95 Spark Plug Replacement

[skifast]

Just finished replacing my plugs. It is a much easier job if you remove the coil pack and the cruise vacuum chamber, and the engine cover.

The cruise vacuum chamber is attached with two nuts. There is a vacuum line on the bottom that pulls off.

The coil pack is removed by:

Unplug 4 wire connectors, 2 on each side. The pairs have different plugs, so don't worry about mixing them up, you can't.

Unscrew two bolts on the front side of the coil pack mounting plate. The one on the passenger side has a grounding wire attached.

Unplug the spark plug wires from the coil packs. I mark them so I know where they go. I did not replace my wires.

There are two bolts on the back side of the mounting plate. If you climb up on top of the engine you can see them(a work light helps), or you can feel for them. Don't worry about undoing something else, they are the only two bolts you will find. The bolts are 10mm.

Lift the coil packs off and set aside.

Replace plugs and reassembly in reverse order.

It helps to have the right tools. I used two or three different size extensions, a universal joint, 3/8 and 1/2 inch rachets. The 1/2 to remove the rear plugs, they were tight and the extra bulk of the 1/2 rachet helped. Also a spark plug socket with a rubber insert that holds the plug in place is great to have.

I have bought a lot of tools at Harbor Freight, they are cheap and good quality.

Strut replacement is my next project.

[aarcuda]

thanks for the schooling. this is an upcoming project for me. we need a stickey on this

[BACK2LIFE]

i shop at harbor freight tools all the time! great place for value tools. i buy too much stuff when i go in there though!

[hollywooddippa]

It sounds as bad as changing the plugs on my '98 Camaro. I have to have three diffferent extentions and two uni-wiggles on each side. My plug socket has a 7/8's hex head for a wrench on the back and I have to use it to take off two of my plugs.

I find out tomorrow if I'm getting the '97 Aurora. Plugs and wires are two of the many things I'll be doing to it in the next week. Does it really hold 7 1/2 quarts of oil?!?

[skifast]

It is funny, I will go to HF for one thing and end up spend $50 on a bunch of stuff.

[NYsteve]

hollywooddippa said:

Does it really hold 7 1/2 quarts of oil?!?

Sure does! I hate having to buy a case of oil everytime i go to change it.

[peekamoose]

I just did the plugs/wires on my '98. I didn't have any problems with socket extensions...just the two or three in my toolbox. I was a little concerned with the torque specs, though; 11 ft.lbs. Seems pretty weak.
BTW, if you're doing the wires, be prepared to take your time. In my car, the original wires were numbered along their entire length. The new wires weren't, and it seems like every wire is a different length. I very carefully removed the rear harness, noted the routing, compared lengths of old w/new, then did the same with the front harness. The old gal loves the new plugs...never ran better.

[scottydl]

peekamoose, you are right on with the wire length issues... I had to switch a few around to make them all fit right. I finally completed the practically ALL DAY project of doing my 99's plugs and wires today. Glad I finally got it done though, and she ran smooth as silk during my test drive.

A few notes for my '99 that differs a little from skifast's '95. The mounting plate for my coil packs only had three screws (still 10mm), two on the front and one on the rear passenger side that was extremely difficult to see as described. The rear one had a ground attached on mine... one of the front ones too, but that was the aftermarket grounding mod that I added. Anyway removing the coil pack to kinda move it out of the way is a *must* for reaching the rear plugs and wires... I don't see any other way it could be done. I also had to momentarily remove some other small unidentified module that was completely blocking removal of the rear plug wire on the rear cylinder (#4 I think) on the far passenger side. Once the new plug and wire were in I reattached the single screw, no big deal.

What took me so long was not the removal and installation of the plugs & wires... that part was easy. I had problems with my spark plug socket getting stuck down in the holes. My wrench extension kept popping off the socket (once I had the new plug screwed in) and it took all varieties of wiggling, pleading, and fancy work with some needle nose pliers to get the socket out each time. Those mini battles probably took just as long as the rest of the job combined, so if you can figure out a way around that then it's no problem.

