Do I need to use the heat shields that cover the spark plug boots down at the head? Mine only came with 3 on the front of my 85 2.8 and none on the rear. I've replaced the spark plugs but my gut tells me the shields are there for a reason, heat or static noise or something!

Engines run fine without them. Perhaps the design engineers were worried about heat distorting the spark plug boot, but those metal covers attract a lot of heat too.

I have done a lights out test with them on and have seen allot of leakage traveling to the head.
I think the boots for the spark plug sets are far better now then what came out in the 80's.
These shields become degraded over time and lose allot of their insulating properties.
On top of that the material that’s inside of them cracks and in some cases has fallen out further aiding conductivity.
My 2 cents would be to remove them.

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I've wondered the same thing. My 1999 Grand Prix GTP had them too. But the GP shields also had a small spring inside of them that looks like it grounded out on the block. I've always assumed it was for heat.

I have new spark plug wires so I'll leave them off.

TFS sells them if you change your mind.

They don't fit all wire sets. I got Accel 8.8mm wires. The boots won't fit over the plug and inside the shields at the same time.

Not a huge issue for most of us that keep the car in the garage, but the heat shields also prevent debris from falling in and around the spark plugs.

I took mine out for a season when the car sat outside, and there was so much rust around the plugs that they're basically sized in there now (and I had just rebuilt the engine a few years before)


I personally prefer to use them... what is the material that goes between the boot and the shield and where / how can we order it to replace it?