QuestionI have a 1996 Pontiac Grand Am GT Manual Transmission 2.4L DOHC.
I replaced the water pump about 2 months ago.
One month ago the car stopped working and the mechanic replaced the ignition coil housing. It then worked fine for about a month.
A month later, it broke down again. A 2nd mechanic after this most recent breakdown checked the ignition module, coils, and he said they checked out ok. He replaced the ignition coil housing with a new one and it now runs fine again. Error codes that came up during this visit were:
1) P0304 - Misfire #4 Cylinder
2) P1406 - EGR Pintle Position Malfunction
3) P0420 - Catalytic Efficiency Below Threshold
He checked the old ignition coil housing and didn't see any suspicious deposits on it. He also said the oil sender switch was leaking.
What could be causing these ignition coil housing failures?
AnswerJason
GM was aware of the problem with the coil housings,they issued an updated coil housing to correct missfires,what was happening on the original production housings the composite material used was prone to carbon tracking,the plastic that was used was manufactured with small aluminum particals,though great for heat dissipation they attracted the carbon from the ignition,this in turn caused the spark to follow the carbon to ground instead of firing the spark plug,this caused excessive missfires,GM updated the coil housing with a new material that didnt have any metals impregnated into it,this elliminated the carbon tracking.
ED
