My first spark plug replacement

97 Blazer
4.3
4x4
147K miles

I bought this Truck used - had 35K miles on it. I haven't had the spark plugs/wires/rotor replaced yet.

Should I be concerned that the plugs may be stuck in the block? This is my biggest worry.

Can you spray anything in there that would help loosen them up?

Any other gotchas? (besides #3 plug)


Thanks !

Nope, straight forward.

Use antoseize when installing the new ones and for the love of christ do NOT use bosch plats.

Only use the AC Delco Platinum.

Might want to invest in magnetic plug socket, and a 6" long, 20 degree "wobble" extension. It will prove to be invaluable when working around the shaft of your steering column to reach that #3 plug. ;) You may have better luck jacking up the driver's side of the truck and dropping the wheel off. Allows nearly dead-center access to all of the plugs on that side. Wear gloves and longsleeves too... I look like I wrestled a stray cat when I finished my plug job on my '95.

Hopefully, you will have better luck!

Wear gloves and longsleeves too... I look like I wrestled a stray cat when I finished my plug job on my '95.

Me too! LOL!

Make sure you have lots of extensions and elbows to get into the 3rd one.

Also, other than the two front cylinders, do the rest of them through the wheel wells.

Soooo much easier.

97 Blazer
4.3
4x4
147K miles
I bought this Truck used - had 35K miles on it. I haven't had the spark plugs/wires/rotor replaced yet.
Should I be concerned that the plugs may be stuck in the block? This is my biggest worry.
Can you spray anything in there that would help loosen them up?
Any other gotchas? (besides #3 plug)

Thanks !

Being a newbie to the whole process, the advice so far posted is exactly what you should do (as they previously guided me through the process just recently). The only advice I would add is to take off the drivers side engine mount, supporting the engine with a wood block (under oil pan) and jack engine slowly up until you can get to the spark plug behind the steering wheel column. No matter what extensions I had, I could not get it out (because I tried that method) without jacking it up. It takes a few more minutes to do, but it is was worth not having a broken off #3 spark plug.

As far as the spark plugs seizing, I barely changed the factory plugs at 96k miles and they came out without any fuss.

As far as the spark plugs seizing, I barely changed the factory plugs at 96k miles and they came out without any fuss.

The factory plugs are usually coated with an anti-sieze compound. If you are not replacing your spark plugs every 30K miles, (Which is pointless if you put AC-Delco platinums back in it) it is best to use a small dab of anti-sieze. Remember back to when it was easy getting those factory plugs out, and you now know why. ;)

A mechanic buddy of mine has been running on Bosch "Super" plugs in his Blazer. They are not platinums, just a plain old OE style plug. For the heat range needed for our engines, the Supers are a full 1/4 inch shorter than the GMAC-Delco replacement. He says sneaking the plugs into place using his fingers alone and the "super" plugs made his job 10X easier. The exta 1/4" of room makes it easier to slip your socket over them to give them the final tightening. However, they have to be gapped/replaced 3x as often. (Only go about 3 years/30-35K miles and they are spent) An alternative to think of if you enjoy working on your truck. No need to go through contortions or removing the engine mounts in this case. That may be beyond the scope of our newbie friends' toolbox to tackle. :)

Thanks guys! I have the new AC Delco Platinums ready to go. My first attempt will be with extensions and patience. :)

Being a newbie to the whole process, the advice so far posted is exactly what you should do (as they previously guided me through the process just recently). The only advice I would add is to take off the drivers side engine mount, supporting the engine with a wood block (under oil pan) and jack engine slowly up until you can get to the spark plug behind the steering wheel column. No matter what extensions I had, I could not get it out (because I tried that method) without jacking it up. It takes a few more minutes to do, but it is was worth not having a broken off #3 spark plug.

As far as the spark plugs seizing, I barely changed the factory plugs at 96k miles and they came out without any fuss.

I'm sorry, but removing an engine mount and kacking up the engine for one plug?

Little ridiculaous don't you think.

Two extensions and an elbow and it is licked.

Just curious but why is it suggested not to use Bosch Platinums?

They foul easily, cause misfires, and rough idle.

Just curious but why is it suggested not to use Bosch Platinums?

And they have been known to be a problem in the 4.3L's.

They foul very quickly.

I finally got to this job over the weekend. Replaced the plugs, wires, cap, and rotor. Was a pretty straight-forward job. My buddy handled the driver's side #3 plug with a "5/8 swivel socket" and extensions. It's long enough for a plug, but shorter than a standard deep-well socket. That socket made a big difference and lessened the amount of cursing in the room.

There is one thing we ran into: The AC-Delco plugs come pre-gapped to 0.060".

My owners manual, Chilton book, and GM service info states the gap for a 4.3L VIN W to be 0.045".

I gapped mine to 0.045".

Anyone else run into this? So far the truck starts and runs like new.

My owners manual, Chilton book, and GM service info states the gap for a 4.3L VIN W to be 0.045".

I gapped mine to 0.045".


