So the mini-sooperkia has developed an odd... habit? Once in a while, while turning right and accelerating in second gear the battery/voltage light will come on for 1-2 seconds and go off. It took me 4 days to figure out what it was as it's a little red light coming on behind the turning wheel and I'm multi-tasking at the time. but from what I can determine it only comes on when:
Turning right, usually from a slow or stop.
Accelerating past the 3k shift point the ECU deems sufficient for accelerating
2nd gear. Not 3rd, not first. Only second.
Most occurrences happen in the first 5 minutes of driving.
I can't get it to do it consistently. I've checked all grounds. I've checked the alternator wiring (this one is right on top so a change looks fairly simple). I've checked the positive cables. The battery looks to be about 8 months old.
My working theory currently is possibly a loose plate in the battery that with the right movement/load it creates a momentary short? Other than that... how the hell do you diagnose something so random and inconsistent?
2nd only makes me think the transmission linkage somewhere is hitting a ground strap between the engine/trans and the frame. I don't have a good idea of how to figure this out further.
How do you diagnose something so inconsistent and intermittent?
Well, for starters, it's not inconsistent. You've been able to define a predictable "when". Doesn't do it all the time, but you know when it's likely to happen.
Because it's an electrical issue, next up is a scope. I like scopes, even for purely voltage related things like this, because they're a logged voltmeter. So I'd connect a scope up to, say, the voltage signal to the alternator light, and the horn circuit. Why horn circuit? Because you might be out there trying to get it to act up for a LONG time, so when you see it act up, hit the horn. Then you can go and look for the horn voltage spike/drop and then look at the other channel to see if there's anything to see.
I have never seen nor used a scope. I can get it to act up once in a hundred at most.
Do you have a voltmeter hooked up? Run one. Or a few. In different places and see if they reflect the same issue. They might show you that it is acting up more often than you realize.
OK, maybe I should have mentioned this is a 2013 Kia Rio. I'm not hooking up a volt meter to it and running around all F&F style. Trying to keep the car nice.
It is going to be difficult to do any electrical diagnostics without a voltmeter, and the 2nd gear only is weird ... but I would think its an alternator on its way out.
If it was me, and this is not the wife's car, I would keep driving and ignore until it becomes worse. It will probably make it easier to pinpoint the cause.
In reply to Slippery :
that's kinda where I am at. I have a spare battery that came from the wife's car. I might swap it over (it's a known good one) and just drive it.
bobzilla said:
OK, maybe I should have mentioned this is a 2013 Kia Rio. I'm not hooking up a volt meter to it and running around all F&F style. Trying to keep the car nice.
That's what we end up doing when doing intermittents, or any other number of diagnostics really. Meters and scopes and stuff everywhere.
Honsch
Reader
5/15/21 6:03 p.m.
This definitely sounds like an engine movement induced problem.
Just because the wires look OK doesn't mean they haven't been flexed to breaking somewhere inside the insulation.
What condition are your motor mounts?
Engine movement?
Worn engine mount?
This was going to be my early guess too.
Since you have that other battery, that swap is a great idea too.
Swapped batteries Sat afternoon. Drove the car 4 times and it hasn't tripped the light yet. Now, the next question IF this "fixes" it, was it a battery issue or connection issue? They'd just replaced battery when we picked it up so it's possible it could be a connection issue. I'll keep monitoring it for now.
That's good news.
I would assume connection for now. If it reoccurs in a few weeks I'd suspect the alternator not being able to keep the battery topped off.
In reply to Honsch :
Mounts look really good. The car is just over 80k and it appears it hasn't really been beat on before me. There is engine flex, and I am thinking about the Evillamotorsports lower trans mount insert.
Lazy 'scope' = OBD2 logger. Cheap and easy. I did it on my Saturn and it was pretty effective. I found there were certain situations where the alternator wasn't putting out enough voltage (mainly idle).
bobzilla said:
OK, maybe I should have mentioned this is a 2013 Kia Rio. I'm not hooking up a volt meter to it and running around all F&F style. Trying to keep the car nice.
No offense, but if that is the case, time to just give up and live with it until it gets noticeably worse.
I have seen low fluid level or bad PS system or a marginal tensioner cause similar symptoms. You end up getting belt slip due to the high load and the alt can't charge with the RPM going low.
In reply to Paul_VR6 (Forum Supporter) :
Electric Assist PS so not the issue in this case unless the load is overwhelming the alt.
EDIT: as for load I've literally run everything. lights on high, wipers, A/C, fan max, stereo etc. Can't make it happen
problem not fixed. In fact this morning it came on once, but flickered on and off from 3500-5000rpms. Looking at the belt I am ordering a new one. Its original with 90k but it's a bit shiny.
Just wanted to update this since I know so many were dying for an update..... It's fixed. Belt was the issue. installed new belt, ran it in, retightened (manual tensioner) and it's not been back on since. YAY! cheap and easy fix.
