:::First Tuneup On 2008 Chevy Impala

[NDL]

Hello y'all

.

I just ordered some iridium plugs for my Wife's 2008 Chevy Impala (3500 V6). Car has 120k, and I am going to be giving the car it's first tune up.

I'm a "better safe than sorry" kind of guy, so I have a few questions:

The heads are aluminum, so I plan on changing the plugs on a cold engine. They're the factory plugs. Should I be concerned about them not coming out?

Also, I took a look at one of the new plugs, and there's no crush washer attached to it. The box was sealed tightly shut, so nothing fell out. Are they now using crush washer's anymore on plugs? Plugs are Denso Iridium.

Finally, is the rear bank of plugs a PITA to do, even with the dogbones loosened up? I got a swivel head ratchet for this job, hoping it'd make it a little easier. Are the rear plugs easy for a novice to get at?

Thanks in advance, for any assistance.

 

[WobblyElvis]

Info I have says, clean the area around the plugs before removing, remove air cleaner outlet duct, remove manifold cover, and remove plug wires if required.

No mention of a lube for the plug threads, torque to 11 ft lbs.

 

[oilmutt]

I have the same engine(3.5 L v6) in my wife 2005 Malibu.Started to change the plugs at 115k miles,it took me over an hour to get the front 3 out ,they were rusted in the block.I used a ratchet extension and short blocks of 2x4.My mistake should have changed them at about 75k miles. Spend the next hour trying to get the firewall 3 plugs,but broke off 2 plug wire guides.Finally to it to the Chevy dealer and they charged $125 to change the 3 plugs and 6 spark plug wires,well worth it after my ordeal . the 3 fire wall plugs had no rest a looked almost new-go figure! By the way i have the service manual for the 3.5 engine and it states not to use anti-sees on the spark plugs.

 

[mjoekingz28]

The lack of a washer surprised me too. On my Silverado, the NGKs I got at the parts house were without washers. I wonder do they help seal the combustion chamber, alert you to how much torque to apply, OR both.

It seems they would increase compression by a fraction.

 

[Bgallagher]

Originally Posted By: oilmutt
I have the same engine(3.5 L v6) in my wife 2005 Malibu.Started to change the plugs at 115k miles,it took me over an hour to get the front 3 out ,they were rusted in the block.I used a ratchet extension and short blocks of 2x4.My mistake should have changed them at about 75k miles. Spend the next hour trying to get the firewall 3 plugs,but broke off 2 plug wire guides.Finally to it to the Chevy dealer and they charged $125 to change the 3 plugs and 6 spark plug wires,well worth it after my ordeal . the 3 fire wall plugs had no rest a looked almost new-go figure! By the way i have the service manual for the 3.5 engine and it states not to use anti-sees on the spark plugs.


+1 I have had similar issues as well. I have started taking my plugs out every 50k and checking them out anyways. That way the first time I go to change them they have been removed at least once.

I would recommend to use Delco iridiums as well. Don't use another brand. GMs can be funny if they don't have OEM plugs. I learned from experience with NGKs etc. in a GM

 

[PolarisX]

I could barely do the rear three on a 3800 car, I think I'm sending mine to the shop for plugs.

Malibu was obviously a breeze, did those at 90k.

 

[emmett442]

Most of the "domestic" manufacturers never used washers on the plugs. A tapered seat is most common.

 

[Bud_One]

Changed the original plugs/wires in our shop truck 2011 GMC Sierra - 4.8L V8 - 147k miles
No issues with removing any of them.
The replacement AC Delco Iridium plugs had no washers.

 

[Drew99GT]

I had no issues getting the rear 3 plugs out of my moms 08 Impala; I have a bunch of u joint extensions and just felt around, made sure the socket was tight on the plug, and with u joints and a cheater pipe was able to get enough leverage on each plug to get them out. I made sure and used anti sieze on the new ones and it helps to remove the coil packs as well. Was actually easier than 3400s and 3800s I've done.

Most GMs I've done have tapered seat plugs instead of crush washers; has been that way forever. Just snug them up hand tight, and tighten them up with light to moderate force. Don't go Hercules on them!

 

[NDL]

Originally Posted By: WobblyElvis
Info I have says, clean the area around the plugs before removing, remove air cleaner outlet duct, remove manifold cover, and remove plug wires if required.

No mention of a lube for the plug threads, torque to 11 ft lbs.


Appreciate the tips

...

Originally Posted By: oilmutt
I have the same engine(3.5 L v6) in my wife 2005 Malibu.Started to change the plugs at 115k miles,it took me over an hour to get the front 3 out ,they were rusted in the block.I used a ratchet extension and short blocks of 2x4.My mistake should have changed them at about 75k miles. Spend the next hour trying to get the firewall 3 plugs,but broke off 2 plug wire guides.Finally to it to the Chevy dealer and they charged $125 to change the 3 plugs and 6 spark plug wires,well worth it after my ordeal . the 3 fire wall plugs had no rest a looked almost new-go figure! By the way i have the service manual for the 3.5 engine and it states not to use anti-sees on the spark plugs.