That is quite fine and correct. If you *must* regap a platinum plug, use the "wedge" type gapping tool that looks like a slowly, graduated wedge going around the edge, with the gap increments increasing as the wedge gets fatter. Using a wire type gapping tool that has loops of wire bent into "D" shapes on the outside can be detrimental on platinum plugs.

Gently use the tooth on the tool to bend the electrode just enough to get the measurement done with the lightest of contact from the wedge. Forcing a wire loop between the electrodes with your typical gapping tool will break the platinum button(s) off of the plug. ;)

Great to hear the beast is still running strong. Take care of her, and she'll take care of you!

I finally got to this job over the weekend. Replaced the plugs, wires, cap, and rotor. Was a pretty straight-forward job. My buddy handled the driver's side #3 plug with a "5/8 swivel socket" and extensions. It's long enough for a plug, but shorter than a standard deep-well socket. That socket made a big difference and lessened the amount of cursing in the room.

There is one thing we ran into: The AC-Delco plugs come pre-gapped to 0.060".

My owners manual, Chilton book, and GM service info states the gap for a 4.3L VIN W to be 0.045".

I gapped mine to 0.045".

Anyone else run into this? So far the truck starts and runs like new.

Sorry bro, you have to remove and regap them.

They some pregapped to 0.060 which is the EXACT setting for your truck.

Your gap now is too small and it will affect your performance and fuel economy.

Sorry bro, you have to remove and regap them.

They some pregapped to 0.060 which is the EXACT setting for your truck.

Your gap now is too small and it will affect your performance and fuel economy.

BLT, thanks for your feedback. Are there any other concerns about the gap being too small? I won't be able to reseat the plugs for a couple of weeks and I want to make sure no engine damage will occur.

I hardly doubt you don't have an hour to reset the plugs properly with the proper gap.

Just get it done.

It will affect your fuel economy, and could cause problems with your O2 sensors.

Get out there and fix it.

Everyone has an hour.

Hi guys,

I'm about to do this procedure by myself for the first time on our '95 Blazer 4.3 VIN W engine.

BlazerLT, heaven knows you've helped me out big time on this forum, but I'm a bit worried about this last post. You sure he needs to redo this job and regap his spark plugs? I'm looking in my Chilton's manual, and I know it isn't always right, but it says that 0.045 inches is the right distance for his '97 Blazer with 4.3L engine and that 0.035 inches is what I should use in my '95 Blazer.

Is there something special about them spark plugs being platinum tipped that requires the 0.060 inch gap? Or is the Chilton's manual just way wrong? The Chilton's manual acts like 0.060 inches is what is needed for the 4 cyclinder engines used in some of the S-Series pickup trucks.

Thanks in advance for your clarification and help in this.

Cheers,
-- recurve

Hi guys,

I'm about to do this procedure by myself for the first time on our '95 Blazer 4.3 VIN W engine.

BlazerLT, heaven knows you've helped me out big time on this forum, but I'm a bit worried about this last post. You sure he needs to redo this job and regap his spark plugs? I'm looking in my Chilton's manual, and I know it isn't always right, but it says that 0.045 inches is the right distance for his '97 Blazer with 4.3L engine and that 0.035 inches is what I should use in my '95 Blazer.

Is there something special about them spark plugs being platinum tipped that requires the 0.060 inch gap? Or is the Chilton's manual just way wrong? The Chilton's manual acts like 0.060 inches is what is needed for the 4 cyclinder engines used in some of the S-Series pickup trucks.

Thanks in advance for your clarification and help in this.

Cheers,
-- recurve

Whta plug did you use?

Where did the .060 inch come from? My owners manual says .045 inch

My haynes says:

4.3L V6

1994 and 1995
Type...................AC CR43TSM or equivalent
GAP....................0.045 inch

1996 on ..............AC 41-932 or equivalent
GAP....................0.060 inch

It has been said by many on this forum that it should be 0.060, I just want to know where that came from.

BTW. I gap mine at 0.060

Depends on the plugs really.

I was planning on getting the AC Delco Platinum tipped spark plugs and doing the job this coming weekend.

I have both the Haynes and the Chilton's manual. You are right Blazee, both books give different specs - they don't match up.

So you guys think 0.060 inch gap is good for a 4.3L engine on a '95 Blazer (and a '97 for that matter)? I'll be using the AC Delco platinum tipped plugs :-)

Cheers,
-- recurve

1.) Platinum plugs are not required on 1995s and are not recommeded. Buy #1 Delco Rapidfires or Standard CR43TSM plugs both can be gapped at 0.045.

2.) 1997, use delco platinum or delco rapidfire #12 gapped at 0.060

Perfect!

Thanks a million,
-- recurve

Not sure why the obsession with AC Delco plugs here??? Seems like there is some history of bad junk happenin with Bosch, and as a result I know I won't get 'em..
Here's my $.02.. .My brother is a PHD Mechanical engineering student who also happened to intern for about a year with Autolight at which they'd buy and research other plugs and develop new methods of assembling them etc..they'd also do durability testing, heat testing, you name it testing .. the rankings after all tests were siad and done were #1 NGK platinum.#2 Autolight platinum... he said he wouldn't trust anything else.

