oldblues

hi
well here is one for ya all!

foolin around the truck today , just bored i guess .

had the engine running and heard a faint snap every once in a wile ???

so sound comming from front of engine area ok .

looked down from driverside at crank balancer/pulley while running .

HOLLEY COW !
there is a brite blue spark about every 20 revolutions jumping from the edge of the pulley to the timing cover !!!!!!!!!!

spark lookes like what you see when you pull a plug wire off a gasser and hold it app 1/2 in from plug terminal !

what is causing this ????

has anyone ever heard of this or had it happen ?

xzaq103

UM UM UH uh um WHAT????

Chris

SoTexRattler

Static Electricity!

An engine's serpentine or V-belt can act just like the rubber charging belt in a Van De Graff high voltage generator...
It generates a static charge the best when the humidity gets really low.

I had our HVAC air handler do this many years ago. It was driving my Ham Radio receiver crazy with an absolutely awful static. I traced it down to the broken flexible braided ground wire molded into the rubber mounting bushings on the motor's cradle mount. The motor's case was not formally grounded (220vac, no neutral) and when running, it built up a bunch of static electricity to arc over to the well grounded cradle frame from the static built-up from the V-belt.. Made a real ragged popping to a slow buzz depending on how dry the air was. Reattached another piece of wire from the case to the cradle and no more noise.
Not sure how you can stop this except replace the belt with one brand that has better anti-static characteristics.

All I can say is you must be in an awfully dry environment right now!


K.

plow

The only thing down ther that could throw an electrical spark is the ESS. Check the wires running to it and check the gap between it and the dampener with a brass feeler gauge, clearance should be 50 thous. Usually when theres a problem with the sensor the tach acts up.

Jim Lane

I am going with the Cummins powered Van De Graff generator.
I would think that kind of a discharge could wreak havoc with the electronics.

See if you can draw it off with the tip of your finger, if you can then it is defiantly an arc.

Valv

Are you asking him to put his finger on a running engine, near a spinning cooling fan, next to a rotating pulley and belt to touch a high voltage spark ?

XLR8R

Sure - why not?

Jim Lane

NO NO NO it was a joke, surely a Cummins owner would not stick their finger into a dangerous situation if I ask them to.
From the description of the discharge it sounds like static buildup.
Or you might have a bad ground wire on your Flux Capacitor causing it to Flux at random possibly causing an oily discharge at the vortex tube.
Van De Graff generators are neat to play with.

Just teasing.

XLR8R

Van de Graff Defibrillators are the heart of a good security system!

Jim Lane

The current of the Van De Graff is too low to do much harm other than to scare you.
When I worked for Conrac I got bit a few times from the 70kv flyback.

Van de Graff Defibrillators are the heart of a good security system!
Place the electrodes in the seat back so it can cet good access to the motor nerves.
Disclaimer..Just kidding.

XLR8R

That's the spirit!

92DuallyCTD

Hey that brings up a good point...Jim you guys gotta be careful what you say in jest, someone could well follow thru w/o thinking. That's just one of the hazards of being a guy with superior knowledge(such as yourself, wannadiesel, and all the great gurus of Dodge on this site!). Of course the greater number of readers would know immediately you really were joking...but it would only take one that didn't... But by all means don't let that stop you from dispensing all the great advice!

oldblues

hi
well i think not !

i am a voten fer the static thing as tach seems ta work o k .

humidity has been low here lately an a little cool .

thank you !