Chrysler Pacifica Problems

Check Engine Light Due to Carbon Buildup on Valves on Chrysler Pacifica

Problem Description and Possible Solution

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.

(54 people reported this problem)

Chrysler Pacifica Vehicles With This Problem

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Average mileage: 128,671 (60,000–178,000)
Engines affected: 3.5L V6, 3.8L V6, 4.0L V6
5 model years affected: 2004, 2005, 2006, 2007, more2008
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Viewing 1-17 of 17 comments
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.
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.
My check engine light is on constantly. I have taken the car to 2 dealers, spent a ridiculous amount of money and the problem still exists. They replaced the 02 sensor, cleaned the valves, did a tune up, and several other miscellaneous repairs. The car does not stall or stutter, it runs as smooth as the day I bought it. I would like to have the problem resolved but I refuse to keep giving away money to people who won't or can't fix the problem. You'd think a dealer would employ knowledgeable mechanics.
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
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.
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.
Engine Misfire, cylinder replacements, timing belt and water pump. $3900/ Called Chrysler they said not under warranty and cannot help with resolution.
A couple weeks ago, engine stated giving me problems. Felt like my car wasn't getting fuel and check engine light came on. Computer diag indicated cylinder 5 misfire. Started by using injector cleaner. Problem cleared for 2 days and then returned. Replaced cylinder 5 coil pack. Felt better, but still not quite right. Could smell fuel in the exhaust and could hear light puttering sound. Changed oxygen sensors. Cleared the smell and felt better but still not quite right. Computer diag still indicating cylinder 5 misfire. Decided to replace all 6 spark plugs. When spark plug was pulled, oil started coming out. Opened valve cover and found gasket needed replaced. Also found intake manifold gasket was wearing so replaced both, all 6 spark plugs, all 6 coil packs with new. Ran for test drive and drove perfectly. Drove home 15 miles and ran perfectly. Started engine next morning, problem found again. Computer diag now detecting multiple cylinder misfire, cylinder 5 misfire, took back to shop. While waiting for mechanics to find time to tear her back down, the night shift staff found the headlights are coming on randomly, flashing, flickering. Nobody near the car, keys securely hanging on rack. We still have no official diagnosis and we are unsure if the problems are related.
I bought my "car" (I use the term loosely) about 8 months ago used with 150000 miles on it. Love the thing to death. The Pacifica was and is everything that I wanted and need for my needs with work and home. Within 30 days theI started to have fuel issues with the gage dropping randomly. A month later the pump goes out and now I only have access to 1/2 my tank . I can deal with the pump issue that these cars are known for. After 2 months of that, I end up with a misfire code for #3. The hubby fixes it and we are back to running great, minus the fuel issue. Now, a few months later it comes up with #4misfire. So I go out and replace the spark plugs first. Have the code still but starts to act worse. Car vibrates more and stornger, sounds like a steady thumping throughout the car inside and RPMS drop to almost nothing. Go to have it read again and the code is still there. Next replace all the coils (great idea!!! NOT!!!). Thinking this is going to work and jumping for joy to finally have it fixed (after 5 days without a car) turn the key and BOOM! The effing light is still there. With a sinking feeling I Google the crap out of it and realize that if the same code pops up again, then my previous celebration was premature. Although the RPMS and power were back. I take it to be read one more time with the knowledge that now if it reads misfire again then it is the cams. Lo and behold, what do you know there it is. Misfire in #4. Crap! I can do no more. I am not that knowledgeable on my own car, that by the way has absolutely no repair books or troubleshooting information to refer to without paying over $300, that I now have to take it in to a dealer/mechanic for it to be fixed.
Apperantly when I had the car tore down when fixing it I found a) the oil leak (right into the intake manifold, b) the wrong type of spark plugs, c) wiring harness crumbling, d) cracked and flat gaskets, and finally household screws holding things together.

I love my car. But I can not be spending more money into fixing it than what it is worth. From all that I am reading about the various issues this model is having, I wonder if it is worth the time and resources that I know are going to continue to come up.
If they did not just decide to quit making this model and fix the issues then I believe that there would be more happy clientele.