Replacement of spark plugs (with gap) and wires?

Tiny
ANONYMOUS
  • MEMBER
  • 2005 BUICK LESABRE
  • 98,600 MILES
Looking for help with replacement of spark plugs and wires. Main question is how do I access the 3 plugs on the rear of the engine? Do I need to do anything special, such as tilting the engine forward?
Saturday, January 19th, 2013 AT 1:23 PM

27 Replies

Tiny
WRENCHTECH
  • EXPERT
If it has a bar running across the top, remove the bolt to rock the engine forward makes it way easier. This guide can help step by step with instructions in the diagrams below to show you how on your car.

https://www.2carpros.com/articles/how-to-test-an-ignition-system

Spark Plug Type .................... AC plug type 41-921

Gap 1.52 mm (0.060 in)

Check out the diagrams (Below). Please let us know if you need anything else to get the problem fixed.
Was this
answer
helpful?
Yes
No
Wednesday, December 19th, 2018 AT 2:17 PM
Tiny
JABUCK
  • MEMBER
  • 2004 BUICK LESABRE
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 73,844 MILES
What is the best, most effecient way to remove the spark plugs on the rear bank of the 3800 engine? From on top, underneath, or what? I need to change them, but I don't want to pay $110+ to get it done. I have a set of ramps to raise the car about 10 inches off the ground, but do not have access to a lift.
Thanks,
Joe
Was this
answer
helpful?
Yes
No
Sunday, April 25th, 2021 AT 1:01 PM (Merged)
Tiny
DENNYP
  • EXPERT
Change them from up top. Ratchet, spark plug socket, 3" extension. You may need to loosen/remove engine toque mount and rock the engine forward.
Was this
answer
helpful?
Yes
No
+8
Sunday, April 25th, 2021 AT 1:01 PM (Merged)
Tiny
WASECA
  • MEMBER
  • 2003 BUICK LESABRE
  • 2WD
  • AUTOMATIC
  • 142,400 MILES
How do you change rear three spark plugs?
Was this
answer
helpful?
Yes
No
Sunday, April 25th, 2021 AT 1:02 PM (Merged)
Tiny
WRENCHTECH
  • EXPERT
Hello,

I seen my guys in the shop undo the engine torque mount to roll the engine forward and then push wood blocks to hold the engine while they change the plugs.

There are some engines that make it very difficult to access some of the spark plugs but that engine is not one of the worst ones. If you just use a flex head ratchet with with a 3 inch extension, you should be able to access them.

IMPORTANT: Always use the reinstallation torque specification when installing NEW or USED spark plugs into a USED cylinder head. Use the initial installation torque specification ONLY when installing spark plugs into a NEW cylinder head that has NOT gone through a normal engine thermal cycle.

2.1. Use this reinstallation torque specification when installing NEW or USED spark plugs into a cylinder head that has gone through a normal engine thermal cycle.

Tighten
Tighten the spark plug to 15 N.m (11 lb ft).

2.2. Use this initial installation torque specification ONLY when installing spark plugs into a NEW cylinder head that has NOT gone through a normal engine thermal cycle.

Tighten
Tighten the spark plug to 27 N.m (20 lb ft).

3. Connect the spark plug wires to the spark plugs.
4. Install the fuel injector sight shield.

This guide should help

https://www.2carpros.com/articles/how-to-change-spark-plugs

Please let us know if you need anything else to get the problem fixed. Cheers,
Was this
answer
helpful?
Yes
No
+7
Sunday, April 25th, 2021 AT 1:02 PM (Merged)
Tiny
JRYDBERG
  • MEMBER
  • 2002 BUICK LESABRE
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 100,000 MILES
I have replaced the front 3 spark plugs without a hitch, but it appears that I have to drop the engine in order to get to the 3 rear plugs. Is there a way that I can replace the 3 rear plugs by myself? And if so, HOW DO I GET TO THEM?
Was this
answer
helpful?
Yes
No
Sunday, April 25th, 2021 AT 1:02 PM (Merged)
Tiny
ERNEST CLARK
  • EXPERT
It's not necessary to drop your engine. You just need the proper tools.

A spark plug socket with a universal hinge would work the best. Then you'll need an extension. But the length will depend on what's obstructing that particular plug. (Each plug may require a different length).

Also, a magnetic spark plug socket will help you keep the spark plug from dropping. And if something against the firewall is in the way, you can remove it, then reinstall it when you're finished.

Wish you luck.
Was this
answer
helpful?
Yes
No
+1
Sunday, April 25th, 2021 AT 1:02 PM (Merged)
Tiny
JRYDBERG
  • MEMBER
  • 2001 BUICK LESABRE
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 100,000 MILES
I was able to replace my three front spark plugs, but can BARELY even see the wires for the rear 3. Someone told me I have to tip the engine forward, but I'm not sure how to release it to do so.
Was this
answer
helpful?
Yes
No
Sunday, April 25th, 2021 AT 1:02 PM (Merged)
Tiny
KNOWYOURAUTO
  • MEMBER
With the advent of the transaxle cars become more squished into the engine compartment than ever before. This model is actually one of the easier styles to do but still requires a lot of patience and a work by feel.

