what does the spring do on plug shield?
 

I have seen pictures of spark plug wires with the heat shield. There appears to be a spring at the end of the shield. What is the purpose of the spring? Does it help hold the wire on the plug? And does the spring make it more difficult to pull the wire off the plug?

Thanks,

Trebor

PS - I have a 2006 and it has the shields. At 46,000 miles, I am just looking ahead to changing them someday.

OK - since I have had almost 40 views and no responses, maybe a pic is in order. Here is a guy from the sales forum trying to sell his plug wires. He posted a pic of the plug wires so you can see what I am talking about. Note the spring at the bottom of the shields.

https://www.corvetteforum.com/forums...s-7-total.html

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The plug wires are clearanced by the spark plug terminal, not the heat shield, which is necessarily shorter. I think the spring just takes up the gap and prevents the shield rattling against the plug body.

Thanks for taking a shot at this. The spring must slide over the plug. I would think that spring would make it harder to click the wire boot onto the plug ; And conversely, make the boot harder to pull off the plug when changing the plugs. I'm not sure if I will re-use them.

Trebor

I would certainly re-use them. A tip I picked up when changing the plugs at 100k miles on my Yukon where it is difficult to get enough mechanical advantage to remove the plug wire/boot from the plug, use a shoelace. Tie a shoelace onto the boot so you can get your hands back for better mechanical advantage to remove the boot if it is stuck to the plug.

The real reason the spring is there is for EMC concerns. The spring guarantees that the shield is grounded to the block.

i know you called it a heat shield and although it might act like a heat shield , I was told it’s also needed for EMC concerns.