Changing Spark Plugs and Wires.

[Blown93SSEi]

Swapping the current ones out for NAPA belden wires and NGK Iridium plugs. I've never changed them before. Anyone have any advice to make sure I do it right and what to expect when doing this?

[PRD2BDF]

Make sure your ratchet is set to "lefty loosey" and not "righty tighty" before you even approach the car.

I was upside down trying to remove the rear bank and I had it set on righty-tighty and I wasn't thinking. Ending up snapping the spark plug and had to remove the head to get it out.

Lesson learned.

Oh and have the motor slightly warm but not hot so that the metal expands.

[LeSabre in Buffalo]

Get some padded mechanic's gloves and nitrile globes. If those spark plug wires are original, they will give you a dickens of a time. When they come off, your hands will fly into anything that happens to be in the way. That's as painful as it sounds.

Get some anti-seize and dielectric grease, also. Put the anti-seize onto the threads of the plugs and the dielectric grease onto the part of the spark plug that resides in the boot. This will make any future replacement much easier. Just a light amount is sufficient.

To get:
Gloves:
Mechanic's
Nitrile

Chemicals:
Anti-seize
Dielectric (tuneup) grease

Harbor Freight also sells a 5" long spark plug socket that works very well on our engines, especially for the rear bank.

Some folks find that removing the strut tower brace helps with getting the old plug wires off.

Good luck!

[00Beast]

Also make sure you route the wires out of the way of the O2 sensor wiring and any heat sources. I had some cheap wire separators that worked excellent when I did mine last time.

[99BonnevilleSE]

I just did this yesterday. And it was quite the pain. Luckily I had the lift at my school and was able to get the back 3 plugs. But as somebody said gloves are nice. My hands have cuts EVERYWHERE from doing this job and them smacking into things.

[94SilverSSEi]

Wasn't it the iridium plugs that you don't want to put in a supercharged car?

Or I am thinking of platinum or something?

I know there was a certain type of spark plug that is not good for the supercharged cars.

[LeSabre in Buffalo]

IIRC it's platinum, specifically Bosch, that don't play nicely with an L67.

I have NGK iridium plugs in my Buick, and they work nicely. It's also on an L36 application, not an L67.

[Bonnefied_GM]

Nothing wrong with Delcos either. I've used Delcos (or Autolites even) without a hitch so far in all my cars.

[gonzo4191]

jake no iridium in an L67!

if you need help, i could always come out or you can come here!

[human]

Having done this for the first time last fall, I discovered three things that really helped:

1. Make sure you've got a three-inch extension for your ratchet. You'll need it on the rear bank of plugs.

2. Take out the support bar that runs across the engine bay between the strut towers. It will give you a little better access.

3. Remove and replace the wires one at a time so you maintain the correct firing order. It may be tempting to yank out all of the old wires at once and then start replacing them, but that increases the risk of connecting a plug to the wrong coil, causing it to fire out of sequence.

Other than that, it's pretty simple and straightforward. It took me a little over two hours, including running to a nearby Harbor Freight midway through the project to get the extension. The cheapest way to get it was to buy a 40-piece socket set for a whopping $3.98 on sale.

I used basic Delco copper cores and the car has purred like a kitten ever since.

[Blown93SSEi]

jake no iridium in an L67!

Can anyone clarify. I thought iridiums were preferred over platinums?

[SUSPECT 0]

Iridium is more corrosive resistant than platinum, iridium is actually the most corrosive resistant metal but aside from that, I have heard that the small electrodes on the iridium plugs don't do well in forced induction engines (the small iridium tips have a better chance of breaking off into the cylinder do to the added pressure)

EDIT

[1oldman]

Having done this for the first time last fall, I discovered three things that really helped:

1. Make sure you've got a three-inch extension for your ratchet. You'll need it on the rear bank of plugs.

2. Take out the support bar that runs across the engine bay between the strut towers. It will give you a little better access.

3. Remove and replace the wires one at a time so you maintain the correct firing order. It may be tempting to yank out all of the old wires at once and then start replacing them, but that increases the risk of connecting a plug to the wrong coil, causing it to fire out of sequence.

Other than that, it's pretty simple and straightforward. It took me a little over two hours, including running to a nearby Harbor Freight midway through the project to get the extension. The cheapest way to get it was to buy a 40-piece socket set for a whopping $3.98 on sale.

I used basic Delco copper cores and the car has purred like a kitten ever since.

I would add to that, anti-seize to the plugs. Use sparingly, and a swivel head ratchet. It's almost impossible for me to change the rear plugs even with the strut tower brace removed and the 3" extension and no swivel head ratchet. I think the swivel head ratchet is about $20 at Sears and well worth the investment.

http://www.craftsman.com/shc/s/p_10155_ ... ockType=L1

Well, just looked. They're going for about $33 now. Either they went up or I got it on sale. - BC

[LeSabre in Buffalo]

This has helped me quite a bit changing spark plugs on my Buick:
http://www.harborfreight.com/automotive ... 91705.html



Either a 19mm wrench or a 3/8" socket fit into the end. They've raised prices. It was $5 when I got mine.

[00Beast]

Clarification: Iridium is fine, it comes OE in all L67's. Platinum is to be avoided like the plague. I highly recommend copper though, especially if you plan on any mods at all. If you already have the iridiums, they'll be fine to put in. Just don't try gapping them.

[phils97bonn]

I need to change plugs soon and I see quite a bit of gunk/dirt around the spark plug holes. Anybody got any tips on how to clean these up? I've never seen this even mentioned on this board so I'm wondering if most folks don't worry about it and just hope for the best.

[myfirstbonnie]

First of all, please do not dig up year old threads. Start a new one and link to this one.

I suggest you get a good degreaser and clean the engine a couple of times and get a brush to scrub around the plugs before removing them. Then clean it over a period of time and it will stay clean. Then look for the oil leaks which are usually the valve cover gaskets which are not a hard thing to replace.

[phils97bonn]

First of all, please do not dig up year old threads. Start a new one and link to this one.

Ok, I guess I don't know the protocol. I thought starting a new thread was to be avoided.

Thanks for the cleanup advice though.