Misfire and rough idle [Archive] - Dodge Charger Forums

: Misfire and rough idle


polarbear18w
07-07-2011, 08:08 AM
Hey guys, I have a 2006 Charger SXT 3.5L HO and recently I have gotten a code for Cylinder 5 misfire (P0305) and now it is starting to idle kind of rough and even shake or shutter after I come to a stop at an intersection. I changed the spark plugs (#5 was more worn than the rest) and swapped coil pack 1 with 5 (since 1 is much easier to get to in case it was the issue). Well after the spark plug change and coil swap the misfire on cylinder 5 is still there, so I know it was not the spark plug or the coil pack. I have run fuel system cleaner several times recently and even tried premium fuel and it is still running rough and shaking at idle after I come to a stop. Sometimes I even hear a knocking noise with the shaking. I am thinking I am going to have to take it in and have it looked at since I have run out of ideas. Has anyone else had anything like this happen? and if so what was the cause? any information would be greatly appreciated, thanks!

Razorback-Rob
07-07-2011, 08:27 AM
Hey polarbear18w,

I had the exact same problem. I have the exact car as you (06 Charger SXT 3.5 H.O.) The car went to the shop 4 times. At first they cleaned the carbon out of the engine. Next they had to replace all of the Valve-springs (which is a recall on the 06 charger). The problem kept arising after each visit. Finally on the list (they know from the beginning) that an exhaust valve on that cylinder (code read by computer) is actually sticking. So what happens is the combustion happens in the cylinder, but the exhaust valve sticks and causes the car to shake violently and almost stall. After this repair was done, the car ran great. Another problem I have come across was the car running rough and shaking with a code on, which was actually the EGR valve. I bought the part for around $90 and replaced myself (need to reach way in there over the tranny). But the car is running great now, haven't had the problem come back in half a year already.

Hope that helps!


Rob

polarbear18w
07-07-2011, 08:42 AM
Thanks for the quick reply. At least there is hope, but it sounds expensive to replace the valve springs and exhuast valve. From all my searching, I had seen that it could be carbon buildup in that cylinder causing the exhaust valve to stick hence the shaking, and that a vacuum leak in the EGR could cause the car to run rough. Good to know that the EGR can be done easily, but I guess I will have to take it in and get cylinder 5 looked at before it gets any worse.

Thanks,

Paul

Razorback-Rob
07-07-2011, 08:47 AM
Good luck! I'm sure after the problems I had with mine that you will need to replace that exhaust valve. Seems to be a factory issue. After the engine gunk is cleaned out the car runs amazing though!

polarbear18w
07-07-2011, 10:34 AM
Was yours covered under warranty? how much should I expect it to cost? and what have you been able to do to keep it from happening again?

Razorback-Rob
07-07-2011, 02:14 PM
Mine was covered under power-train warranty. The car was in the shop for over a day because the engine needs to be torn apart to replace the valve. The EGR valve was not covered though. I think after you have the part changed, run your tank low and then fill up with premium gasoline to clean up the carbon, I found that helped a lot after I had it fixed. It's still running strong with no problems.

MoparPhoenix
07-09-2011, 04:06 PM
How many miles do you guys have on your cars? I have an 06 3.5L w/ 90K miles and have never had this problem...sounds scary tho. Do you guys use engine cleaners/ lubricants like zMax?

polarbear18w
07-11-2011, 09:20 AM
I only have 58k miles on my 06 3.5L. I have not heard of zMax but I do put fuel system cleaner in at every oil change (either Lucas Oil or Seafoam). It started last winter and I took it to a shop for the misfire and they treated it with Seafoam and that worked until recently it came back. They said it was carbon buildup in that cylinder causing the misfire.

polarbear18w
07-18-2011, 03:53 PM
Hey guys, quick update... So I took it to a shop that my friend recommended (the guy there has had Chargers and worked on them before) but he said he has never seen anything like this before. So then I took it to the shop I normally go to and they said that if it is the valve springs or exhaust valve that they would not do it. Looks like no one wants to work on this issue and I am going to have to take it to the dealership this week. Anyone else have any last ideas before I take it to the dealership? I am going to call the one by my work tomorrow to talk to someone about it.

