New Alternator now idling rough

[Rutherford]

I installed a new alternator today. The bearings had been bad on the old one for awhile and I final figured out that's what was making the strange noise. Anyway got a Bosch alternator from NAPA, installed it, no big issues but now the car idles rough. When I give it gas it sounds fine. When I first cranked it up it sounded OK. I let it run after I first cranked it up for awhile with the headlights on. Turned it off and after that it started idling rough. I rechecked the connections on the battery and alternator. I checked the belt. It seems to crank fine but idles rough. So what's up? If the alternator is not charging the battery would it do this? How can I check the alternator? Need to get to work Monday...any help would be greatly appreciated.

[Rutherford]

Oh by the way. Car has 292,000 miles on it. Only issues, Bad EVAP cannister (seems to be a Toyota defect), water pump and the airbag recall. Other than that I log 180 miles a day commuting. Transmission is still hanging in there but I should have changed the fluid before I did. Lifetime fluid they said and I did not know any better. I religiously change the oil myself with Castrol GTX. Alternator bearing was making noise for probably two years but was still charging.

[alanwagen]

Clean your throttle body may help some. When you disconnected your battery, the computer went back to factory specs and has to re-learn. It should right itself if a few days.

[Rutherford]

Yea I had read that after posting so I may just go out and drive it a bit tomorrow. It ran fine before the swap. I was wondering if there is a way to check the alternator output easily just to make sure. I have a multimeter but I will be the first to admit I am no genius with it. I disconnected the battery during install as directed. Hardest part was getting the belt back on and getting that little 10 millimeter screw off of the AC line mount off to pull the bottom alternator bolt out. I finally got the wife out there to hold the belt in place while I routed it over the pulley. I was dripping sweat all over her, she just loved that!

[alanwagen]

By chance did you bend or break the oil control valve sensor which is right in line to where you want to pry against to tighten the belt. Any lights on the dash?

http://www.yarisworld.com/forums/sho...l+valve+sensor

[Rutherford]

No I don't think so. I was careful as I have replaced the belt before. It has an electrical connector on it right (did not see one in the photo)? Looking at the link I use a bar and get below it from the side to pry - not from above. I went back outside and double checked and it looked good.

[Rutherford]

No lights on in the dash

[WeeYari]

ECU relearning, 'nuf said.


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[Rutherford]

Yep I think you guys are right. Cranked her up this morning, idle good. Took a 15 mile ride to the store and back with brights on, wipers going and on the way back I added the defroster on high just to make sure she was charging. Think I am good. Cross my fingers as she is quickly approaching the 300,000 mile mark. Many of you probably don't remember buy a few years ago I posted where this car had to traverse basically a 4-wheel drive gravel road 4 miles up and 4 miles down a mountain in the Blue Ridge. Worst road in the county and she is still going. I moved from that house in September so her ride is easier now.

[Rutherford]

Oh and yes many thanks for all your quick responses. This site is great and I need to write the guy with the you tube yaris alternator bearing recording as he led me right to the problem. The screw driver method for tracking sounds is another good trick. Better than what I use to do with a short piece of tubing. Thanks again.

[WeeYari]

Originally Posted by Rutherford

you tube yaris alternator bearing recording as he led me right to the problem

Post link. I don't feel like searching for it.

[alanwagen]

Wow, 300 K is awesome. 300 more??

[Rutherford]

Try this:

https://www.youtube.com/watch?v=eK4G0qran3M

[Bluevitz-rs]

Check the voltage at the battery with the car running. Should be in the neighbourhood of 13.6-14.6V

[valchrist90731]

Might be a defective alternator or bad internal regulator in the alternator.
Set your multi meter to volts and check reading on negative and positive terminals.
14.6 is great.
If your running the car and its in the low 13 volts return alternator and get a new one. Check battery by itself when car is off it should read 12.6 volts. That is a healthy charging system.

It's been said but once you remove the battery from the car it will ride rough for a little while.

After taking off your battery for these new cars for minor repairs, don't take your car in for a smog.

It will fail smog inspection.

[shepd]

If you want to be certain your car is ready for an OBD-based emissions test (rather than a tailpipe test) buy a slightly-better-than-junk OBD reader. Check that all the monitors show as "ready". Sometimes it will take as much as a full tank of gas to get them there. Of course, you also need no codes to show up.

If you want to get technical, find out how many monitors can be not ready in your state and still allow you a pass. Sometimes this way you can... hmmm... "cheat" by getting the car to the point all monitors but that one are ready if that monitor causes throws a code.

[nookandcrannycar]

Originally Posted by Rutherford

Yep I think you guys are right. Cranked her up this morning, idle good. Took a 15 mile ride to the store and back with brights on, wipers going and on the way back I added the defroster on high just to make sure she was charging. Think I am good. Cross my fingers as she is quickly approaching the 300,000 mile mark. Many of you probably don't remember buy a few years ago I posted where this car had to traverse basically a 4-wheel drive gravel road 4 miles up and 4 miles down a mountain in the Blue Ridge. Worst road in the county and she is still going. I moved from that house in September so her ride is easier now.

Yep. The same thing happened on my blue Yaris after a battery replacement. I posted about it and CTScott replied, writing to drive it around a bit because (as Wee Yari indicated above) the ECU needed to relearn the fuel trims.

[bronsin]

The wifes battery in her 05 Camry went bad a while ago. I put a new one in but after a few days at work the car wouldn't start. I figured alternator but her brother in law, a BMW mechanic went to the car and checked the voltage and pronounced the alternator fine.

We're guessing it had something to do with the learning curve of the computer but we're not sure.

The more "advanced" and "safe" cars become the more headaches sometimes!