Replace coil packs or not???

[jlcljayne]

I have an intermittent stumble on my 97 lesabre that is pronounced in drive, especially at a stop sign.

I have new plugs, wires and air filter. I have a new check engine code informing me of a cylinder #2 misfire. I tested my coil packs and here are the results:

Cylinders 2,5 6.06 ohms
Cylinders 1,4 6.59 ohms
Cylinders 3,6 6.35 ohms

Autozone service site says they should be between 5,000-8,000.

It seems that they are fine but I tested a new one from autozone and it registered 9.11. My car has 170k and they may be the original coil packs as they still indicated the cylinder #'s on the top.

Any thoughts on my cylinder misfire and engine stumble?

UPDATE!!!

About 3 months ago I did a minor tune-up with Bosch Platinum plugs and wires..car ran great. After reading various posts I decided to change the plugs to AC Delco just in case all ya'll were right....yep! Car runs better than ever.

[polaris1026]

Originally Posted by jlcljayne

I have an intermittent stumble on my 97 lesabre that is pronounced in drive, especially at a stop sign.

I have new plugs, wires and air filter. I have a new check engine code informing me of a cylinder #2 misfire. I tested my coil packs and here are the results:

Cylinders 2,5 6.06 ohms
Cylinders 1,4 6.59 ohms
Cylinders 3,6 6.35 ohms

Autozone service site says they should be between 5,000-8,000.

It seems that they are fine but I tested a new one from autozone and it registered 9.11. My car has 170k and they may be the original coil packs as they still indicated the cylinder #'s on the top.

Any thoughts on my cylinder misfire and engine stumble?

I had the same problem on my 1989 3800 motor LeSabre. I replaced both the coil pack and the ignition module under it. Junk yard is a way to go on this both together from GM are not cheap.

[HotZ28]

Remember, all you are testing is resistance, not voltage output. Big difference! I have tested coils that measure resistance within range of specification, however, the output voltage was low. When in doubt, replace them. You can buy new ones for around 20 bucks each at Advanced; I don't know what AutoZone gets.

[Hapynzap]

yeah I'd say replace the coil packs too.

btw - have you replaced your 02 sensor and PCV lately?

[jlcljayne]

Originally Posted by Hapynzap

yeah I'd say replace the coil packs too.

btw - have you replaced your 02 sensor and PCV lately?

I have had the car for about 9 months and have never replaced either. I suppose replacing the pcv is a good idea...wouldn't the 02 sensor give me a different code than #2 cylinder misfire? I hate spending money here or there without knowing for sure it will fix my problem.

[Hapynzap]

Well they are both maintenance items. So then you have no idea if the O2 sensor has ever been changed. Best to know IMO by putting a new one in. Can't hurt.

[HotZ28]

Rarely will you ever get a code on a poorly operating 02 sensor; they have to be nearly nonfunctional before you do. If you should, it will indicate a misfire on each bank (group of cylinders in line), not just one. If you want to replace it, use AC Delco brand. For some reason, Bosch does not work too well on the Buick engines.

Have you pulled the #2 plug yet to see how it is burning compared to the others? If not, do so and take a long hard look at the ceramic insulator for any cracks. If everything checks ok, buy one coil assembly and replace the one for that cylinder first. I used the Advanced Auto coils before I purchased the MSD brand for twice the cost. There could be a slight performance gain with MSD, however I never had any problems with the ones I used from Advanced. Again, they are only 20-22 bucks each!!

[GringoPete]

where is the coil pack and does anyone know how to change it? is it easy?

I have a '98