Pontiac
Bonneville
12

Misfire and/or Check Engine Light Due To Failed Ignition Coil on Pontiac Bonneville

Problem Description and Possible Solution

An ignition coil may fail causing one of the cylinders to misfire. Each of the two banks of cylinders has its own coil assembly. If one ignition coil fails the coil assembly for the corresponding cylinder bank must be replaced.

Problem Data
RepairPal Verified
Average mileage: 108,100 (62,000–151,073)
Engines affected: 3.8L V6, 4.6L V8
3 model years affected: 2000, 2004, 2005
12 people reported this problem
Comments
Viewing 1 - 3 of 3 comments
Hard to start about half of the time, wont get up to speed no where near as fast as it used to, starts shaking bad going down the road, will take probably 2 minutes to get up to 60mph
I check ignition coil cylinder 4-1 has no power
Checkbengine light on.....Would miss or cut out when I'd go up a hill or accelerate too fast.. almost felt like plugs and wires ..they checked those first.. still did it .....replaced 1 coil pack.. ran fine ..a month later did same miss.. replaced 2 nd coil pack.. been going fine for over yr.. started jerking again under heavy load in trunk or going up hill.. no check engine light this time . Ended up being 3 bad mounts on engine .. well the weight of engine rocking when shifting from overdrive to drive on hills was the miss or clunk I felt.. when transmission trying to shift.. my coil packs had check engine light when they were bad.. I have not yet replaced 3 Rd coil pack yet..