arielsdv
11-05-2014, 11:03 AM
So this site (thanks to its members) has helped me so much that I felt compelled to take a few minutes and contribute.
Background of problems with my '04 ZHP:
Car started momentarily shutting off (we're talking a split second). When at highway speeds this was not an issue as the car would quickly recover and continue running as if nothing had happened. The only lights that would come on were the battery and oil lights (I dismissed the oil light because this could easily be attributed to the fact that the oil pump stops working as the engine stalls).
Anyway, the problem started to get worse to the point that other lights would flash along with the stalling event. The lights would be random: things like DSC, Brake, EML etc. These lights would blink ON along with the stall event and in different combinations and at different times. Eventually, the stall event was so pronounced that the DSC/Brake lights would just stay ON (i.e. turned DSC system OFF).
After reading a ton of posts, people recommended a multitude of areas that could've been the culprit. Things like: bad sensors (crank or cam), spark plugs, bad fuel pump, bad fuel filter, bad upper/lower intake boots, bad this and thats, etc...
The problem was that there were no codes that would point to any of those things (I used a pro computer, not your standard Autozone code reader).
To make a long story longer, I went ahead and replaced the Spark plugs, Fuel filter, Fuel pump, Oil level sensor (just in case that light I mentioned earlier was not a fluke). I checked the boots, cleaned the MAF sensor, checked the voltage of the battery with car OFF (12.5 VDC), checked the voltage with the car ON and with a load (13.7 VDC).
At this point my options were: 1) take it to the stealership, or 2) throwing parts at the car until the problem went away (I hate this approach for too many reasons, namely cost, and the ignorance of not knowing the root cause). I found a buddy who is friends with a tech at the dealer and decided to buy them lunch and pick his brain. I told the tech (one of the lead techs at the dealer btw) all my symptoms and what had been done and after learning the history he said "I would check the alternator first". I asked "why"? having done the alternator/battery check myself and he said "did you check for AC voltage?"
He said that it was unlikely it was my battery because it measured 12.5 volts at rest and because the car starts without any problems. He advised to take my multi-meter and set it to measure AC voltage (not DC), and I should see no more than .02 volts and that anything higher than that could drive the DME crazy with random lights, codes, misfires, stalling etc..
So there you go! turns out he was spot on.. I never once read any posts where anyone mentioned checking the diode-rectifier pack on the alternator by running an AC voltage check so I figured I'd share and hopefully help out someone with similar trouble.
Cheers!
Background of problems with my '04 ZHP:
Car started momentarily shutting off (we're talking a split second). When at highway speeds this was not an issue as the car would quickly recover and continue running as if nothing had happened. The only lights that would come on were the battery and oil lights (I dismissed the oil light because this could easily be attributed to the fact that the oil pump stops working as the engine stalls).
Anyway, the problem started to get worse to the point that other lights would flash along with the stalling event. The lights would be random: things like DSC, Brake, EML etc. These lights would blink ON along with the stall event and in different combinations and at different times. Eventually, the stall event was so pronounced that the DSC/Brake lights would just stay ON (i.e. turned DSC system OFF).
After reading a ton of posts, people recommended a multitude of areas that could've been the culprit. Things like: bad sensors (crank or cam), spark plugs, bad fuel pump, bad fuel filter, bad upper/lower intake boots, bad this and thats, etc...
The problem was that there were no codes that would point to any of those things (I used a pro computer, not your standard Autozone code reader).
To make a long story longer, I went ahead and replaced the Spark plugs, Fuel filter, Fuel pump, Oil level sensor (just in case that light I mentioned earlier was not a fluke). I checked the boots, cleaned the MAF sensor, checked the voltage of the battery with car OFF (12.5 VDC), checked the voltage with the car ON and with a load (13.7 VDC).
At this point my options were: 1) take it to the stealership, or 2) throwing parts at the car until the problem went away (I hate this approach for too many reasons, namely cost, and the ignorance of not knowing the root cause). I found a buddy who is friends with a tech at the dealer and decided to buy them lunch and pick his brain. I told the tech (one of the lead techs at the dealer btw) all my symptoms and what had been done and after learning the history he said "I would check the alternator first". I asked "why"? having done the alternator/battery check myself and he said "did you check for AC voltage?"
He said that it was unlikely it was my battery because it measured 12.5 volts at rest and because the car starts without any problems. He advised to take my multi-meter and set it to measure AC voltage (not DC), and I should see no more than .02 volts and that anything higher than that could drive the DME crazy with random lights, codes, misfires, stalling etc..
So there you go! turns out he was spot on.. I never once read any posts where anyone mentioned checking the diode-rectifier pack on the alternator by running an AC voltage check so I figured I'd share and hopefully help out someone with similar trouble.
Cheers!