2001 does not have the "dog bone" style engine that your friend was describing to tilt the engine forward. This was the style.


https://www.2carpros.com/forum/automotive_pictures/435113_Engine38_1.jpg



For your application you will need a universal joint (wobbly) in 3/8" drive along with a 4 inch extension for your spark plug socket. Before trying to pull the plug wires straight off make sure you can rotate the rubber boot both directions about 180 degrees so it doesn't rip the insulation apart. Otherwise you'll be buying new wires.

Good luck,
Was this
answer
helpful?
Yes
No
+5
Sunday, April 25th, 2021 AT 1:02 PM (Merged)
Tiny
DANTZLER
  • MEMBER
  • 2001 BUICK LESABRE
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 160,000 MILES
I feel like the spark plugs are misfiring how to change the spark plug wires and spark plugs
Was this
answer
helpful?
Yes
No
Sunday, April 25th, 2021 AT 1:02 PM (Merged)
Tiny
KEN L
  • ADMIN
Hello, here is a guide and video that will give you an idea on what you are in for when doing this job.

https://www.2carpros.com/articles/how-to-change-spark-plugs

and

https://youtu.be/h3Jmg2HRVYk

Please use 2CarPros anytime, we are here to help and tell a friend.

Best, Ken

Was this
answer
helpful?
Yes
No
Sunday, April 25th, 2021 AT 1:02 PM (Merged)
Tiny
DRUZYF13
  • MEMBER
  • 2000 BUICK LESABRE
  • 3.1L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 6,000 MILES
I just changed my spark plugs and put Autolite iridium plugs in it. When I got up this morning I checked all my connections to make sure they were snug and they were. But now I'm hearing this low humming noise when I first press on the gas. Also causes noticeable vibration. What's my problem?
Was this
answer
helpful?
Yes
No
Monday, May 3rd, 2021 AT 10:16 AM (Merged)
Tiny
SCGRANTURISMO
  • EXPERT
Hello,

Did you make sure that the spark plugs are gaped properly and you have the correct firing order?I have included this information for you in the diagrams down below. Please go through this information, double check, and get back to us with what you are able to find out, please.

Thanks,
Alex
2CarPros
Was this
answer
helpful?
Yes
No
Monday, May 3rd, 2021 AT 10:16 AM (Merged)
Tiny
DRUZYF13
  • MEMBER
I actually have the right plugs I guess when I fired her up last night after swapping plugs it seems as if the newly found power and my heavy foot has fractured the honeycomb of the catalytic converter since the rattling is coming from there. It's very minor and only on initial rpm of first gear. How long do you think I have before repair or any suggestions?
Was this
answer
helpful?
Yes
No
Monday, May 3rd, 2021 AT 10:16 AM (Merged)
Tiny
DRUZYF13
  • MEMBER
Oh, and the engine is a rebuild with 6,000 miles on it. So the catalytic converter has probably 200,000 miles on it.
Was this
answer
helpful?
Yes
No
Monday, May 3rd, 2021 AT 10:16 AM (Merged)
Tiny
SCGRANTURISMO
  • EXPERT
Hello,

I would recommend getting the catalytic converter replaced as soon as possible. A plugged catalytic converter can cause a litany of problems, with severe engine overheating from being choked out by exhaust back pressure since it has no where to go, first on the list. You will know when this happens, your vehicle will start to overheat and your vehicle's power will start to fade. I do not recommend letting it go this far, but just in case it does, there it is. Let us know how it turns out, please.

Thanks,
Alex
2CarPros
Was this
answer
helpful?
Yes
No
+1
Monday, May 3rd, 2021 AT 10:16 AM (Merged)
Tiny
DRUZYF13
  • MEMBER
Thanks man I really appreciate it. I already ordered one off Amazon for $150.00. Do I need anything else with it, like seals or gaskets?
Was this
answer
helpful?
Yes
No
Monday, May 3rd, 2021 AT 10:16 AM (Merged)
Tiny
SCGRANTURISMO
  • EXPERT
Hello again,

The only other thing you would need would be a couple of muffler clamps(matched to the diameter of your exhaust and a sawzall or some type of cutting device to cut the old one out of the exhaust. Slide the new catalytic converter in place and clamp.

Thanks,
Alex
2CarPros
Was this
answer
helpful?
Yes
No
Monday, May 3rd, 2021 AT 10:16 AM (Merged)
Tiny
DUSTIN PECK
  • MEMBER
  • 2000 BUICK LESABRE
  • 3.8L
  • 6 CYL
  • FWD
  • AUTOMATIC
  • 204,000 MILES
I changed spark plugs, got good wires and opened my air filter, now car smells like exhaust and hesitates when under load or trying to down shift.
Was this
answer
helpful?
Yes
No
Monday, May 3rd, 2021 AT 10:17 AM (Merged)
Tiny
HARRY P
  • EXPERT
What brand of spark plugs and wires did you use? In my experience, GM's with the 3800 engines are very particular about the plugs and wires that are used in them. Basically, anything other than Delco plugs and wires fail in short order

Also, is the check engine light on? If so, have you had it scanned?
Was this
answer
helpful?
Yes
No
Monday, May 3rd, 2021 AT 10:17 AM (Merged)

Please login or register to post a reply.

Sponsored links