been lucky previously in that it was always in the morning when I tried to leave for work that it wouldn’t start) so I was going to call a break down vehicle. By the time I’d managed to find the phone number for the free breakdown assistance I had with my insurance, the car came back to life. The only reason I even knew it was working again was because I’d got out the car to get a better 4G signal and when I went to get back in again, I pressed the unlock button on my key fob out of pure habit and the unlock lights flashed as they should to let me know it was unlocked. I tried the engine out of pure chance as I hadn’t yet called the breakdown line and boom, started up first time like it was brand new.

Edited by Becky88 on Sunday 30th May 09:40

[ARHarh]

Stuff worth looking at that I have come across over many years of running old cars.

Loose or bad earth as suggested. This would be my first choice
loose or bad connection to battery or starter.
Do you have a lot of keys hanging from the ignition switch (if it even has one?) I have seen this break the switch before now.

Things to try

When it doesn't start, try putting in second gear handbrake off and rock the car backwards and forwards to see if it frees the starter, or hit starter with big lumpy thing. Also try wiggling the battery cables then see if it will start.

Set off ten minuets earlier to work, as if you are not running late it will surely start every time

[Becky88]

ARHarh said:

Do you have a lot of keys hanging from the ignition switch (if it even has one?) I have seen this break the switch before now.

Interesting, yes I do actually. I keep my keys bulky with multiple key rings because I’m bizarrely paranoid of dropping them down a grid, despite this having never happened to me. Never realised this could cause an issue though. What would cause the ignition to break from this, the weight?

ARHarh said:

Set off ten minuets earlier to work, as if you are not running late it will surely start every time