These plugs have the perfect resistence for our truck's ignition system.

Plus they are usually cheaper and can be purchased very cheaply off of ebay.

Sorry bro, you have to remove and regap them.

They some pregapped to 0.060 which is the EXACT setting for your truck.

Your gap now is too small and it will affect your performance and fuel economy.

ok.. i have the same blazer with 4.3L. and i already have my blazer with the .045 gap. and the performance is very good. ok.. so.. are you sure about this 0.060 ???

thanks
Nalgman

Ok, I just changed my plugs and wires using y'all's method and all I got to say is that I would like to meet the guy who designed the engine compartments to these trucks and kick him square in the cookies!!!! :mad:

ok.. i have the same blazer with 4.3L. and i already have my blazer with the .045 gap. and the performance is very good. ok.. so.. are you sure about this 0.060 ???

thanks
Nalgman

There are different gaps for different engines for different years.

On your 1990, I think it is supposed to be 0.045.

1.) Platinum plugs are not required on 1995s and are not recommeded. Buy #1 Delco Rapidfires or Standard CR43TSM plugs both can be gapped at 0.045.

2.) 1997, use delco platinum or delco rapidfire #12 gapped at 0.060


ok....so 1995s, rapidfires are recommended
and on 1997, Platinums are recommended (with rapid fires as a secondary)

What about 1996? Can i use the Platinums on my 1996 or should I stick with the rapidfires like I put in there last tuneup?

1996 is the same as 1997 rules.

ok, so platinums are a better choice over the rapidfires for my blazer then? Guess I will definitly replace them on this upcomming tuneup

For 1996+, Plats are better.

so here another question..

ok. everybody says the gap for the sparkplugs for my blazer s-10 4.3L 6V are 0.045.
so. here is my question... in the page of ACDelco says .035 for this engine. 1990 CHEVROLET S10 BLAZER V6 4.3L 262cid GAS FI N Engine VIN = Z

what is better? or what is your recommendation?

thank you!

Nalgman

It is 0.035

Anyone know if there is an advantage to using "high performance" wires/caps, etc. in the 4.3L ? By high performance I mean something like Accel, Moroso, MSD, Splitfire...

Anyone know if there is an advantage to using "high performance" wires/caps, etc. in the 4.3L ? By high performance I mean something like Accel, Moroso, MSD, Splitfire...

Nope, not on a stock engine.

BlazerLt, what plug do you use in your 95, ac delco rapidfire at .045, or the plat. at .060? I think I used the plat. at .045 for my last tune up. I planned on replacing the plugs/wires/cap/rotor/airfilter/ at my next oil change, probably this week. Just wondering what parts are recommended for my stock 95 BlazerLT, trying to do this the right way. Thankx.
-Ice

Don't use Plat on that year.

You use Rapidfires or the standard AC Delco gapped at 0.045

my 4.3 vortec 98 says the gap is 0.060 on a sticker in the engine compartment. Where did you see 0.045

95 and earlier use a .045 gap. Says so on the emissions sticker on my 95 CPI engine. Says so in Chilton's and Haynes too. 96 onward see a .060 according to my books and wherever I managed to peek under a buddy or two's more modern trucks with the advanced high energy ignition system.

96+ they also used AC Delco Platinums.

Yup, 10-4 on that BlazerLT - though the books say 100K+ miles between tuneups, I read a paper somewhere from GM that stated that the ideal lifetime of a platinum plug is about 3 years, as opposed to the 1.5~2 years of service seen out of a standard nickel plated plug. Damn, sure wish I could find that paper or a reference to it now...

Plugs can last longer than that, the cap and rotor won't though.

My recent post on it tells you why.

You guys keep saying Cap and Rotor about a spark plug? what is that?

You guys keep saying Cap and Rotor about a spark plug? what is that?

There talking about the distributor cap and the rotor inside the distributor.

Anyone use the methods posted here on a 2002 blazer? Before I jack up the engine, unbolt the motor mount, etc. I want to know I'll be able to get to those BLASTED drivers' side plugs. What about the other side? Are those accessible with a wheel removal?

Thanks.

**EDIT**

I pulled the wheels off and you all were right... all six were right there. Save #3 of course, which was still behind the steering column. But if you slide that orange rubber protector out of the way, set the steering right so the flat side of the column is facing up, you can get straight into the plug with a plug socket and extension.

SO I take it on my 1996 blazer with the W code 4.3L, i should not have installed bosch plat? Replace with AC Plat?

95 and earlier use a .045 gap. Says so on the emissions sticker on my 95 CPI engine.

My Chilton manual said .035 for a 93 but the under hood sticker said .045.

See the following thread for some spark plug installation pics.

(http://www.automotiveforums.com/vbulletin/showthread.php?t=507211)

Old thread......