Strange electric shock on engine...
08-18-2010, 06:58 PM
#1
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Strange electric shock on engine...
Alright guys here's a wierd one.
While my truck is running there is a small jump of electricity goin from the bottom wheel on the front of my engine, jumping to the front lip of the oil pan. Across the about 1 inch gap. Almost like a spark but you can see it connecting from the wheel to the pan. http://www.google.com/imgres?imgurl=...w=1259&bih=736 The bottom rusted wheel in this pic.
Its like clock work. About every 10 seconds, POP. You can hear it over my engine running!
I just noticed it a few days ago, PRETTY sure it hasnt always done it. The local diesel shop And dealership both said.. Whoa, ive never seen that before.
I cleaned the passenger side battery ground that bolts to the engine but not the driver side one yet. Belts seem clear and not touching anything unusual (thought it might be rubbing and building friction then discharging with the shock).
Any one have and ideas??? Im worried it could start a fire of fry something!
While my truck is running there is a small jump of electricity goin from the bottom wheel on the front of my engine, jumping to the front lip of the oil pan. Across the about 1 inch gap. Almost like a spark but you can see it connecting from the wheel to the pan. http://www.google.com/imgres?imgurl=...w=1259&bih=736 The bottom rusted wheel in this pic.
Its like clock work. About every 10 seconds, POP. You can hear it over my engine running!
I just noticed it a few days ago, PRETTY sure it hasnt always done it. The local diesel shop And dealership both said.. Whoa, ive never seen that before.
I cleaned the passenger side battery ground that bolts to the engine but not the driver side one yet. Belts seem clear and not touching anything unusual (thought it might be rubbing and building friction then discharging with the shock).
Any one have and ideas??? Im worried it could start a fire of fry something!
08-20-2010, 08:58 AM
#4
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Actually sounds like a capacitance type of discharge. Amps build up and then, pop, arc across the engine. Can you put a voltage meter on it to see which side is ground and which is hot? I would guess it's a bad ground from the engine to the frame....
08-20-2010, 09:04 AM
#5
I wish I was as fine, as those who work the pipeline!
That's what I was thinking. Get some new 12 Ga wire and ground your engine to the frame. If the 'spark' goes away, now you know there is a bad ground somewhere. The volt meter will tell you which direction. You will also be able to see how much build up before it releases. If the spark is arcing across a 1" space, that is significant. Might want to check your starter connections as well.
08-20-2010, 08:02 PM
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Or Should I actually bolt up new wire somewhere? If so, Where would be good? Just anywhere that would put clean engine to clean frame?
08-20-2010, 08:37 PM
#7
I wish I was as fine, as those who work the pipeline!
Ya hold it by hand, If you get a spark through the insulation on the wire you have BIG issues!!!!
On edit: A set of jumper cables would work just fine. Put one on the lifting eye and one on the frame somewhere.
You could also use the clamp of the jumper cable to hold one probe of your volt meter to the engine too.
On edit: A set of jumper cables would work just fine. Put one on the lifting eye and one on the frame somewhere.
You could also use the clamp of the jumper cable to hold one probe of your volt meter to the engine too.
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08-21-2010, 12:34 PM
#8
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Are you sure its not the a/c compressor cycling??? The balancer is isolated. hub-rubber-belt pulley-belt. The hub is isolated and the belt should be an non-conductive isolator. A bad balancer could be slipping and the belt pulley could at times hit the cover or bolt head and create a spark. There is nothing there that should create energy. Only thing close is the a/c compressor which could spark when the plates are energized. Plus it cycles in a timely manner as you describe.
08-22-2010, 09:54 PM
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I can tell that the "spark" is for not being caused from two things hitting.
Its definantly an arc going on. It like if you ran across carpet in socks, then slowely reached out to someone and you see the electricity jump from you to them before you even touch em.
Today I un bolted both battery grounds to the block and cleaned it all off very very well.
Went to the store and looked under then and it wasnt doin it.
BUT Its been random times when its done it before, its not constant everytime the truck is running, just most of the time.
Now that I cleaned those, Ill check for it alot and next step will be tryin to ground it out if it happens again. Ill keep you guys posted.
Thanks for the replies I really appreciate it all.
Its definantly an arc going on. It like if you ran across carpet in socks, then slowely reached out to someone and you see the electricity jump from you to them before you even touch em.
Today I un bolted both battery grounds to the block and cleaned it all off very very well.
Went to the store and looked under then and it wasnt doin it.
BUT Its been random times when its done it before, its not constant everytime the truck is running, just most of the time.
Now that I cleaned those, Ill check for it alot and next step will be tryin to ground it out if it happens again. Ill keep you guys posted.
Thanks for the replies I really appreciate it all.
08-25-2010, 09:05 AM
#12
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Yeah, what I meant was try to figure out which side is hot and which is the ground at that particular point. I would put a voltage meter across the oil pan to the frame and see if you get a reading. If you do, then you know your engine is not grounded properly. There are a couple of grounding wires to the engine to check for continuity, too. Does your alternator wiring look okay? Is your air conditioner on when the arcing happens? Are there any codes at all? I would also watch the School House Rock "Electricity" video a few times. Taught me all I know....
08-25-2010, 01:24 PM
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Sounds like Static electricity buildup...
Dry, dry desert air and the outer "wheel" of the harmonic balancer is mounted on rubber between the outside "wheel" and the inner hub on the crankshaft.
The very close-by serp belt is likely transfering static electricity to the balancer mass as it rotates.
Van-de-graff generator works the same..
Try this... While it is running and sparking, lightly squirt/mist some water onto the belt/pulley/balancer area with a squirt bottle...
See if that doesn't stop/slow the "sparking" until the moisture evaporates again...
If that is what is going on, you may be able to stop the buildup by taking a small piece of aluminum duct tape and place it across the insulated rubber part of the harmonic balancer. That way the electrons will bleed off through the crankshaft and not build up until they reach flashover voltage.
Most belts have some anti-static compounding in the rubber to minimize this problem. You may have to switch serp belts to get rid of it.
I had a 1/3Hp electric motor doing that on my home HVAC blower motor.
The V-belt would generate the static electric current and deposit it on the motor pulley.
The tiny grounding braid across the rubber motor mounts had broken from fatigue and the now ungrounded shell of the motor was building up a serious amount of static electricity! The voltage would build until it would arc over to the grounded motor frame with an audible "POP...POP...POP!"
This was detectable in all AM radios in the house too!
Dry, dry desert air and the outer "wheel" of the harmonic balancer is mounted on rubber between the outside "wheel" and the inner hub on the crankshaft.
The very close-by serp belt is likely transfering static electricity to the balancer mass as it rotates.
Van-de-graff generator works the same..
Try this... While it is running and sparking, lightly squirt/mist some water onto the belt/pulley/balancer area with a squirt bottle...
See if that doesn't stop/slow the "sparking" until the moisture evaporates again...
If that is what is going on, you may be able to stop the buildup by taking a small piece of aluminum duct tape and place it across the insulated rubber part of the harmonic balancer. That way the electrons will bleed off through the crankshaft and not build up until they reach flashover voltage.
Most belts have some anti-static compounding in the rubber to minimize this problem. You may have to switch serp belts to get rid of it.
I had a 1/3Hp electric motor doing that on my home HVAC blower motor.
The V-belt would generate the static electric current and deposit it on the motor pulley.
The tiny grounding braid across the rubber motor mounts had broken from fatigue and the now ungrounded shell of the motor was building up a serious amount of static electricity! The voltage would build until it would arc over to the grounded motor frame with an audible "POP...POP...POP!"
This was detectable in all AM radios in the house too!