I just priced plugs for my 2001 Impala 3.8--- at autowarehouse.com
they range from $2.30 to $12.50 each.
This isn't a job I want to do more than once [jack a frigging engine
forward to change plugs? sheesh]-- but I also hate to spend more than
Can anyone point me to a comparison of plugs to see what the real
The car has 80K on it- is now a second car & does mostly city driving
but will be the 'long trip' car, too, so it will be called on to do
highway driving a few times a year.
[Actually- how many folks would change plugs and wires on this car
when it is running fine today?]
Any of the Iridium plugs should work well and give you another 80k miles
easily. NGK, Denso or AC-Delco. I would pick the lowest cost of those
three. I would also stay away from Bosch Platinums as the tiny center
electrode is reported to give problems on some applications.
$2 plugs for your car are likely to be conventional and will work fine
for a shorter life span, probably in the 15k-30k range. Platinums are
the next step up in service life and Iridiums are the longest lasting.
Definitely go with ACDelco plugs. I put NGK's in my old Bonnie's 3.8, and it
lost gas mileage. When I got my new Bonnie (1996) I used AcDelco and she
runs great, and gets around 28MPG on the highway, and that's with the
supercharged engine. I went with ACDelco wires as well.
Hmmm, the last "AC-Delco" Iridium plugs I purchased were stamped "NGK"
on the actual plug. GM has quit making spark plugs itself and
outsources production of the stuff that goes in those little blue and
The plugs in my car are rated for 100k miles. At 110k, the car was in the
shop so I figured I have the plugs changed at the same time. The
difference? None. Same easy starting as when it was new, same fuel
mileage. As expected, a wire broke while Bob was changing the plugs. He
said it is common for the ones on the rear trying to pull them off the old
plugs. Worth it? I guess since the car was in the shop it was convenient
and now they will last me the life of the car. My 91 Regal is on it second
set of plugs at 148k. The first set was changed at 80k.
If the OP does change them, get equal to the OEM and they should last a long
Don't believe everything the service manuals tell you. I have a 2001
3.4 Impala, and my Helms book said the same thing. Ridiculous. You
have to be careful, but it's not really a problem - I've pulled and
reinstalled my plugs with no hassle.
Most of the work will be done by touch - but they should be reachable.
Be sure to use a real spark plug socket (with the rubber piece inside
to grip the plug.) And of course, be careful and gentle upon
reinstallation to avoid stripping of threads - I always start mine by
hand, with just the socket and extension, before attaching the socket
It's like on my Colorado p/u - to pull the front spark plug, they (the
factory manual) say you have to pull a zillion connectors, then
totally remove the wiring harness. Uh, no. Not necessary. Or my
old BMW, where they said to change a heater core you had to chisel out
the steering column mounts. I don't frigging think so (and didn't
The guys who write these manuals badly need a reality check from their
- Larry A.
I changed the plugs on my wife's Impala around 50k, they are cheap enough
that replacing them at 50k instead of the recommended 100k isn't that much
more $. Stick with the AC Delco stuff. I unbolted the coil pack and moved
it out of the way to make it easier to get the rear and didn't have any
The real differences are located in your wallet. Buying something other
than the GM recommended for your car isn't recommended. New plugs will
last a hellofa long time nowadays since there is no more lead in gas.
Do you see yourself keeping the car past a 'hellofa' long time? As to
jacking the engine: I have a FWD Cadillac and I the 'procedure' is to
unbolt the rear of the engine and raise it to get to the rear bank of
plugs. I was able to get my arm around the engine and with a
combination of tools R&R the rear bank plugs. Start any plug by hand
only.....crossthreading is a no-no! Dab a bit of dielectric grease on
the threads/plug boot and get after it.
Heat breaks down plug wires over time. If those are the originals
(80K), I'd change them. Again, use recommended OEM plug wires. Proper
maintenance saves money and extends lifespan.....in most
everything.....even in people!
If you've got the original plugs AC Delco plugs in there now, why not
get the same type / # that is already in the car.
I went 180,000 miles on the plug wires in my Bonneville before they were
changed at around 8 years old. I wanted to change them at 110,000 when
it was 5 years old but the Parts Dept at Pontiac said I didn't need them
05 Park Avenue 45,044
91 Bonneville 307,187
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