It really did help me reach the rear cylinders to sit up under the hood. That flat "shelf" over the radiator makes a pretty good seat. I slightly widened the gap on each of my new AC Delco plugs to .050" (they all came out of the box at about .040 to .045), and used a smidgen of anti-seize compound in the threads when installing them. Just don't be in a hurry when you do this and you won't get too frustrated.

P.S. Bought my AC Delco wires online, from PartsAmerica.com (Advance Auto). They're listed price is $128, but they price-matched Vandevere Oldsmobile's online quoted price of $96. That way I get the lifetime warranty and can return them to a local Advance store if I ever have problems.

[djstillman]

scottydl said:

peekamoose, you are right on with the wire length issues... I had to switch a few around to make them all fit right. I finally completed the practically ALL DAY project of doing my 99's plugs and wires today. Glad I finally got it done though, and she ran smooth as silk during my test drive.

A few notes for my '99 that differs a little from skifast's '95. The mounting plate for my coil packs only had three screws (still 10mm), two on the front and one on the rear passenger side that was extremely difficult to see as described. The rear one had a ground attached on mine... one of the front ones too, but that was the aftermarket grounding mod that I added. Anyway removing the coil pack to kinda move it out of the way is a *must* for reaching the rear plugs and wires... I don't see any other way it could be done. I also had to momentarily remove some other small unidentified module that was completely blocking removal of the rear plug wire on the rear cylinder (#4 I think) on the far passenger side. Once the new plug and wire were in I reattached the single screw, no big deal.

What took me so long was not the removal and installation of the plugs & wires... that part was easy. I had problems with my spark plug socket getting stuck down in the holes. My wrench extension kept popping off the socket (once I had the new plug screwed in) and it took all varieties of wiggling, pleading, and fancy work with some needle nose pliers to get the socket out each time. Those mini battles probably took just as long as the rest of the job combined, so if you can figure out a way around that then it's no problem.

It really did help me reach the rear cylinders to sit up under the hood. That flat "shelf" over the radiator makes a pretty good seat. I slightly widened the gap on each of my new AC Delco plugs to .050" (they all came out of the box at about .040 to .045), and used a smidgen of anti-seize compound in the threads when installing them. Just don't be in a hurry when you do this and you won't get too frustrated.

P.S. Bought my AC Delco wires online, from PartsAmerica.com (Advance Auto). They're listed price is $128, but they price-matched Vandevere Oldsmobile's online quoted price of $96. That way I get the lifetime warranty and can return them to a local Advance store if I ever have problems.

Very clever!!! And these are the same as the original wires, so there would not be a fussy car after replacement? Also, could you either post or PM details on how you got them to do the price match?

[scottydl]

djstillman said:

Very clever!!! And these are the same as the original wires, so there would not be a fussy car after replacement? Also, could you either post or PM details on how you got them to do the price match?

Yep, same OEM equipment. I know some people have had good luck with non-factory spark plug wires, but I didn't want to take any chances. I already had the AC Delco plugs from an eBay order some months ago.

Check out the PartsAmerica pricing policy for a complete description of their price match offer. I called the Customer Service 877 number and placed my order over the phone, so I could talk to an actual human being and know exactly how it would work. Prior to my purchase, I checked prices of the AC Delco wires at all the parts resources listed in this thread, and found Vandevere Olds to be the cheapest... and I don't even think they had wires listed online, I sent them an inquiry and got a price quote via e-mail response. From scrolling through the Advance Auto online catalog I saw that they listed a Lifetime Limited Warranty on their AC Delcos, and I know from previous experience that they are pretty liberal in handing out warranty replacement parts. So I called Advance, ordered, and gave the details about the lower price elsewhere. Guy said okay and noted it in my order, charged me full price up front but I got the difference refunded a couple days later. I don't know how they verified the lower price... they must have called/e-mailed Vandevere themselves or maybe just took my word for it. Also, Advance gives free shipping over $50 so I got that too. Had to pay sales tax, but it was more than worth it with all other monies I saved.

And the car is running GREAT, wife said she could definitely tell the difference driving to church this morning.

