Following on from two previous topics reguarding high idle on start up (i posted a video on my other thread) we made some progress reguarding the battery maybe?

Well today i done a drop test on the battery and it came back as pass and showed 12.4 volts... The drop tester checks each cell in the battery ans gives pass, weak or fail results, as well as a voltage.

I then checked the output on the alternator, i got 12.2 on start up idle at 800rpm and then wen the high idle started (just over 1000rpm) it dropped to 12.0 and kept going between the two.

Its been doing this for a long time now and the car always starts no problem, lights dont dim when powerd steering is used etc.

So how am i getting a low output on what really is a knackard alternator, yet have a good strong battery still?

Just checked mine with my multimeter and it was as follows:

Engine off battery gives 12.1v

Engine running 14.4v

Brilliant, thanks for posting your results!

My alternator must be on its way out i guess... strange how i i've still got a good strong battery.

One thing i didnt check was the alternator output over different rev rages.

Not a problem, although I can't rev and hold my multimeter at the same time! :p

Should an alternator be on the way out at 57k? Sure the one on my Octy was still going at 100k, not 100% sure though. As noted previously, mine sounds like it does exactly like yours, although I have noticed the lights flicker SLIGHTLY when doing big steering changes at lowlow speeds, ie reverse bays. Done quite a few late night ones of them lately .

Dont think alternators are common on our cars tbh but the idle fault does seem to be common... I have loads of new batteries at work so a quick test might be to fit a few one when i can be botherd to test it.

Edited 15 November, 201213 yr by hutchysrs50

Ahh, forgot you were an Ibiza, apologies. Alternator may be same being similair age/chassis etc, but no idea in all honesty.

Watched your vid, exactly how mine does it. If you turn it off after it starts rising the revs and turn it on again, does it do it then ?

Also, if my car sits for a day or 2, it seems to take an extra crank to fire up, so may well be something in battery/alt arena.

Edited 15 November, 201213 yr by Iann-

Yeah mines an ibiza fr, same as a fabia vrs, hence why i still post problems on the skoda forum haha.

Mine does it everytime no matter what (exept that one time the other day) i can turn it on and off 10 times and it would do it every time.

Hmm.. Mine only seems to it on the first start up of the day, or if it's sat for 5+ hours. Although it done it the other day while I was sat at a rediculously long set of lights in the city centre.

I'm not mechanically minded, but more I think on it the more it seems to be an alternator issue. Doesn't seem to be a serious issue for now, so I'll probably not do anything about it for now, or at least untill the start of next year.