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Pontiac Repair/Engine question..


QUESTION: Mr. Puccio...
I have a 2001 Buick LeSabre with the 3.8L V06 (front wheel drive).  Just yesterday the engine suddenly started running rough...and when I opened the hood, it was rocking back and forth...maybe three or four inches.  I was still in my neighborhood, and was able to drive it home...maybe 200 yards or so.  But it continued to run rough and shake.  I haven't put the scan tool on it yet (need to find it.)  And I know the info isn't much to go on, and you're not a miracle worker.  But can you give any suggestions as to what COULD be responsible for the engine shaking like that?  Anything info you can share would be GREATLY appreciated.
Warm regards...and Merry Christmas!

ANSWER: HI david:
with it running that poorly I'm sure it's only running on 4 cylinders. so either a coil went down or the ignition module is bad that runs the coil that went down. once you find out what coil it is just swap the coil with one of the other 2 and see if the sprak returns. if swapping the coils that spot on the module the coils starts to work the coil is bad. if that spot the coil is still dead the ignition module is the cause. good luck and happy holidays to you. Oh one thing if it is indeed a ignition module that is bad replace it ONLY with an AC delco module. either one form a dealer or an ac delco parts dealer in your area. trust me you'll be sorry if you go after market

---------- FOLLOW-UP ----------

QUESTION: Mr. Puccio...
A little follow-up:  I put my code reader on the car, and one of the codes was a P0300 indicating cylinder misfires.  So I bought a new ignition module, 3 new ignition coils, some new spark plug wires, and am going to get new spark plugs and just replace all the above.  (I'm a pretty good-sized's going to be a hoot getting at those back three spark plugs.  But what the hell.  If I didn't wind up with skinned knuckles, it wouldn't seem like I've been working on the car.)
In addition, I also got a couple of P0442 "gas cap" codes, and I've also got a new OEM gas cap and will see if that helps.  I also got a P0741 and a P0742 torque converter codes.  I haven't Googled around, and will do so trying to find out what to do before I pester you with that.
My main question right now:  I've seen some spark plugs that...instead of just one side electrode, have two or even four.  And that ones that I've seen (and are considering getting for this job) claim that they are pre-gapped, and that you don't have to gap them yourself.  I've never used spark plugs like that, and wondered what you thought about them.  Do they work well?

Only use AC Delco spark plugs the ones that fit that car are either platinum or iridium plugs they are what is designed to be in the car and nothing else. I'm a firm beliver of what ever you drive (brand) put the original equipment electrical parts back in anything after market your just asking for issues. those split fire magic MPG increasing spark plugs are a just a hoax. They do not work you can't split the spark into 2 electrodes it take which ever one is easiest to jump and fire the plug off. if they were so good and magical the factory would use them.
the gas cap will  more then likey not fix that code the fuel filler next is more then likely rusted at the sealing surface where the gas cap seal against. you can use a 3m scotch brite pad and clean the rust off the surface and put some silicone lube on the surface to rtry to stop the rust from building up that rust damaged the seal on the cap. if you don't do anything with the pipe it will damage a brand new cap before long. as for the transmission codes it could be an electrical failure or the torque converter is actually slipping. with out seeing it I can't tell you for sure what the issue is.

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Todd Puccio


General auto repair,electrical issues,driveability issues,anti-lock brakes,SIR systems,HVAC,engine performance,Gm specific. I have worked at my current dealership since the 1990 model year anything much older than that I have limited exposure to. I do not have very much transmission experience so those question you may want to ask of another expert. When you send me a question let me know the exact make/model/engine and year for the car or suv you have it makes it easier to answer the questions that way. If your happy with the answer I gave you please feel free to Donate. This is a free service to you and I am not compensated at all by this web site. I have 22 years of experience to share with you and my knowledge wasn't free to me. I had to pay for my education.


Experience in the area: I have been a technician in GM dealerships for over 22 years and I am a ASE master technician. I work at a Buick and GMC truck store Previously I worked at a Pontiac GMC store for 18 years. I Served a a lead technician when dealership was on a team system. I just recently moved to a Buick,Hummer,Saab Store when my franchise was purchased by this dealership. Organizations: ASE master technician


Education/Credentials:High school diploma,2 year vocational school degree 2 year college degree. Associates degree in applied sciences (auto technology)Awards and Honors: GMC master technician

Awards and Honors
Master GMC truck technician Master ASE technician in 9 categories

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