[aarcuda]

im going to try this with O'Reillys. they have a low price guarantee too!! thanks, I just filled out the online form of Vandervere Olds

[RapMastaC1]

How much would it cost to replace all the spark plugs and wires from them? How much time would it take on this car? I did it in auto class so I'm familiar on what to do, like finding the timing (does it say the timing on the alternator, or should I just mark the wire and when done with all the plugs replace the wire where it goes?

[austinator]

rapmastac1 said:

How much would it cost to replace all the spark plugs and wires from them? How much time would it take on this car? I did it in auto class so I'm familiar on what to do, like finding the timing (does it say the timing on the alternator, or should I just mark the wire and when done with all the plugs replace the wire where it goes?

Cost would be between 100-150 for wires and plugs. The firing order is on the coils themselves. Everything else is electronically controlled so as long as all the plugs are gapped properly you're fine. Normally a good idea to remove the coil pack to do the rear ones. Took me close to an hour.

Austin

[aurorabrain]

The problem with the socket getting stuck on the spark plugs can be avoided by purchasing an extension with a locking end on it. Craftsman has some decent cheap ones, and they're lifetime warranty.

[A-boy95]

I did my plugs just last week, i used NGK iridim IV plugs and acdelco wires.

i didi the whole job in about a hr. and it only cost me 133.76 thanks to my connections with oreilys from the college

[meddler]

I recently purchased some Bosch +2 Platnium plugs but then heard the AC Delco ones are better, should I exchange them?

[algonquin]

meddler said:

I recently purchased some Bosch +2 Platnium plugs but then heard the AC Delco ones are better, should I exchange them?

I have never been fond of all these so called miracle plugs. Dollar for dollar you best bet is to use the recommended GM plug. Especially if you have a fairly stock engine.

[scottydl]

algonquin said:

meddler said:

I recently purchased some Bosch +2 Platnium plugs but then heard the AC Delco ones are better, should I exchange them?

I have never been fond of all these so called miracle plugs. Dollar for dollar you best bet is to use the recommended GM plug. Especially if you have a fairly stock engine.

Agreed. Exchange them for plain ol' ACDelcos, factory equipment. There's nothing printed against using Bosch, but I know several members here have had strange spark problems after switching away from ACD's. Another brand with a good track record is NGK, but their stuff is generally quite expensive.

[aurorabrain]

The bosch platinums started misfiring in a friends Aurora 1 month after install. He now runs NGK Iridums with no problems.

[mjh48059aa]

I've just checked the plugs in my car today. Not fun!

I don't care for the part where after you loosen up the plugs, that you still have to fish them out of there with needlenose pliers. But it's those back plugs that were the struggle. I snapped a plastic vacuum hose twice while rerouting it in order to place it where it needed to go once I did check all eight plugs. I've got it patched up, though. Runs better now than it did before I got to work on it, though I pulled the fuse to the computer to clear the codes in it just in case. I don't know why, but it's just a force of habit, I suppose. Three of the plugs were gapped at .055 instead of .050 like they were supposed to, but they all look good, aside from the one that looked like it had a thin film of oil on it.

Seeing that these are aluminum heads, I made sure I found the torque settings on those plugs before I even bothered starting, just because it's WAAAY too easy to strip the threads on these heads if you mash the plugs in like with cast iron heads. 11 ft/lbs sounds right on the money to me considering what the heads are made out of.

Next up: Taking care of that high speed vibes in the back end.

[austinator]

Next time you do it get a spark plug socket with the rubber lip that holds them in so you don't have to fish them out. That's what they're designed for.

[mjh48059aa]

That's on my shopping list for next week, along with some extra vacuum line.

austinator said:

Next time you do it get a spark plug socket with the rubber lip that holds them in so you don't have to fish them out. That's what they're designed for.

[motbooz]

Just did my plugs and wires last week. Chose stock ACD platinum plugs and BW wires (couldn't see going to $130 for ACD).

My tip: definitely get a ratcheting 10mm box wrench for the bolts that mount on the base of the coil pack. I had only a fixed line wrench and turning the bolts a 1/8th turn at a time is criminal.

I used my plug socket with the rubber boot liner and it grabbed the plugs fine. Shouldn't be any worries there.

