Harmonic Balance 2007 Buick Lucerne 3800 series 3
 

Hello: Car was running fine but balancer was coming apart... Got a replacement from Napa.. Would not start... Got another replacement from Napa.. Started this time but dead miss on one cylinder, bad odor like too much fuel, and would hardly keep running... Should I bite the bullet and get a genuine GM part new?

Mike:confused:

Have a look at the Crank position sensor, wires, as well as the ring on the back of the balancer to make sure everything is the same.

I would also be curious if the car will start if you put the old unit back on, and if it runs right. Hopefully that would give you an idea where to start looking as well.

Also, if the series 3 is setup like the series 2, I would also doublecheck all of the wires on that too, because it would be right in the area, and I also think there is an engine ground in there somewhere too.

Hello: I checked the plug on the crank sensor and all the terminals are bright and shiny...Got a HB ordered from the Buick dealer and should have it in the morning.. Going with genuine GM ... I just wonder if there is a difference between series 3 engines.... I know there is no adjustment on the crank sensor on this series 3.. I wonder if Napa is trying to cover one two and three series with the same HB...And if there is a difference...Mike

Harmonic balancer problem
 

Hello: I went to the Buick dealership and bought genuine GM for almost 300 bucks with tax and the engine fired as soon as I touched the key.. Ran really nicely....The guys at Napa said their HB was NOT the problem but I had two of them from Napa prior to the genuine GM.. One from Napa would not start the engine at all, the other would run it but barely and miss on one cylinder, wrong fuel mixture(smell) and would hardly keep running....I do not know what the problem with the Napa stuff is but I know it would not work on my 2007 Lucerne 3800 series 3...

GM part number 12563265

Napa part number 6003646

Mike

That's weird. I cross examined both part #'s from a 2005 3.8 to your 2007 3.8 and the part #'s match.

Only thing I can think of is the exciter ring was installed wrong.

I for one would give the OP credit for proper installation as he had no problems with the GM unit and would look to NAPA as the problem with their electrical parts. Been a long time since I've used NAPA for electrical, but back in the old days their Echelin brand of electrical was well known as a POS.

Issue here is, this is not an electrical part, its just a counter balance with a timed ring that interrupts a hall effect sensor.

That being said I would still give the OP the benefit of the doubt as to proper installation and would look to the manufacturer/sourcer.

2004 Bonne SLE
1971 Chevelle SS