car problems...

[VJ]

Hello,

Saturday, I ran into some car troubles: it refused to start. Starting was attempted, but the engine just didn't turn over... (this was after a 15 km drive, followed by a 2 hour pause)

I called someone, who came with jumper cables, but we tried first another time without them: it started (with some difficulties). I then drove 2 km, had another 2 hour pause, and had little difficulties starting the car (it made an odd noise, and didn't start a smooth as it normally does).
During the difficult start, only the battery warning light lights up (but now I'm in doubt whether or not other lights also light up normally); while driving no warning lights are lit.

For the time being, I'm now using my parents' car (they are on holiday, my dad was joking "I filled mine up, in case you need it"), but I'm wondering what might be wrong (I'll only be able to go to the garage with it in 3 weeks time!). The car is a 4-5 year old VW Polo, fuel, automatic gearbox, ALWAYS sits outside...

We are thinking: battery (but then it wouldn't try to start), alternator or startmotor (last one most likely IMO)...


Thoughts?
(I feel I have had too many minor annoyances with this car in the last 6 months)

Jörg

[Brian Ellis]

The first thing to try is to remove both battery leads, scrape the lead posts gently all the way round with a knife, place the leads back on the battery but before tightening them, twist them round back and forth a few times, to seat them well down and only then tighten them. Corrosion on the posts is a common cause of such failure. If that doesn't work, then have the battery checked for high current Ah capacity; this is, by far, the most likely cause, especially if it is the original one after 4-5 years in all weathers. I would rate the starter motor as the least likely cause.

[VJ]

I would expect the car doing nothing when the problem lies with the battery... Or are cars already very critical regarding the power delivered by the battery?


Jörg

[Marshmallowman]

The thing with car batteries is that you might get one cell going bad, so while it may crank over quite well(amps) the voltage may be to low for the ignition system to fire up the engine.

You could check the battery voltage with a multimeter after it has been sitting for a while as a check, but even then you can't be sure.

It would be a good idea to try your parents battery for a while (if it is compatible)

But anyways, if the batteries are over 3-4 years they are always a suspect.

[Brian Ellis]

I would expect the car doing nothing when the problem lies with the battery... Or are cars already very critical regarding the power delivered by the battery?


Jörg

The Ah capacity of a battery drops as particles of lead oxide paste fall out of the lead grid. The voltage could still seem OK, but if there is insufficient current-carrying capacity and the starter motor stalls, it is almost like a short-circuit and the battery goes flat very quickly. Another fault is the particles of paste falling to the bottom can almost short-circuit the plates, self-discharging the battery. The average life of a car battery is less than 4 years, especially when winter temps can drop below 0°C.

As I said before, the battery is, by far, the most likely cause.

The idea of swapping with your father's battery looks most attractive (especially if you don't tell him!!!!!!!!!!! )

[cjolley]

My vote goes to battery too.
If your battery is over three years old it might be cost effective to simply buy another one and install it yourself to see if that fixes the problem. you'll be replacing it soon anyway.

It may be different elsewhere, but here in the US most large auto parts stores will test your charging system for free.

I had a battery go bad by having a plate break off inside it once.
It would work fine depending on the angle the car was sitting at as the plate flopped around in the battery case.
Very frustrating trying to track that one down.

[Fat Tone]

I'm surprised at the lifetimes you quote. I've never had a battery last less than seven years, and usually closer to 10.

[VJ]

I'm not sure the battery of my dad's car would fit. It also is a fuel engine, but it is a Volvo 5 cilinder, 2.0 l, 20 valves engine (Volvo 850); his battery looks bigger...
(besides, I now have a reason to drive around with that Volvo, so why bother? )

The funny thing is that last time when they went on holiday, I also ran into car issues and had to use their car for 2 weeks. Feels like there is a pattern emerging...

Still, I'm relieved the engine is the most likely culprit...
If so, I am disappointed by the short life of the battery, as I travel quite long distances (sunday: 200 km in one go, workweek 2x 20 km per day, friday again 200 km in one go), giving the battery plenty of opportunity to recharge.


Jörg

[Brian Ellis]

If so, I am disappointed by the short life of the battery, as I travel quite long distances (sunday: 200 km in one go, workweek 2x 20 km per day, friday again 200 km in one go), giving the battery plenty of opportunity to recharge.

Or to overcharge! How often do you check the levels in the battery? And think of the vibration of 600 km/week shaking the paste out of the plates. In reality, the life of a battery is dependent on many factors and the no. of kilometres is one of them. The last one I changed was after 8 years but it had been correctly maintained in a car that averaged only 8500 km/year, was kept in a garage and never knew cold weather conditions.

[rylan]

Also if its the original battery then 4-5 years is plenty for it to go bad.

[cjolley]

Also some of them are just clinkers.
That's why they come with guarantees.

BTW how old is it?
They usually have a date somewhere on them.

[gt40]

turn the lights on, try to start it. If the light dim appreciably, then it's most likely the battery. If the lights remain fairly bright, but it still struggles turning over then it's the starter.

[VJ]

Dunno if it is related, but in the past (car has always done this), the lights dim when I turn the steering weel. This is very noticable in a parking garage.

The 600 km per week is all on very nice asphalt... Guess I'll only find out in a few weeks time.

For now, I don't have access to the car till this weekend, but I'd rather leave it: if I only manage to start it once, I'd like to use that start to drive to the garage.


Jorg

[Gurm]

If the lights dim when turning the wheel, then the power steering pump's drain is too much for the rest of the electrical system... which leads me to recommend that you trace through the electrical/charging system.

Could certainly be the alternator, but do as Brian suggested and rule out the battery first.

If it were the starter motor, you'd hear a nasty grindy whirring sound when you turn the key, or perhaps NOTHING if it were totally dead. You haven't done the embarrasing task of describing the noise it makes yet... *grin*

[degrub]

When the lights dim while turning, the engine is probably idling, and the PS pump is taking more power from the engine via the belt , so it slows down and the alternator doesn't put out as much current.

You can test this by the obvious, but be carefull, you don't want to hit anything if you loose control

IF it is a manual then just feather the clutch and rev the engine.

I've had starters (850T5) ( not the solenoid - which is when you get the Whirrr or Grind but the starter motor itself) that would loose power in the middle of cranking, and start right up next crank.

BTW which 850 is it ?

The other thing that can do this is either a relay used between the starter switch (key) and the starter solenoid/motor or the contact pins on the back of the key pod (where the key goes in) . Sometimes the springs on the contact pins wear and don't return to position or there is fouling on the contact surface. If you are lucky you can wiggle or rotate the key several times and it will work. Or maybe a sharp rap on the back /side of the key pod. VW used the relay method on all of my old VWs (Quantum, Jetta, Cabriolet).

VW also had a problem with a plaque forming on the power wire to the starter and solenoid - had to clean them several times and then sealed them over when i got tired of it. This would cause exactly what you describe - it would start when hot but not when cold or after a few tries, but not the first time. They also had an extra connection point in the current path to the starter - fix was to run direct cable to starter in parallel.