Shuddering, Shutdown -- alternator?

BDE

New member
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!
 
Register to hide this ad
1) don't go to that dealer anymore, they sound horrible

2) I don't think you can determine much by the 12.9 vs 13.3v analysis. Perhaps take it to a place that can test the alternator directly.

3 or 4 batteries on a car that new? Do you have a Costco nearby? They will give a full cash refund even 3 years later without testing the battery. No questions asked and you can always use the cash to get another die-hard battery.

Btw do you now have a CEL lit up, has that happened recently?
 
Thanks for your reply, I really appreciate it!

I do not have any indicators lit up on my dash.
 
I don't know how much this will help. Years ago I had a 98 Nissan Pathfinder that had the shudder, shakiness when low idle or starting then one day did not start. Come to find out it was the Idle Air Control valve. It was defective but did not throw a code luckily I had a buddy at an Infiniti dealership that helped me narrow down the problem. It was a PITA to replace as at the time I did not have a place to work and limited tools but it took care of the problem. Again different makes/years but thought it was interesting that symptoms were similar
 
An Update

Before taking my vehicle to the shop (I will do that tomorrow), I took my multi-meter 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?
 

Members online

Forum statistics

Threads
278,309
Messages
3,554,075
Members
248,016
Latest member
Advally Service

Trending content

Back
Top