Like you, I suspect the crank position sensor since it's the only thing down there close enough to arc to the balancer (dampener, actually). However, there shouldn't be much voltage going to it - most likely, the input reference-voltage is only 5 volts. I'll check my Vantage tomorrow and see if it gives a value for that sensor's reference voltage. The crank sensor drives the tach, and is the only input that tells the PCM the engine is running. If weird things are going on with the crank sensor, that explains the tach drop-outs and the alternator light (PCM thinks the ignition is on and engine is off).

I'd pull the sensor and check it for evidence of arcing - replace the sensor if you find said evidence. Maybe the sensor housing is cracked and is allowing an arc.

Do you have any high-voltage sources (like HID-headlight ballasts) that might be near enough to the sensor wiring to induce a higher-than-normal voltage on the sensor? Do you have any way to back-probe the sensor at the connector and capture transitory voltage spikes? To do this, you need a graphing multimeter/lab scope like a Vantage/Modis/Genisys (Actron has a low-cost equivalent) or one of the higher-level automotive multimeters/analyzers that has a rapid scan-rate, high input impedance, and high/low feature or glitch-capture. However, I suspect that if you had a crossover from a high-voltage circuit into the sensor circuit, you would have fried the ECM/PCM from the excessive voltage coming back in from the sensor and you'd be seeing other problems.

Let us know what you find!

on edit: Confirmed via Alldata that the reference voltage for the crankshaft sensor is 5 volts (DC, of course) - so, you should never see more than 5VDC on the reference/input wire.

 

Checked the gap on the crank position sensor and it was within the recommened gap .05". I then removed the sensor and it appears to be in good condition with no frayed wires or cracks. I cleaned it up and re-installed it. There is still an arc occuring from the dampener to the block on the botton of the motor with an audible click noise. All the gauges are working fine and the tach is preforming fine. I am stumped. Could something else have a bad ground that is grounding out through the dampener. I am ready to take it to a local cummins mechanic.

 

You can actually see the arc?


There is nothing on our engines that generate enough voltage to jump a gap like that. I believe you need upwards of at least 5kV to start jumping gaps easily.

The only thing that I can think of something is rubbing on the outer section of the balancer and generating a static charge (since it is isolated by the rubber ring). Static charges can easily develop large voltages.

 

Could there be a ground wire near there?If so maybe it's loose and not making a good connection.

 

The arc is clearly visible and I don't think there is a gound wire in the area. I checked and cleaned the ground wires on top of the motor which come out of the main wiring harnes but no change. Thanks for the advice I will let you guys know what I find.

 

Weird....Manual or automatic trans? I'm wondering if there is something in the bellhousing or trans rubbing on the clutch or converter building up a static charge. Everything else is isolated from ground by rubber. The CKP sensor definately is not the cause. The most voltage it has available is charging system voltage. A chit load of metal in the trans oil? Do you have any other symptoms? Noises, stuff not working right, anything? I'm very curious now.......

 

wow, thats a first... LOL

Like mentioned, it takes ALOT of voltage to start jumping gaps, and their is nothing on these trucks designed to produce that kind of voltage (unless like mentioned, it is a static type charge)

 

I'd want to fix the arcing asap

arcing means lot of voltage and it's on the motor so I'm concerned about the bearings that being used as alternative current path which is the fast way to kill bearings.

First thing I'll want to check the ckp for the voltage. I'd like to see where it's at (maybe it have bad diode or something) and see if it's what make the high voltage. Ckp have some magnetic field to work. Same concept- a/c compressor clutch usually have diodes to prevent voltage from build up when it's not in use. Maybe same thing used in ckp? Just a idea.

 

Automatic transmision and all of the gauges are working fine. I noticed this arc while down in mexico last week and drove home with no problems approx. 300 miles. A couple of times I have started the truck and the arc has not been occuring but the next day it is doing it again. I and taking it in to my mechanic today and will let you guys know what he finds.

 

i just had this problem. it was a slipping belt causing static electricity.....weird

 

I can hear a click noise also coming from my 97 5 speed. it goes click click click then pause for a few seconds then repeats. the sound changes with engine RPM. any ideas? Someone said it might be a bad lifter but correct me if I'm wrong but the 12 valves are all solid lifters not hydraulic right?
My tach also jumps around sometimes and drops to zero....

 

Check your damper for rubber sticking out the back and rubbing the timing cover as it goes by. That turns the damper into a large static generator, which then builds voltage up on the outer ring of the damper until it arcs over someplace.

 

05 with belt and pulley problem

my truck (05) had a code for ckp with all the symptoms associated. replaced and still the same. then the idler pulley and belt broke. this alleviated the symptoms but the ckp code is still thrown. i haven't had time to replace the belt and pulley yet. is it possible there was enough static electricity to damage the ckp sensor?

 

Looks like TallCan never posted what the Mechanic found. I just noticed this happening to my 01 the past few days.

How can you check the back side of the dampener? It's so close to the front of the engine to begin with I can't see how I can determine if that's the cause or not.

 

If rubber is pooching out the back of the damper from the rubber ring, you should either replace the damper or take a razor blade and slice the rubber off. I'd highly advise replacing the damper.

 

My mechanic replaced the napa belt I was using with a factory type Dayco belt and this solved the problem. He went through everything else and was amazed that the belt was causing the arcing.

 

That's an interesting result. I can see how it could work that way, especially if the napa belt was slipping just a tiny bit, maybe each time a cylinder fires and the torque pulse reaches the damper. That could provide the friction needed to build a static charge on the outer part of the damper.

 

my 99 24valve is doing this, i'm going to try changing the belt and see what that does, ill post the results just to give an idea if it was really the belt or just luck that it has stopped on other vehiclesarty018: