dontherogue

Hi all, we've had an early spring and so I want to proceed with changing the spark plugs on my '99 4.2l. It has 160,000 kilometers on it (99,400 miles) and so the plugs and wires could be original; I won't know until I pull the first plug. I believe it is recommended to 'twist and pull' on the boots to avoid damaging anything and different folks have different approaches to that. I know that you can buy special boot pliers for the job, other posters say to use needle nose pliers, regular pliers, curved needle nose pliers. Some sites just say 'pull the old boots off'. Whatever approach I take, I will use plastic handled pliers and wear gloves, but given how long those boots and plugs may have been sitting undisturbed, I want to proceed carefully. What do you guys recommend?

16IngotFX4

Meh, don't over think it.

Normally you can just pull them off. If they are stuck then you'll need to twist it. Just be cautious. Given the age, probably best to just twist it anyway. All you're trying to do is break the seal.

If the boot comes off -oh well. Then you'll have to get creative to find a way to pull the connection apart to the plug. Plies and patience probably.

I don't think you need special pliers. I'm sure they are helpful but I've never used any. Then again, most of my vehicles had relatively easy access to the plugs. And my recent vehicles were COP. I had a shop change my 03 plugs. I didn't change them on my 08 GM and I just changed plugs in my 2016 3.5 a few months ago.

I don't know why you would you mention using plastic handled pliers and will wear gloves. Probably no need to explain -I just can't figure out where you're going with that suggestion.


Don't take this the wrong way, please.
I don't like to encourage somebody NOT to learn things, but if you are having concerns with how to remove plug boots -this job may be best for a shop. You mention not wanting to damage a boot but what is going to happen if a spark plug breaks?
You should use a universal joint attached to your spark plug socket too to help reducing risk of breaking the plug from operator error but you can't control seized threads and snapping the plug.

dontherogue

Thanks for the input. I have changed plugs on other vehicles many a time, but on this one I'm being super careful because of the possibility that those plugs and wires have been sitting there for almost 22 years (vehicles I worked on as a younger man didn't have platinum plugs and so had to be replace more frequently). The thing is, I won't know if the plugs need changing until I determine if they're original or not. The truck runs fine but at 100k the manual says to change them. Once I've got the first one out I'll know, and it may be that I can just put it back and snap the boot back on. That's why I'm being so cautious - don't want to damage a boot or snap a plug and then find out they're not original and don't need to be replaced. Your advice about the u joint is appreciated as well - it makes good sense.

BareBonesXL

Twist and pull on the boot works. They're just "old school" plugs, boots, and wires, same as the last 3 or 4 decades, nothing fancy.

Don't forget to scrape around down in the well around the plugs and blow them out well before removing. Even though the plugs are on the side, the wells still collect dust, dirt, leaves, bugs. Overall, it's just like changing plugs on an old Chevy engine.

As far as the 100,000 miles, my plugs were obviously worn at 75,000 miles (I posted a thing about it). The gap was extra big from the electrodes wearing down.

16IngotFX4

Ahh, good to know.

I hate to sound offensive with such suggestions but sometimes people get in over their head when decide they want to do their own maintenance without experience!

Good tips above too about cleaning the plug well. Once you get the plug free, work it back and forth a little if it feels corroded too.

I had the plugs changed in my 5.3 Triton at right about 100,000 for good faith. I didn't check the gap but I saw them on the bench at the shop and they looked impressively good (without knowing the gap). It ran the same driving home as it did driving in too.

Good luck!

dontherogue

Hi again all, I wanted to update my spark plug replacement. I carefully removed one plug (well I thought I was being careful but it turned out my brand new spark plug socket wasn't all the way on and I stripped it pretty good but still managed to get it out). Saw right away these were the original plugs that have been in the truck since 1999. Ordered a new set of Motorcraft plugs and United Automotive wires (lifetime warranty and much better price) and they arrived late last week. The other 5 plugs were easier to remove because I made sure the plug socket was fully seated by tapping it in with a hammer. The job was rated at an hour by a garage I sometimes use, and it took me about 3 and a half (well I said I was being careful). The truck was running fine before the job but looking at the plugs, I am surprised at that. Some of the gaps are close .080 instead of .054. To anyone who is doing this same job, I'd say to check the gap on the new plugs. They are supposed to be at .054 but all 6 were more like .044. So I had to expand them a touch. Anyway, thanks to all who chimed in with advice. As you can see below, those original plugs needed to come out of there. Truck has 160,520 kms, on it, or 99,750 miles.