Has anyone encountered a problem with an intermittent cylinder misfire? My 2000 Lesabre started yesterday morning, began running rough and the check engine light started to flash. Then after 10 minutes of driving the light stayed on steadily and the rough running stopped. This morning the same situation happened again so I got a code reader that indicated #6 cylinder was misfiring. I erased the code, restarted the engine to confirm the problem but the engine ran fine and the code reader detected no malfunction. P.S. I have a 1996 Lesabre with the same problem. Help!

 

It's look like a defective coil. Often moisture cause trouble, when
your car get hot and the coil goes dry the coil stop sparking on the
body and the motor seem to run better.



In most case it's just one coil, it can be also the coil plate under the 3 coil.

 

check for vacume leaks when cold intake is composite and haeds are not thay have diffrent thermal expansion rates causing gaskets to split when the motor warms the rubber o-ring part of the gaket expands and presto no more miss.