Edit: Car is at 162 thousand miles

Hi. I've been pounding my brain at this for the past 2 days and am finally ready to ask for some advice.

My CEL codes are P0445 and P1448 (the loose gas cap codes, this is from memory. Battery is pulled out of car and is on the charger in my basement.)

For the first time, my charging system light came on about a week ago - I came up on traffic on the highway outta nowhere and had to slam on the breaks. This immediately lit up my dash, Charging System and ABS light came on - the traction control said it also shut off at this point.

Yesterday, my car lit up with those again out of nowhere. The car seemed to be running fine (it does have a misfire), but all and all, it did alright. Until the part where my entire dash lit up.. Air bag light was flashing, a bunch of random lights came on as well. The engine sounded REALLY bogged down at this point, and trying to get the car to accelerate made me scared I was about to blow the motor, so I parked the car and shut it off - it wouldn't start again at that point.

When I came back to have it towed after work, the car started, but quickly did the same thing again.

Our thought was the ECU, so we unplugged the battery for the night, had autozone load test it and it's fine.

When we put the battery back in the car earlier today, she started right up and I got four miles out of it before it did the exact same thing.

Thanks guys!

 

I keep reading that you are getting the battery recharged. What you need to do is get out your voltmeter and do some voltage checks.

1 - after the car has sat parked overnight/several hours, check battery voltage. A good battery will be 12.5 volts give or take a tenth.

2 - Start the car and check the voltage with the engine idling. A good alternator will have the voltage at 14 to 14.2 volts.

3 - Turn on everything you can, lights, heater fan , rear window defogger, a/c, etc. A good alternator will have the voltage at 14 to 14.2 volts while the engine idles.

Let us know the results.

 

My old man recommended I take the alternator into autozone earlier today to have it load tested as well, will this serve the same purpose? The only way I have to check the voltage on the battery is while it's on the charger in the house.

We also bounced the idea around that maybe my throttle body needs cleaned out.

 

Yes, but why bother to take the alternator out? Why not do what Dennis suggested - his advice is the best solution of all.

 

Not sure if this is related but last week I was on an intermediate highway (50mph spees limit with lights) and it turned yellow, i got a ticket going through a yellow before so Im paranoid about this so I braked fairly hard. not to the point where there was screeching or crap flew forward in the cabin just a swift smooh stop to the light. When i got there (was playing loud music) noticed dash warning lights were on. Thought it was weird but went to hit the gas and nothing, engine died. Went **** and was sitting dead in the road, electrical flow was never disrupted because music was playing fine loud thru subs. Figured out in about 10 seconds that i put in park and turned the key to restart but looked like an idiot at the green light. Still not sure to this day what happened, been fine since. 03 GLE

 

When you took your foot off of the gas pedal and applied the brakes, the sudden drop in engine rpm caused the engine to die. This will happen. It shouldn't, but if it is a one time thing, you will probably never know why.

The engine could need a tune up, or the throttle body needs cleaning, the TPS needs cleaning/adjusting or a lot of other things.

 

Theoretically having the alternator tested off the car will be fine. The actuality of it is that autozone is known for not being able to do things right. I have dealt with 4 different stores by me and gotten bad diagnoses on starters and alternators. One time my check engine light came on and I stopped at the autozone by my house to have them read the code. They can't screw that up, can they? The answer is yes they can. I was told I had a mis-fire on cylinder 8! I told the guy the car only has 6 cylinders and his response was "the machine doesn't lie." I knew that I didn't have a mis-fire, either. Went to an O'Reilly's and they came up with P1447, which was verified by Napa.

But telling you to measure voltages is a lot easier than taking off the alternator. If you intend to work on your own cars, invest $60 - $75 for a decent voltmeter and OBD code reader.

 

Well, it turns out it was the alternator. Autozone was my pick just because they're like... four blocks away. They load tested it and it failed, my battery passed the test the day before. Threw it all together and it fired right up exactly like it should. Several times in a row. With all the accessories on. And then it stayed on for a decent amount of time. There was a screeching but I wanted to see if it would go away. And it did for a brief second entirely... But then there was a god awful banshee wail of a nails on chalkboard sound that would make everyone on the road hate me. So I left for work and my dad took a look at it for me when he got home... He broke the bolt screw that adjusted the tension level in trying to get it figured out. I'm pretty sure it's the idler pulley at this point. Has anyone else had the same issue, and anything I should know going into the repair? I can't get back in to diagnose with any certainty that it's for sure the idler pulley, my dad took it off the car before I had that chance. Just hoping for some reassurance before I spend money on this. Already spent way too much money between the alternator, the belt and now probably the pulley.

 

My failing ac compressor clutch caused the serpentine belt to squeal horrifically loudly whenever the climate control was on. Replaced and sound is gone. bought a remanufactured one for 120 and dropped it in. No belt or pulley problem like i thought. Food for thought.

 

The secret to the idler pulley is that you have to loosed the locking bolt before you turn the tensioning bolt. The locking bolt is the bolt that holds the actual idler pulley on. Loosen the pulley bolt and then turn the tensioning bolt.

But the screeching could also be a loose or worn belt.