Thanks,
Paul

Razorback-Rob
07-18-2011, 04:29 PM
Hey the Valve-Springs are an actual factory recall, so they will be covered under warranty. My car only had 40k miles when this was all changed. As for the Valve sticking it will also be covered under powertrain, as long as you still have warranty left!

Good luck,

Rob

polarbear18w
07-18-2011, 04:38 PM
I am not the original owner so even though I only have about 58k I do not think I am covered, plus I think I may be past the 5 year mark as well. I guess when I call the dealer tomorrow I can ask them if my car still has a warranty or not. I did not buy it from a dealer so I am assuming not, but will let you know if somehow I am still covered and able to get this done under warranty. Heres hoping it is...

polarbear18w
07-20-2011, 11:56 AM
Well, I called the Dodge Dealer here this morning and they said that there is a service bulletin but no recall on the 3.5L engine. However, they also said that it is only covered under warranty for 3 years/36,000miles. So I asked them how much it would cost and what would be done for that cost. They said it would be $600 +tax and they would had to take the cylinder heads off and would clean the cylinders and rotate the valves, then install new seals and put it back together and do a compression test. So they are not going to replace the valve springs or the exhast valves. Great, so it sounds like all they are going to do is clean it out the hard way so they can charge me more. I guess the upside is that if they find anything wrong with the valve springs or exhaust valves they have it open and could replace them if needed.

So now I need to decide what to do. Pay the money and have them clean it out, not know if it is a permanent fix or not...great.

BURTON
07-26-2011, 07:09 PM
Well, I called the Dodge Dealer here this morning and they said that there is a service bulletin but no recall on the 3.5L engine. However, they also said that it is only covered under warranty for 3 years/36,000miles. So I asked them how much it would cost and what would be done for that cost. They said it would be $600 +tax and they would had to take the cylinder heads off and would clean the cylinders and rotate the valves, then install new seals and put it back together and do a compression test. So they are not going to replace the valve springs or the exhast valves. Great, so it sounds like all they are going to do is clean it out the hard way so they can charge me more. I guess the upside is that if they find anything wrong with the valve springs or exhaust valves they have it open and could replace them if needed.

So now I need to decide what to do. Pay the money and have them clean it out, not know if it is a permanent fix or not...great.

Bear if the dealer does the work and it does not fix it they are the hook to redo it.

R1guy777
08-03-2011, 05:03 PM
I have the same problem on my 08 Charger, cylinder 3 misfire, the light in now gone, I hope it does not come back.

polarbear18w
08-04-2011, 10:10 AM
When mine first happened the light came on and then went off a couple days later, but eventually came back on. Hopefully your light stays off and the misfire does not come back.

My Charger is going in on Monday to have the carbon cleaned out of the engine and checked out to see if there is anything else that could be causing this. I will post an update when I get the car back from the shop.

Paul

R1guy777
08-04-2011, 05:43 PM
Is this procedure covered under warranty?
"My Charger is going in on Monday to have the carbon cleaned out of the engine and checked out to see if there is anything else that could be causing this. I will post an update when I get the car back from the shop."

polarbear18w
08-04-2011, 08:28 PM
The dealer told me it is Only cover for 3years/36,000 miles and since mine is an 06 I am not covered. Hopefully you are still.

vinny469
08-10-2011, 11:19 PM
I have an 06 SXT 3.5 and it would almost stall when I came to a stop, mostly when it was raining. A $5.00 can of throttle body cleaner resolved the problem.

I removed the air intake hose that's connected to the air filter box to get to the throttle body and cleaned the butterfly and especially the sides around the butterfly with the cleaner and an old toothbrush. Once all the gunk was cleaned there was now the correct amount of air flow through the slightly open butterfly during closed throttle position to allow it to idle normally. Took 10 minutes and 5bucks to resolved my problem.

polarbear18w
08-30-2011, 01:33 PM
UPDATE: So it appears that the service bulletin to clean the carbon from the engine does not work. Got my Charger back and the misfire came back after a few hundred miles. Seems that the carbon causing the misfire is building up on the exhaust valves causing the exhaust springs to stick so the exhaust valves on that cylinder need to be replaced. No amount of cleaning without taking the engine apart is going to clean the exhaust valves completely (because most everything will ignite in the chamber and not make it to the exhaust valve stem)...so, I was quoted a valve job would cost $1500-2000.