2000 Lesabre Rough idle after cold start

[HotZ28]

You have not mentioned a possible bad ignition wire, or brand of wires that you replaced last year? Change the wires from 2 to 3 & see if the code changes. I have changed plug wires before with cheap aftermarket wires & two failed in less than 3-months!

 

[Frank2814]

You have not mentioned a possible bad ignition wire, or brand of wires that you replaced last year? Change the wires from 2 to 3 & see if the code changes. I have changed plug wires before with cheap aftermarket wires & two failed in less than 3-months!

Sounds good. I did remove wire and visually inspect it. I'll also check for continuity on it. Hopefully 2 & 3 are about the same length for 2 to reach 3. Thanks for the suggestions. I'll keep you updated. Here's something I was thinking about. We bought the car 2ish years ago. It's hot a little over 100k miles. It is a 2000 so it's close to 24 years old. I'm not sure but they probably put conventional oil in it. I put high mileage synthetic in all my vehicles. Could the synthetic oil be seeping past the piston rings and entering the combustion chamber and possibly be fouling the plugs and injectors? Should I switch back to conventional oil? We've done at least 3 oil changes before this issue began and I did recently have to add a half a quart after her last oil change. If it is the piston rings then I'll probably sell it.

 

[HotZ28]

Good luck & be sure to check this TSB/Recall in the link below! I should also mention that the synthetic oil you used, has nothing to do with the piston rings leaking. In fact, they may be better sealing with synthetic oil.

03054B Buick Fuel System Technical Service Bulletin

03054B Buick Fuel System Technical Service Bulletin

www.tsbsearch.com

 

[Frank2814]

Good luck & be sure to check this TSB/Recall in the link below! I should also mention that the synthetic oil you used, has nothing to do with the piston rings leaking. In fact, they may be better sealing with synthetic oil.

03054B Buick Fuel System Technical Service Bulletin

03054B Buick Fuel System Technical Service Bulletin

www.tsbsearch.com

Cool! Thanks for the info. I was out of town this weekend and I'm working tonight and tomorrow night. I plan on working on it Friday. I'll give you an update as soon as I figure something out. I super appreciate all your information and advice.

 

[Frank2814]

Good luck & be sure to check this TSB/Recall in the link below! I should also mention that the synthetic oil you used, has nothing to do with the piston rings leaking. In fact, they may be better sealing with synthetic oil.

03054B Buick Fuel System Technical Service Bulletin

03054B Buick Fuel System Technical Service Bulletin

www.tsbsearch.com

Alright. I think that I figured it out. Remember the car wasn't giving any codes when I initially started all this. I finally got a code when I was driving home from work. It was P0302 (cylinder 2 misfire).

I switched out the top coil pack (3 & 6) with the middle coil (2 & 5). I went on a test drive and ended up wit a P0306 (cylinder 6 misfire).

I replaced the bad coil pack and it runs fine.

I did clean and replace the filters in the fuel injectors since I already bought the parts and the puller machine. Probably a good idea because they were pretty dirt.

See attached pictures.

Thanks for all your advice. It definitely helped me figure out this problem.

Hopefully this will help someone else who's having a similar issue.

 

[Jim Sparr]

May I ask what brand of ignition coil did you use ? Where did you buy it? What did you pay for it ? I am new to this world of Buick LeSabre's and the 3.8 L V6. I like the design of the 3.8 L V6. It is excellent in many ways. For example , the coils are easily accessible on the front bank of the V6 engine. Compare that to the Chevy 3.1L V6 with all the coils hidden on the backside of the V6 between the firewall and the rear of the engine. On the Buick 3.8L engine, it is easy to trouble shoot by swapping the coils and see if the trouble follows or not. Now you know if the coil is the problem or something else is causing the problem.

 

[Frank2814]

May I ask what brand of ignition coil did you use ? Where did you buy it? What did you pay for it ? I am new to this world of Buick LeSabre's and the 3.8 L V6. I like the design of the 3.8 L V6. It is excellent in many ways. For example , the coils are easily accessible on the front bank of the V6 engine. Compare that to the Chevy 3.1L V6 with all the coils hidden on the backside of the V6 between the firewall and the rear of the engine. On the Buick 3.8L engine, it is easy to trouble shoot by swapping the coils and see if the trouble follows or not. Now you know if the coil is the problem or something else is causing the problem.

2000 BUICK Parts | RockAuto

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I went on Rockauto.com. The GM brand cost $50 a piece. There are some cheaper options if you want to try them.

I'm not sure if you read this whole thread but I wasn't getting any codes initially and thought it might be a vacuum leak. Once I got an engine misfire cylinder 2 code I swapped the coil packs and then got a engine misfire cylinder 6 code. So I replaced the bad coil pack.

I put a picture of my daughter's car earlier in the thread. Sometimes I think that I like her car more than she does. Lol

 

[Frank2814]

May I ask what brand of ignition coil did you use ? Where did you buy it? What did you pay for it ? I am new to this world of Buick LeSabre's and the 3.8 L V6. I like the design of the 3.8 L V6. It is excellent in many ways. For example , the coils are easily accessible on the front bank of the V6 engine. Compare that to the Chevy 3.1L V6 with all the coils hidden on the backside of the V6 between the firewall and the rear of the engine. On the Buick 3.8L engine, it is easy to trouble shoot by swapping the coils and see if the trouble follows or not. Now you know if the coil is the problem or something else is causing the problem.

Here's a cool picture I posted earlier.

 

[BuickGirlFromMars]

Nice pic. So I didnt read the wholle through, but what is your issues at this time? Did you resolve them all?

 

[Frank2814]

Nice pic. So I didnt read the wholle through, but what is your issues at this time? Did you resolve them all?

It was just a bad/intermittent coil pack. Since it wasn't giving any check engine light initially, I thought it was a vacuum leak, then I thought it might have something to do with fuel pressure. It wasn't until I was driving home from work that I got a check engine light on cylinder 2. Everything else was fine.