Hot start issue, PLEASE HELP!

[puddock]

Hi, hope someone can help me with this. It happened a few times last year when the car had been running for a while and then stopped it wouldn't start up again. Turn the key, it clicks and nothing happens! I totally forgot about it after a while as I got the car late on in the summer and it hasn't been an issue since then but in the past few weeks it has started happening again except now it doesn't matter if the car has been sitting for hours after use, if it has been sitting in the sun it just won't start. I've been stuck in the work car park twice already this week! It starts again after a while and opening yr engine bay seems to help but nothing feels hot under the hood so I don't knoe where the problem lies. Been moving the car all morning to stay in the shade but think my boss might get a bit pee'd off with me running in and out all day every time there's a bit of sun! Hope someone can help!
Katie

[citronut]

i would check/clean/tighten the feed terminal to the starter solenoid,
this is the small gauge wire with the lucar/spade terminal on the end

regards malcolm

[bx petrol auto saloon]

Dear Puddock,
One thing you may want to try, is running a very good quality ( thick ) jump lead from the bellhousing to the negative terminal on your battery. This may work if you are having a bad earth problems to the starter motor.
Vince,

[Tinkley]

Check the earth strap from the negative battery terminal to the engine case/transmission housing. It pays periodically to remove the M8 13mm flat bolt and abrade the casing and possibly the terminal clip. On the aluminium transmission cases you can get corrosion over time and it goes unnoticed. There is also another copper braid strap which earths nearby. As mentioned above the starter terminals can be cleaned and remounted. BEWARE before you attack the starter motor connections disconnect the battery first - you don't want a nasty shock!
Not sure which model your BX is, if petrol strip and clean the carb especially the autochoke passageways
then check float weight and needle valve assembly.

[puddock]

Thanks everyone, all sounds a bit technical for me to attempt myself! Hopefully Rohan will have a better idea than me! I've been meaning to change the battery terminals anyway as they keep coming loose and jumping off the battery, bumpy Scottish roads certainly aren't helping that problem, hopefully between the 2 of us we'll manage to go through the checklist. Either that or il be chasing the shaded spots in the carpark all summer

[mat_fenwick]

It won't be fuel related if it's not even turning over...I think Malcolm has suggested the most likely cause - if you have a multimeter you can check teh voltage at this terminal whilst still connected to the starter. If significantly less than battery voltage there's your clue. Problems with the thick leads are more likely to give slow cranking rather than none.

[Way2go]

The problem could be the battery itself. If a cell has gone high resistance, the battery will seemingly charge, It will even support the headlights being on but when you turn the ignition, "click" or nothing. Your battery may be in between starting to go and totally knackered.

A good test is to try and start the car with the headlights on with someone watching them or reflected so you can see them. If the headlights cut out or totally dim the fault is likely to be a bad cell or the battery clamps are not making a good connection.

[Dollywobbler]

If the battery terminals are loose, that really won't help. The Mk1 BX that Citsandcycles has went through a very annoying phase of going dead when trying to start. Sometimes the third or fourth attempt would result in success.

[BX Bandit]

It'll be the solenoid sticking on the starter motor, usually worse in hot weather. It is worth checking the points listed above but typically, this problem is the solenoid and it's inside the gubbins of the solenoid (that's the small cylinder on the top/side of the actual starter motor) so you can't do much with it except replace the starter motor or take it apart and try to fix it.

Hopefully, if yours hasn't gone too far, you can try what I do and that is to repeatedly try to start the car in quick succession, as quickly as you can turn the key, eventually the solenoid makes contact and the starter will turn. If its diesel, make sure you wait for the pre heat light to extinguish.

[puddock]

Yeah,its just a bit weird that it only happens when its hot and tightening the battery terminals doesn't seem to help. I don't think its the battery as I have had a few batteries since last year when it started happening due to the problem with the alternator which has now been fixed. Il get Rohan to check the wires etc when he comes home...he's currently off hunting Nessie!

[BX Bandit]

It is wierd it only appends when hot, but that is exactly how mine is, on three different bxs. In fact, you know the juice is getting there because the click is the solenoid kicking in, but it's not making contact internally

[electrokid]

It'll be the solenoid sticking on the starter motor, usually worse in hot weather.

Very likely.

And (apologies for mentioning the curie curve twice in one week) the sticking is usually caused by muck in the solenoid housing and the amount of magnetic force available to overcome the grubbiness will reduce with increasing temperature.

And... that force will be futher reduced due to further temperature increase if starting is attempted many times in one 'session' without success because of the heat generated by running current through the solenoid.

If you have tried to start it several times without success (in one session) then you could try to feel (carefully) the temperature of the stater solenoid - the tubular assembly on top of the starter motor.

If that is very hot then wait for it to cool down before trying to start it again. If you're stuck somewhere and you are near to shops then buy a bottle of water from the cooler and pour it over the solenoid - if that gets it to start ok then it almost proves that dirt in the solenoid is to blame.

I say 'almost' because the same symptoms can happen when the starter motor brushes are on their very last legs in which case a replacement starter motor is the only real option.

[kiwi]

Thanks everyone, all sounds a bit technical for me to attempt myself! Hopefully Rohan will have a better idea than me! I've been meaning to change the battery terminals anyway as they keep coming loose and jumping off the battery, bumpy Scottish roads certainly aren't helping that problem, hopefully between the 2 of us we'll manage to go through the checklist. Either that or il be chasing the shaded spots in the carpark all summer

That would not be helping in the slightest!

Experiances of my own have shown a loose battery terminal can show up in many illusions of a fault that are magically cured by decent battery terminal connections. Recently been replacing the original lead connections with need terminal connectors making all the differance.

[Tinkley]

My experience of the starter brushes 'going' were slow turn over on the key. Several attempts with the key to turn the motor then it would go. The solenoid would kick in but the starter was unwilling to turn. A couple of turns of the key later and it would go. It's kind of 'fading away' a bit is about the best description I can give of it.
BTW depending on your starter motor, new brushes are available as I had to put some on mine at £1.78 for the pair it was a lot cheaper than a replacement starter motor. The solder joint to the the starter body terminal is a bit of a pig to get really solid so get a good lot of thick solder wire and keep the terminal clean (with file) as even with correct flux it still doesn't want to 'take' well. I nearly resorted to silver solder but the braid was already contaminated with the normal stuff at that point.

My neighbours Audi A7 is giving all sorts of weird problems. 'Expert' opinion is new gearbox, new ECU, mine was have you checked the battery - it is 6 1/2 years old. You don't need a lot of drop in voltage or charge back from voltage regulator or a bad earth to give some very very odd things. The only other weirdo thing is when you get a shorting ignition switch, mmmm very odd things can happen when the circuits get crossed. I don't claim to be an expert btw, it is usually just going through all the logical steps and my inclination is start from the bottom especially if it is cheaper!!

[citsncycles]

If the battery terminals are loose, that really won't help. The Mk1 BX that Citsandcycles has went through a very annoying phase of going dead when trying to start. Sometimes the third or fourth attempt would result in success.

I did eventually get to the bottom of that, and although the cause was very specific to Timex, it could be something similar.

In my case, there's been some interesting additions to the under bonnet wiring, effectively bypassing the original small diameter wires to the starter. The original wires are still there loose, and I eventually discovered that they would occasionally short out, giving the electricity an easier path than the starter.

In your case, it could be some damaged insulation where the wiring passes through a bulkhead, occasionally shorting out when you try to start it.