I think I found the miss

chevrolet
silverado1500

#1

2007 Chevrolet Silverado Classic 1500, 5.3 engine, 210k miles. I thought I was feeling a slight miss in the engine. When I stopped for gas, I opened the hood to check the oil and noticed this, the # 5 spark plug wire was up against the bolt on the steering column. I rotated the wire at the boot 180 degrees to get it off the bolt. The insulation is definitely worn down where it touched. No CEL or codes.


#2

Good work finding it. It feels good to find a clear reason for a problem and fixing it.


#3

Definitely good diagnostic work there. I had a similar problem on my 45+ year old Ford truck last summer. The problem was the transmission shift lever was hitting the wire, thinning the insulation over time. I just wrapped the bad spot in several layers of Scotch 33+ electrical tape, which fixed the slight miss straight away.


#4

Yeah I had that happen too but touching a different part.


#5

yeah, good work. But either replace the wire or wrap it with good electrical tape.


#6

Nice logical work, starting with the basics, with an eye for detail. Gus Wilson hires guys like you! Thanks for reporting your results.


#7

If the spark was arcing to the steering column then you really need to consider the spark plug condition.

An aged plug or one with a large plug gap can cause an arc where there might normally not be one.


#8

That’s a good point but it appears the constant abrasion from the rotating steering shaft bolt wore away some of the insulation…


#9

Agree, since the truck is new to me, I plan on doing all maintenance items since it didn’t come with a maintenance history.


#10

Only the outermost part of the jacket is worn. I was thinking of just replacing the wire or wires when I do the plugs but that alone won’t solve the problem. I have some loom jacket that is just slightly larger than the wire and am thinking of getting a tube of RTV silicone. I’ll wrap a section of the loom, about 4" in the area abraided and fill the space between the wire and the loom jacket with the RTV. I can hold it in a straight line for awhile, or put a temp brace on it and when it cures, the wire should stay well away from the steering column then. I’ll post a pic when I get it done.


#11

We had a technician wrap one plug wire with electrical tape, the miss fire driving home turned onto being down a cylinder the next time the car was started, 3 out of 4 cylinders on a 1990 Mazda protoge doesn’t sound that great
We got a new set of wires for free the next day.