Changing the spark plugs.

[Red Byrd]

My 1995 Thunderbird LX is coming up on 90,000 miles. The book says this is the time to change the spark plugs as part of the regular maintenance process. I am somewhat mechanically inclined, but I haven't done something like this before. My question is, can I and should I do this myself or go to a repair place/dealer?

[NDGator]

My mechanical experiences include changing oil, brakes pad/caliper/rotors, water pumps, radiators, starter, alternator, belts & spark plugs.

That being said, I think the water pump on my 88 Chevy Truck was easier than a driving light on my SRT Magnum so it is all relative.

If those are things you have done, then you are probably fine.

Are all 8 cylinders accessible. Decide this before you start. I had to change the last back three plugs blind on my Fiero due to the engine arrangement in a tight space.

You may want to loosen the old ones with a WD40 (or whatever the TF experts recommend) nothing like braking off a plug in the block. Buy a gap wheel for a buck from the parts store. They are usually on the counter like candy when you check out.

[Marc P. Gregoire]

I believe your motor has aluminum heads so be careful to not cross thread the plugs and tear up your cylinder heads. Make sure to use anti-seize compound when installing them as well.

Make sure you can get at all of the plugs and if you can't, find out what tools you would need to get at them. Make sure that nothing ridiculous has to occur like on my friend's car where you have to pull the intake manifold to change the plugs. On some newer vehicles it is an 8 or more hour job.

Make sure to get the right plugs because they will greatly affect your running. Look up what is the gap spec, etc. for them online and see if there is any info about a particularly good running plug setup for them. Change your plug wires and check your other ignition parts while you are at it.

The T-Bird is a rear drive car with a fairly large engine compartment so it might not be that bad of job.

[KevMcNJ]

make sure they are still gapped correctly when they are tightened down

this may sound like a "no duh" comment at first, but if youre trying to thread it in by braille, its very easy to hit the elctrode on something waaaay in the back when youre trying to get it started and it will sometimes change the plug gap w/o you even realizing it. might even close the gap completely

You will not know it until you start it up and the car wont run correctly

It will run, but you will know some thing aint quite right.

then you get to spend the rest of your wknd troubleshooting

[TM1511]

I had a friend that was a hack mechanic and enjoyed changing plugs to try different ones out for "performance" He had a 4 cyl S10 pickup which didn't have much performance anyway. He went from splitfire plugs (misfired badly) to another set and then another. A few months later, he was getting on the highway and the thing started running very poorly. He pulled off and under the hood found one of his plugs dangling from the plug wire. He ended up replacing the cylinder head. He didn't bother using anti-sieze.

[NDGator]

make sure they are still gapped correctly when they are tightened down

this may sound like a "no duh" comment at first, but if youre trying to thread it in by braille, its very easy to hit the elctrode on something waaaay in the back when youre trying to get it started and it will sometimes change the plug gap w/o you even realizing it. might even close the gap completely

You will not know it until you start it up and the car wont run correctly

It will run, but you will know some thing aint quite right.

then you get to spend the rest of your wknd troubleshooting

Yepper did that a couple different times on the front three plugs on the Fiero. Not a very good sound and even worse knowing the you were going to burn your arm getting out and back in after the engine a run even for a few seconds.

[Red Byrd]

make sure they are still gapped correctly when they are tightened down

this may sound like a "no duh" comment at first, but if youre trying to thread it in by braille, its very easy to hit the elctrode on something waaaay in the back when youre trying to get it started and it will sometimes change the plug gap w/o you even realizing it. might even close the gap completely

You will not know it until you start it up and the car wont run correctly

It will run, but you will know some thing aint quite right.

then you get to spend the rest of your wknd troubleshooting

At the risk of exposing my (lack of) mechanical prowess, how exactly would you check it once they are tightened down?

Thanks for all the replys so far!

[KevMcNJ]

At the risk of exposing my (lack of) mechanical prowess, how exactly would you check it once they are tightened down?

you dont and you cant. If you want to check it you have to remove it. If you remove it you have to re-install it

Kinda like checking a bullet by firing the round off.

thats why you do your best not to hit the electrode on anything when trying to wiggle it in place.

If you are able to, how about a pic or two of the engine compartment of the car in question. Im guessing if there were pics, we could tell you if its go or no go for a shade tree mechanic

[stnkypete]

Once you have decided, change one plug at a time.
remove plug
Install new plug.
Change plug wire
Connect plug wire to spark plug
repeat

If you pull all the wires, it is unlikely you will remember which one goes where.

[cheeseczar]

Once finished you will be qualified to change a water pump on a GM quad-four...

[dog-ring]

Once finished you will be qualified to change a water pump on a GM quad-four...

[Marc P. Gregoire]

Once finished you will be qualified to change a water pump on a GM quad-four...

"What do you mean 11 hours of labour to replace a $31 part? I bought a Cavalier, not a VW!"

[Red Byrd]

If you are able to, how about a pic or two of the engine compartment of the car in question. Im guessing if there were pics, we could tell you if its go or no go for a shade tree mechanic

Asketh and thou shalt recieve

The car

This stick used to be a fishing rod

Closer up

Even closer up

Heres a money shot

Wonder who put the oil in

Here's a pic for my street cred (old vehicle)

[Indy500fanatic]

I had a friend that was a hack mechanic and enjoyed changing plugs to try different ones out for "performance" He had a 4 cyl S10 pickup which didn't have much performance anyway. He went from splitfire plugs (misfired badly) to another set and then another. A few months later, he was getting on the highway and the thing started running very poorly. He pulled off and under the hood found one of his plugs dangling from the plug wire. He ended up replacing the cylinder head. He didn't bother using anti-sieze.

I've never anti seized a spark plug and have never had any issues changing them or causing any damage...
Sounds to me like the hack mechanic changed plugs when the engine was warm/hot. Very easy to pull the threads on an aluminum head when doing it that way...
( I just put a set of bosch platinums in my wifes honda accord last night)

[dirtfan]

A Use anti-sieze
B Thread them all the way in by hand BEFORE using the wrench
C If you have to, use a piece of fuel tubing as a U-joint for the hard to get to ones.
I have aluminum Offenhauser heads on my flattie V8-60, I treat them like they were gold.