Coil packs frequently going bad

I hope so too cause its getting irritating. Popped a new coil in today and running like a top.

 

Brand new battery as of 2 weeks ago. Battery was toast and grounding out getting hot

 

How old, how many miles in the plugs?

 

they simply check for a range of voltage output under a certain load. I’m not sure a single phase diode would be detected or not by their test. I think it’s a go-no-go type of tester so they don’t have to interpret any data.

excessive heat up of house battery. In theory the battery will act as a large capacitor and filter this noise out but if the noise is large enough it cannot suppress it all. Other components that rely on PWM switching can be seen affected, maybe something like fuel injectors, VSV, or purge flow for the EVAP come to mind. Aside from that there won’t be many symptoms but noise will degrade the life of components designed for clean DC power. i would put a scope on the output of the alternator to eliminate this as potential cause. There are numerous other things as mentioned earlier that could also be a cause of failing, there is also a noise filter right at the coil pack circuit to try and prevent this from occurring but this could also have gone bad from excessive spikes due to ripple over time.

 

If the battery was shorted out for a bit, check the alternator closely. That doesn't mean take it to autozone for a free test, I mean take it to a shop that can scope it and make sure it's not affecting the pcm

 

make sure its all oem. replace pcv valve and clean throttle body and maf and iacv

 

Good info. I leaned something there.
Never would have thought of if affecting the PWM.

 

I have seen bad batteries and alternators trigger false codes many times without other symptoms, usually low voltage codes will be present as well but not always.
Had a Chevy Traverse just last week that was setting all possible codes for all 4 oxygen sensors as well as a PCM internal memory error code, turned out to just be a bad battery.

 

I don't own or have access to a true oscilloscope but I have a Fluke 117 multi meter anything I can do with that?

I recently had a battery go bad with a weird intermittent weak/bad cell, basically it would act like a dead battery on the first crank then after drawing amperage on it it would start the truck just fine on the second crank. (AGM 24F Northstar) O'Reilly's machine said it was just fine but my Uncles Snap On digital scanner said there was some kind of issue.

Wonder if my alternator is on it's last leg, 11 years 250k miles wouldn't surprise me too much but otherwise everything is peachy, just don't want to kill my new 27F AGM Northstar, things ain't cheap.

Lastly I've heard AGM's need voltage boosters but when looking at my scanner with the truck running voltage seems to be right where is should be 13.6-14.1v neighborhood.

 

you can put it on AC and check the alternator output and see what ya get, but those type of meters use an averaging circuit over time and not really intended to detect small amounts (mV) of ripple. Personally and my rule of thumb I’ve used for many years with electronics, I believe anything over 300 mV is time to start looking at your VR for repair/replacement assuming steady state operation at nominal load. Ripple will tend to increase the further you load up a supply.

it sounds to me like you had a cell shorting out intermittently. What happens is that the “sluff” that collects on the plates falls off inside a battery cell and slowly connects the positive and negative plate over time, known as sulfating or sulfation. Once it shorts out it burns this off and the battery is back to full voltage but only for short periods of time. If you have a good charger, desulfating will pulse the battery with short bursting waves of AC voltage to bust up the “sluff” and extend the life of the battery for a bit longer.

An AGM battery is not susceptible to this long term degradation due to difference in design. Read up on IEEE 450-2010 if you get a chance, lots of great info in there if you choose to keep a flooded lead acid battery.

 

It is also true that an AGM battery requires a higher charging voltage due to a higher OCV. these will usually be specified by the manufacture of the battery and you can use a voltage booster for your alternator to raise the charge voltage to the battery as required. Here is example from optima website

 

If you have a multimeter, with the truck running, check for AC volts across the battery. If you got any, you've probably got a bad diode. AC riding on the DC can do some damage to electronics if it's too high.

Also, these alternators, tend to whine when this happens and will usually increase as the load on it increases.

Good luck.

 

Update

So i have all codes cleared currently, was indeed the upstream o2 sensor, soon as truck started you could hear it running better. Code went away.
Fingers crossed it stays gone.
Talked to a few shops all seemed to say because it being an AF sensor as well is why i always have issues on that bank and not the other side. We shall see ill let everyone know if it changes

 

@Key-Rei that's a decent meter. I'd suggest getting an amp probe for it.

Something like this, rated for both AC and DC