Balancer throwing sparks

[Toby Cashion]

My truck is throwing a spark from the balancer to the timing case. Any ideas? It happens about every 5 seconds. :doh:

 

[Bullrack]

Heard of that before but can't remember what the problem was. Maybe a short through the crank position sensor wires or something. Steven.

 

[24VChevy]

Too much end play in the crank?

 

[Toby Cashion]

I pulled the crank sensor off... still doing it
Wired the sos up and turned the key off, still doing it.
Can DC throw a spark or is it AC or WTF?
Looks like someone is welding under my truck at night time

 

[GANDJDIESEL]

THATS COOL any video
If its on the 12valve it can be the crank sensor. It also can be what Malcom said.
I seen it once on truck with bad grounds to the batteries.

 

[72chevy]

Static build up?

 

[Toby Cashion]

I will check the grounds tomorrow, i know there covered in oil so im gunna bet thats what it is. Thanks for the fast replys guys

 

[Toby Cashion]

End play in the crank? like the thrust bearing is wore out? Explain please

 

[gunracer1]

The crank shaft will move forward and backward. It is not unheard off. Sometimes a transmission job gone bad will put a pressure on the back of the crank and wear the bearing surface down and let the crank walk back and forth.

 

[zstroken]

Static build up?

I can't see it being static as the balancer is conductive, as sell as the other stuff around it and the film of oil wouldn't allow much build up.

 

[toms73novass]

The outer part of the balancer is not grounded to the rest of the engine due to the rubber isolator between the hub and the outer ring.

They only way that you can develop a visible spark to jump a gap is to have high voltage (will not happen in any part of our electrical system, it's not a gasser) the only way that this will happen is by static charge buildup. You can develop 1000's of volts in this way and that WILL give you a spark that will jump a gap.

The two issues that I have seen pop up several times is

a) There is part of the rubber on the balancer that has come loose and is hanging out and rubbing on the backside as it spins causing a static buildup.

b) The fan belt is slipping causing the static build up. (Easy way to find out is to remove belt and run for a short bit, since you see the spark every 5 seconds, if no spark you know its the belt)

 

[zstroken]

Guess I was thinking of my fluid dampr as I recall it was metal all the way around.

 

[sdime89]

i seen on a buddy of mines truck do the same thing ended up being a timing cover bolt backed out and fell down and was stuck on the inside of the dampner only did it at high rpms

 

[Toby Cashion]

Powerwashed motor, redid all the grounds.
AC started working again after months and no sparks, thanks guys