Originally Posted By: oilmutt
+1 I have had similar issues as well. I have started taking my plugs out every 50k and checking them out anyways. That way the first time I go to change them they have been removed at least once.

I would recommend to use Delco iridiums as well. Don't use another brand. GMs can be funny if they don't have OEM plugs. I learned from experience with NGKs etc. in a GM


That's what I am worried about - that the [censored] things welded themselves to the head.

Originally Posted By: mjoekingz28
The lack of a washer surprised me too. On my Silverado, the NGKs I got at the parts house were without washers. I wonder do they help seal the combustion chamber, alert you to how much torque to apply, OR both.

It seems they would increase compression by a fraction.


Originally Posted By: emmett442
Most of the "domestic" manufacturers never used washers on the plugs. A tapered seat is most common.


Originally Posted By: Bud_One
Changed the original plugs/wires in our shop truck 2011 GMC Sierra - 4.8L V8 - 147k miles
No issues with removing any of them.
The replacement AC Delco Iridium plugs had no washers.


Thanks guys! Appreciate the info...

 

[901Memphis]

Had to have the shop do the plugs on my Century with the 3.1L engine. I don't know I would have done it. I hear they loosen the dog bones and use a ratchet strap to hold the engine for the rear 3 otherwise it's impossible since the engine is so close to the fire wall.

 

[slacktide_bitog]

The OE plugs are NGK iridium, so they will come out with no trouble, since they apply a special plating to the threads ofthe plugs (which the new ones will also have).

 

[mjk]

and who makes AC Delco? NGK.

Originally Posted By: Bgallagher
Originally Posted By: oilmutt
I have the same engine(3.5 L v6) in my wife 2005 Malibu.Started to change the plugs at 115k miles,it took me over an hour to get the front 3 out ,they were rusted in the block.I used a ratchet extension and short blocks of 2x4.My mistake should have changed them at about 75k miles. Spend the next hour trying to get the firewall 3 plugs,but broke off 2 plug wire guides.Finally to it to the Chevy dealer and they charged $125 to change the 3 plugs and 6 spark plug wires,well worth it after my ordeal . the 3 fire wall plugs had no rest a looked almost new-go figure! By the way i have the service manual for the 3.5 engine and it states not to use anti-sees on the spark plugs.


+1 I have had similar issues as well. I have started taking my plugs out every 50k and checking them out anyways. That way the first time I go to change them they have been removed at least once.

I would recommend to use Delco iridiums as well. Don't use another brand. GMs can be funny if they don't have OEM plugs. I learned from experience with NGKs etc. in a GM

 

[Huie83]

I just did the plugs on our 2010 Impala with the 3.5 @ 110K. I had no issues getting the plugs out. The rear bank isn't as bad as the internet leads you to believe. I just took the main coil pack off the back of the intake, disconnected the plug wires and that that frees up enough room to get your hands back there.

The plugs don't use a crush washer. Use some anti-seize and torque them to 11 foot pounds or 1/8th-1/4 turn (that's what I did per the instructions on the box). I used OEM AC Delco Iridium's as the poster mentioned above. They are fairly inexpensive and you know they are going to work for another 100K... The OEM plugs are not NGK's as someone else said. We purchased this car new and teh plugs I pulled out were Delco iridium's, same as the new OEM ones.

The OEM plugs looked great @ 110K, I don't notice any difference in performance or MPG's with the new plugs. I'll probably leave these in another 150K.

 

[slacktide_bitog]

Originally Posted By: Huie83
I just did the plugs on our 2010 Impala with the 3.5 @ 110K. I had no issues getting the plugs out. The rear bank isn't as bad as the internet leads you to believe. I just took the main coil pack off the back of the intake, disconnected the plug wires and that that frees up enough room to get your hands back there.

The plugs don't use a crush washer. Use some anti-seize and torque them to 11 foot pounds or 1/8th-1/4 turn (that's what I did per the instructions on the box). I used OEM AC Delco Iridium's as the poster mentioned above. They are fairly inexpensive and you know they are going to work for another 100K... The OEM plugs are not NGK's as someone else said. We purchased this car new and teh plugs I pulled out were Delco iridium's, same as the new OEM ones.

The OEM plugs looked great @ 110K, I don't notice any difference in performance or MPG's with the new plugs. I'll probably leave these in another 150K.


The OE ACDelco iridium plugs for your car (part number 41-100) are in fact made by NGK. Assmbled in USA of Japanese parts.

BTW, NGK says never to use anti-seize on any of their plugs