Just started doing this about a week ago(still happening ). This happens quite often, atleast every other startup. Got the battery and starting/charging system tested and it is good. Did a compression test with good #'s across the board and fuel pump primes. Changed the plugs the other day when I checked compression and still the same problem. No CEL codes either. I have plenty of fuel in the tank. Also changed the cam position sensors. Checked grounds as well. Hopefully you guys can help me figure this problem out as it has been a real big headache. Thanks
[media]http://www.youtube.com/watch?v=kuhH9rPxjt0 [/media]

 

[media]http://www.youtube.com/watch?v=5euqQnWuD28 [/media]

 

2nd vid was from today, other from yesterday. In the 2nd vid, you can hear it turn over then make a loud knock sound then die.

 

Can anyone confirm if that's what the dead alternator dash blink looks like? (not saying it is that failure but I'm guessing that's what it looks like)

When you had the battery tested was the battery itself warm or cold? Fe, did you drive to the test location with the battery in the car then test it? I had a battery test ok but not start very well on cold mornings because of that.

 

Check to make sure your battery is holding a good charge and test the 'load' while starting up the motor. If you did a test without trying to start the car this could give you a false 'ok'. when in fact there isn't enough amps left in the battery to start the car.

If you have a second car, a simple way to test would be trying to jump start the car. If it springs to life it's your battery/alternator and you'll need more testing to find out which.

Batteries are good for 3-5 years and alternators are good for a long time.

 

I will guess alternator or weak battery.

 

that's either a dead battery, or the negative cable being attached to the firewall by only a few strands.

funny enough, today we had a car with a similar starting problem and the battery kept passing the tests. After much testing replacing the battery stopped the problems.

 

The battery was tested with the car hot. Drove it up to the parts store. Dont understand the knock it does when it turns over on the 2nd vid.

 

My very first thought from your video was your battery.

Did they test the charging voltage when it was running, or did they test the cranking amps while you were trying to start it?? My guess is that your CCA cold cranking amps are really low...

 

And the car started ok after the test as well? Basically you tested the battery when it was working. In my instance they put a tool on it that put the battery under load to simulate a start condition - still passed that test but I resolved my problems, which I thought was a dead battery, by replacing it. Those tools aren't always right.

- most likely the battery because it only happens when cold