My 2004 silverado has 116000on the clock and I know it needs new plugs, but I am scared that all that time the plugs have had time to seize in the aluminum heads.
I am afraid that one or more will tear out the threads resulting in pulling the heads to repair. Do I really need to worry or am I over thinking?
Is there anything I can do to prevent this or do I just go for broke and deal with whatever happens?

Can’t tell unless someone attempts to remove the plugs.


You will be fine, if you had a Ford that would be a problem.

Why if it was a Ford? What is the difference?

Be sure it’s dead cold when you do it. If a plug won’t turn don’t force it. Even at that mileage I doubt you will have a problem


Don’t worry. We have tons of gm trucks just like yours in our fleet, and we haven’t really encountered any problems with broken or stuck plugs

Now a Ford would be a different story. Some of the 2V Tritons like to blow the plugs out, taking the female threads and the coil with them. Some of the 3V Tritons have mile-long plugs that often break during removal, unless you have the OTC 6918 removal tool. And if one does break, you’ll more than likely be using a Lisle special tool to extract them.

Moving on . . .

A bit of advice . . . Buy a new set of spark plug wires. They have a particular tendency to break when removing them on your engine. I’m assuming you have either the 5.3 V8 or the 6.0 V8

A colleague . . . non-mechanic . . . asked me for advice before doing the plugs on his 2004 Sierra. I told him to have a fresh wire set on hand, before removing the plugs. He didn’t take my advice. A few days later, he dropped by and said he didn’t have problems replacing the plugs, but after he started the engine, the check engine light came on and there was a clicking noise from one single wire

I gave the cheapskate a good used spark plug wire and sent him on his way. A few days later, he again dropped by and said the clicking had stopped as soon as he replaced that wire.

Hopefully, I was able to answer your questions

Ford has a issue with their spark plug design on the triton motors. You need special tools most of the time due to the plugs breaking in the head.

One advantage you have with your 2004 Silverado is that the engine sits longitudinally and not transversely. This makes the plugs easier to service.


“Ford has a issue with their spark plug design on the triton motors.”

That’s wording it nicely

I would have said “Ford s . . . . . . d the pooch with their spark plug design on the triton motors.”

Have you tried out the OTC 6918 tool yet?