Code po300 2007 buick lucerne cxl 3.8 v6 help.

[07cxl]

Been getting this code only now for a month. The problem is still here and I'm lost as to what to fix next..really don't want to go to another shop, did that and was charged $1,500 only for the problem to still be here. Was told from the shop that my "engine were melted and that I needed a new engine wire harness but they could not find one so the only option is for them to go wire by wire and that's another 9 hrs of labor" but anyway I already changed spark plugs and wires as well as 02 sensor upstream only though and ignition control module. Car is rough and idles bad, barely goes over 60 with the pedal to the floor.. thinking something electrical . Just yesterday it drained my battery and is now dead. I'm leaning towards just bringing it the buick dealer shop.. any suggestions would be helpful. TIA

 

[century61]

Did they point out the spot where the wiring harness was melted?

Other than that, The 3800 is notorious for intake manifold gaskets. They are not real hard to do. Do you have access to a scanner?

 

[2007LucerneCXL]

Little hard on a general code and without knowing how well the shop did on troubleshooting it a guess. Coils might be something to check prior to bringing it to the dealer there a few YouTube on it.

But without a professional scanner it's parts or area guessing along with the harness that may be the problem.

 

[07cxl]

Did they point out the spot where the wiring harness was melted?

Other than that, The 3800 is notorious for intake manifold gaskets. They are not real hard to do. Do you have access to a scanner?

Nope never showed me one burnt wire. Never smelled burnt. Just getting it scanned at autozone and same code

 

[century61]

Nope never showed me one burnt wire. Never smelled burnt. Just getting it scanned at autozone and same code

That is a general misfire code = P0300 .

Take a good look around your intake manifold gaskets. See if you see anything weird. I have seen people use a propane torch (unlit) and run it around the intake and note any rpm change. This could be fuel related (running lean/rich) or electrical. How is your coolant? Do you have to fill it often?

 

[Mad_Coachman]

Bad coil(s) can take out an ICM. What brand was the ICM?

 

[07cxl]

That is a general misfire code = P0300 .

Take a good look around your intake manifold gaskets. See if you see anything weird. I have seen people use a propane torch (unlit) and run it around the intake and note any rpm change. This could be fuel related (running lean/rich) or electrical. How is your coolant? Do you have to fill it often?

Yes! Gas is going like water but did not see any leak but can smell a hint of gas here and there

 

[2007LucerneCXL]

What is the mileage on the vehicle? How old is the battery? What did the shop actually do for $1500.00?

Has the rear seat fuse box been checked for burnt or melted plastic especially around the fuel pump relays and fuses?

Gas smells, where do you smell them, engine fuel rails, under the hood, drivers door area or by the rear of the vehicle?

 

[century61]

Yes! Gas is going like water but did not see any leak but can smell a hint of gas here and there

Just because its easy, Remove the vacuum line from your gas pressure regulator. Inspect the vacuum line and where it connects to the regulator for gas. If you see / smell gas then replace the gas regulator.

Your regulator keeps / adjusts the pressure of the gas in your fuel rail. When these go bad your injectors will get incorrect pressure or no pressure. Its a quick check.

Do the simple checks first.

 

[2007LucerneCXL]

Are you referring to the EVAP #5?