Shuddering / Shutdown -- alternator?
12-15-2016, 07:20 AM
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Shuddering / Shutdown -- alternator?
Hello Everyone,
I will try to summarize this as concisely as I can, but try to give any history that may be relevant. I have a 2012 Base Model 4WD Rav4 with about 40K miles on it.
Many months to a year ago I had a problem where the vehicle would shake/shudder sometimes at start time sometimes when I'm idling or going slow. It felt like the vehicle would shut off but it never actually did shut off. To me, the vehicle also took a bit longer to start than it used to after I turned the key. The dealer told me to change spark plugs which I did but I don't think it made a difference. Because the problem was intermittent it was hard to say if the spark plugs helped or if they were just changed at a time it was not happening often.
After the problem still reappeared, the dealer told me I had to clean my throttle body and they charged me for a cleaning. I also sprayed my mass air flow sensor myself which seemed to help a bit, too. The dealer did a terrible job of cleaning, but I also managed to get a mechanic to do a house call and clean the throttle body which was visibly very dirty.
Unbelievably, my dealer also forgot to replace the air intake filter, but I notice the RAV4 has a permanent filter which seems to be a good backup so hopefully no damage was done there.
I have changed my battery a few times over the past couple years and while it is under warranty and the battery people tell me it seems like I keep getting defective batteries, I have to wonder a bit.
I have installed a donnelly gentex auto-dimming mirror on my car (seems it went through fine), and I also was trying to troubleshoot some aftermarket fog lights and accidentally shorted the switch which cause some smoke and underneath the dash by the steering wheel column. I had an electrician check it and they say they could not find any wiring or electrical problems and I probably just burnt the insulation off the foglight wires. Lastly, I also installed a 2.1A USB charger in one of my accessory slots. I don't think any of these made a difference, but I could be wrong so I am mentioning them.
This weekend I could not start my car and needed a jump so I went straight to the battery store. After changing my battery again, the guy who changed it said he gets a strange "NO OUTPUT" from the Charging Test which shows 12.97V on both "loaded" and "no load". He says he thinks that this means the alternator is failing because he would expect 13.3V at least. I am not sure if that is right (13.3V), but the main thing is that the battery voltage is 12.97V and when the vehicle is on it is still 12.97V.
Now that I supposedly have a new battery, the car sometimes shuts right off after starting. I would say it happens less often at the first start of the morning than at the afternoon start when I go for lunch. Once its started, I do not notice anything but sometimes it shuts off sometimes it shudders like it will but doesn't shut off.
I am a technical guy the works with electronics but I definitely do not know much about cars or mechanic work aside from some theory, so I have a lot of respect for you experts.
Thanks!
I will try to summarize this as concisely as I can, but try to give any history that may be relevant. I have a 2012 Base Model 4WD Rav4 with about 40K miles on it.
Many months to a year ago I had a problem where the vehicle would shake/shudder sometimes at start time sometimes when I'm idling or going slow. It felt like the vehicle would shut off but it never actually did shut off. To me, the vehicle also took a bit longer to start than it used to after I turned the key. The dealer told me to change spark plugs which I did but I don't think it made a difference. Because the problem was intermittent it was hard to say if the spark plugs helped or if they were just changed at a time it was not happening often.
After the problem still reappeared, the dealer told me I had to clean my throttle body and they charged me for a cleaning. I also sprayed my mass air flow sensor myself which seemed to help a bit, too. The dealer did a terrible job of cleaning, but I also managed to get a mechanic to do a house call and clean the throttle body which was visibly very dirty.
Unbelievably, my dealer also forgot to replace the air intake filter, but I notice the RAV4 has a permanent filter which seems to be a good backup so hopefully no damage was done there.
I have changed my battery a few times over the past couple years and while it is under warranty and the battery people tell me it seems like I keep getting defective batteries, I have to wonder a bit.
I have installed a donnelly gentex auto-dimming mirror on my car (seems it went through fine), and I also was trying to troubleshoot some aftermarket fog lights and accidentally shorted the switch which cause some smoke and underneath the dash by the steering wheel column. I had an electrician check it and they say they could not find any wiring or electrical problems and I probably just burnt the insulation off the foglight wires. Lastly, I also installed a 2.1A USB charger in one of my accessory slots. I don't think any of these made a difference, but I could be wrong so I am mentioning them.
This weekend I could not start my car and needed a jump so I went straight to the battery store. After changing my battery again, the guy who changed it said he gets a strange "NO OUTPUT" from the Charging Test which shows 12.97V on both "loaded" and "no load". He says he thinks that this means the alternator is failing because he would expect 13.3V at least. I am not sure if that is right (13.3V), but the main thing is that the battery voltage is 12.97V and when the vehicle is on it is still 12.97V.
Now that I supposedly have a new battery, the car sometimes shuts right off after starting. I would say it happens less often at the first start of the morning than at the afternoon start when I go for lunch. Once its started, I do not notice anything but sometimes it shuts off sometimes it shudders like it will but doesn't shut off.
I am a technical guy the works with electronics but I definitely do not know much about cars or mechanic work aside from some theory, so I have a lot of respect for you experts.
Thanks!
12-18-2016, 02:07 AM
#2
Well since the battery reads the same voltage with engine shutoff or running .
That says something is wrong in the charging circuit !!
Could be a poor connection caused by something being loose something corroded more trouble shooting needs to be done.
Then you could just buy another alternator and hope you get lucky
That says something is wrong in the charging circuit !!
Could be a poor connection caused by something being loose something corroded more trouble shooting needs to be done.
Then you could just buy another alternator and hope you get lucky
12-19-2016, 06:57 AM
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An update:
Before taking my vehicle to the shop (I will do that tomorrow), I took my multimeter and tested my voltage across the battery terminals when I started up this morning (started great with no shuddering, etc.)
I turned on my radio, my air conditioner, my auto-dimming mirror with compass, I turned on my headlights and my fog lights, and I even plugged a smartphone into my USB charger!
The drop in voltage was minimal and it stayed around 13.8V.
If the alternator was bad, could it perform at such a high efficiency sometimes, or does this point more toward a relay or a loose connection?
Before taking my vehicle to the shop (I will do that tomorrow), I took my multimeter and tested my voltage across the battery terminals when I started up this morning (started great with no shuddering, etc.)
I turned on my radio, my air conditioner, my auto-dimming mirror with compass, I turned on my headlights and my fog lights, and I even plugged a smartphone into my USB charger!
The drop in voltage was minimal and it stayed around 13.8V.
If the alternator was bad, could it perform at such a high efficiency sometimes, or does this point more toward a relay or a loose connection?
12-19-2016, 07:14 AM
#4
Looks like you have partially isolated the problem to intermittent charging. Now just to figure out if it's the alternator or the wiring or both.
You need to find what smoked! You kind of hint it was just the fog light wiring but it's not perfectly clear.
You need to find what smoked! You kind of hint it was just the fog light wiring but it's not perfectly clear.
