Car Problem Reports

Chrysler Pacifica Check Engine Light Due to Carbon Buildup on Valves

Chrysler Pacifica Problem
24 Reports
Me Too

Model Years Affected: 2004, 2005, 2006, 2007

Engines Affected: 3.5L V6, 3.8L V6, 4.0L V6

Average Mileage: 126,699 mi (60,000 mi - 178,000 mi)


Carbon buildup on the valves may illuminate the Check Engine Light, indicating "Multiple Cylinder Misfires." The combustion chamber must be cleaned of carbon. There are updated valve spring retainers that will help prevent a recurrence.

  • Visitor, , 3.5L V6, 85,000 mi

    I bought this car used last year, shortly after getting it home from the dealer the check engine light came on. The code was p0304, misfire on cylinder 4. I took it back to the dealer who had it checked out several times. within the first 3 months of owning this vehicle it spent 2 months with the dealer..... the dealer gave up and said they cant fix the problem, I later did some reading and found out about the carbon buildup on the valvles that cause them to stick. The solution we have found for this is to use a good quality fuel injector cleaner and then switch to using gas from a manufacturer that includes cleaning agents in the gas, prefereably the premium grade. CHeck engine light has been off since then.

    Flag This
  • Visitor, , 3.5L V6, 155,427 mi

    Engine light comes on and just got a tune up and oil change.

    Flag This
  •  Rookie

    my check engine light is on as well whn they get buildup like that would it cause my car to back fire and hard to start,put in a new fuel pump worked for 2 days and it stopped agian.or what would make my fuel pump burn out so quick

    Flag This
  • Visitor, , 3.5L V6, 60,000 mi

    If I try to maintain a steady speed of between 35 and 45, the car just "stutters". Higher speeds and lower speeds seem ok. My mechanic has cleaned all the cylinders because of the "cylinder misfire" code. He puts some stuff in to clean valves and it's ok for a while then starts again.

    Flag This
  • Visitor, , 3.5L V6

    misfire codes come up change all the coils and still get misfire and engine light blinking

    Flag This
  • Visitor, , 3.5L V6, 65,000 mi

    Engine Misfire, cylinder replacements, timing belt and water pump. $3900/ Called Chrysler they said not under warranty and cannot help with resolution.

    Flag This
  • GOLDENGODDESS, , 3.5L V6, 154,456 mi


    Flag This
  • tonygday, , 3.5L V6, 157,000 mi

    Engine light comes on and usually stays on. the Last car I brought with this same problem, I wasn't able to Pass the emissions Test.

    Flag This
  • Visitor, , 4.0L V6, 167,000 mi

    I had a similar issue reporting on cylinder#3 (I have a $20 Bluetooth code reader from ebay which communicates to my "Torque" Android app to get & clear codes - use it on my Jeep compass too).

    Anyway, I bought one new fuel injector ($75 in Canada) and replaced #3 injector and the shuttering/mis-firing has been gone for a year! Drove the car 1000+ miles to P.E.I and back from Ottawa the week after the change.

    Best 75 bucks I ever spent, it did take a bit of a learning curve to get to the fuel injectors. Whole top of the engine compartment removed, but took my time, cataloged parts and I did it! Felt kinda cool figuring this out on my own!

    Please beware that my issue might not be the same as yours, I am not a mechanic just a tinkerer that got lucky starting with one of the cheaper solutions and it worked.

    Flag This
  • sauerlemon, , 3.5L V6, 140,000 mi

    Still trying to get it fixed.

    Flag This
+ See more reports
Ask a Question