[RapMastaC1]

Add another to the just finished up list. I did the front ones a few months ago and gave up on the back ones (I didn't have enough time). So I finally decided to tackle it. I started at midnight and finished at about 1.00. The part that took me the longest was the removal of the coil pack. Another hard part is after you have tightened the new spark plugs in and you pull the ratchet out and the special spark plug bit is stuck on the plug. I had to use plyers to get it out, the last two were easy tho.

On the last two plugs, on the passenger side, I looked at them and they had a lot of gas on them, going almost all the way to the white, it was going up the thread all the way, but there was none on the sparker bit. Is this something I should be worried about. I also noticed that around my head where the gasket is, there is a lot of grime and stuff, is this something to worry about too? My Caddy's is like that so I assume it's just natural on that many miles.

And yeah, my coil pack only had three (not by choice though) seems like someone else did this before because the bolt on the driver's side rear (bottom) was not there, and the vacuum thing (whatever that flat black thing is above the coil pack) had the things that held it to the firewall and one of them was slightly snapped (the other side is fine, it stays in place). But the plugs were in there freakin' tight, which kind of has me worried...

[jason]

So I guess the bottom line is use an extension that locks to the socket a spark plug socket with a rubber liner, remove the coil packs, buy A/C Delco plugs and wires (recommended), don't be afraid to get up close and personal with the fire wall and above all be patient.

[scottydl]

jason said:

So I guess the bottom line is use an extension that locks to the socket a spark plug socket with a rubber liner, remove the coil packs, buy A/C Delco plugs and wires (recommended), don't be afraid to get up close and personal with the fire wall and above all be patient.

That is an extremely accurate summary of this type of project.

Rap, the grime around your intake gasket suggests a leak but they are not uncommon and not a huge concern unless a lot of oil is dripping out. The plugs that were fouled, about all you can do is check the new ones after a few thousand miles and see how they look. That'll tell you if there's another problem that needs to be addressed. Congrats on the getting the project done!

[Randy T.]

To keep your spark plug socket from sticking on the plugs put the boot lube on the spark plug before you put it in the socket. I know this sounds nasty but it worked great. The socket still holds the spark plug but it comes off very easy. I changed one wire at a time so I could get the right lengths. I also took each individual wire and set it beside the new wire. The places where I noticed wear, I put black tape on the new ones. I also wouldn't do this without a compressor or a vaccum. Those holes need cleaned out. I even had a wire brush that fit in there perfectly. Before I took the old plug out I blew out the hole then used the wire brush then blew it out again. Then after I put the new plug in I blew it out one more time. I gapped my plugs at .60 that's what it says on my sticker under the hood. It is a '97 Autobahn.

I changed my plugs and wires Fiday afternoon, took about 2.5 hours. I used AC Delco plugs and Duralast wires from Auto Zone. The Duralast wires were 69.99, they were the cheapest ones Auto Zone had. I chose them because they weighed a pound more then the Bosch that cost 89.99, and they also have a lifetime warranty.

Thanks to everyones experience I was able to correct the problems before I had them.

[aldrichd]

Thanks for all the advice.
Changed plugs on my 1999 today and it was pretty easy. I put in AC 41-950 plugs. The owners manual says AC 41-929. I went to O'Reilly and asked for the AC 41-929 and they couldn't find any and said that was not a good AC number. So he looked it up and said it took AC 41-950. The old plugs that I removed were AC 41-950. They were pretty clean and gapped from .48 to 50. It makes me believe that the plugs may have been changed before I bought it.
To keep the plug socket seal from sticking to the plug I put a drop of oil on the seal first. It has a nice seal so the plug will not drop out but still pops off real easy.
Putting everything back together was a breeze. The car started right up and ran smooth. (I'm always leery of cracking a new plug)
I didn't time myself because I ate lunch in between the front and back plugs.

[Randy T.]

aldrichd said:

To keep the plug socket seal from sticking to the plug I put a drop of oil on the seal first. It has a nice seal so the plug will not drop out but still pops off real easy.

Great minds think alike. What did you gap yours at? Everyone keeps saying .50 But both my '97's say .60.

[Randy T.]

aldrichd said:

I didn't time myself because I ate lunch in between the front and back plugs.

Sounds like a good place to eat lunch. Did you use the motor for a table?