Engine misfire?

Hello,

It sounds like you may have an intake gasket leak when you put the engine back together. Here is a guide to help confirm the problem:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

This guide can help as well

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

Please run down this guide and report back.

Thanks Ken, removed everything again, cleaned everything off, used contact cleaner in the connectors and tightened everything up. Put he intake back on made sure all bolts were tight, and all issues resolved.

Thanks for your response and help

Nice work, we are here to help, please use 2CarPros anytime.

Started with a lost of power and engine rattling shaking. Had the computer read and it stated that it was a Misfire on cylinder seven I took it to the garage and the mechanic said it was some pipe that looked burnt out. I had it replaced but it did not help the problem. next had the engine removed and new seals were put it. all new spark plugs.the pistons and cylinder were inspected and looked fine. fuel injectors were cleaned and all.the engine was put in and the same problem as before. it was running no better.read the computer again and it showed a faulty o2 sensor so replaced all of them, that did not help either .read the computer again and now it reads code P1072. checked the MAF and it seems fine. we are at a lost here any help on where to go next would be great.

take to a garage that can freeze frame and read the sensors, seems like where you took it they did not know what they were doing. also check fuel pressure with a gauge auto parts rent it. then look for a vacuum leak. this can be anything from a basic ignition problem to some thing more serious which seems to have been eliminated. also do a compression check the engine should have never come out to begin with especially since you still have the problem. check plug wire and coil for resistance as well. from what you have written it almost sounds like a home garage where the person wasn't really qualified on what to do.

https://www.2carpros.com/articles/how-to-check-fuel-system-pressure-and-regulator

this guide can help as well

https://www.2carpros.com/articles/engine-misfires-or-runs-rough

These mechanics here are a joke. I forgot to mention that we are living in Iceland and our Dodge was imported.there are no dealerships or garages around us that have a lot of experience with these engines. I am hoping for the best here since money is flying out the window on this. Will put the car in the garage again tomorrow and have them do what you said to do. Also after reading what I can online about this I am seeing a lot of people who state that they cannot start the car even.That is not my problem at all. She starts fine and runs at idle great, but what is noticeable is the shaking or vibrating that is going on and the lost of power when you are driving. I am just mentioning this since you stated to do a fuel pressure test which will be done in the morning. Even if this part is okay would the fuel pressure have anything to do with it or are we ruling out whatever we can at this point?

have them spray choke cleaner around vacuum lines for the leak.

I recently purchased a 2005 Durango after my 2004 Durango limited hemi was totaled. This new one is in excellent shape. Was driving no problems, no codes, no engine trouble. Took it to dealership to recall passenger airbag. I got home filled all fluids, and I had to spray engine down will some coolant that leaked when filling radiator up. We went out to dinner and on way home the truck suddenly started to misfire. This came out of no where. We did a sudden increase in speed to pass a car. I put the scanner on it and it came back with cylinder one misfire. I got into the component check and found not only did cylinder one misfire 42 times, cylinder 6 misfired 2 times and cylinder 8 misfired once. There has been absolutely no problems until I hosed off the engine compartment. Could the harness have gotten wet and just needs to dry out or could something else have happened out of nowhere? Nothing like this has happened until it was at the dealership and they replaced airbag and checked fluids. I did purchase new spark plugs for it and just haven't put them in yet as there was no problems till now. Do I just need to see if it was the harness that got wet or do I need to look further into this?

Misty

Hello,

It very well could have been water getting down into your spark plugs and causing your vehicle misfires. I have included in the diagrams below a troubleshooting flowchart for P0300, which is a generic DTC for random misfires, But it will apply to each cylinder individually as well. Please go through it and let us know what you find out.

Thanks,
Alex
2CarPros

Hey all, a misfire problem that has been haunting me for almost a year. It comes and goes.. The first time was a coil pack fixed the problem. Over the last 8 months or so, it starts missing randomly and stops after a few days. It has gotten really bad over the last few weeks. It kept giving either a cylinder 3 or 4 misfire (5 once as well, i believe). I replaced the spark plugs, and 2 more coil packs, and drove great for about 2 weeks. Now its missing worse and more than ever (before only when warm). The engine light finally came on today, and its reading cylinder 4 AGAIN. This cylinder has a new plug and coil pack. I also re-arranged the injectors over the last few weeks. WHAT is causing this?

When you remove the plug, what does it look like? Is it wet, oil fouled...? Have you checked the crank sensor to make sure it is in good shape as well as the coil wires? You could have a break in the insulation causing the problem. Check them for continunity all the way back to the PCM. While checking, move the wires around to see if they cause a change in resistance.

If all that is good, we need to check compression in that cylender.

Let me know what you find.
Joe

the plug looks fine, as well as the wires/electrical plug that plugs into the coil pack. I have been thinking about the crank sensor as well, but I believe that will trip its own code, won't it? Whenever it starts misfiring, it trips the same cylinder number for a few days and randomly changes to another. I was a tech for GM 6 years ago, but did more steering/suspension/brakes than other repairs so I have a good knowledge of autos but am just a little rusty on the self-diagnosis end of it. I miss all the special equipment the dealer suppied!

Remove the injector and rail and check for dirt
very common
Never seen a random misfire that comes and go caused by a bad crank sensor

When I swapped the injectors between cylinders a couple weeks ago there was no dirt or grime past the o-rings on any of them. They looked good/clean.

Up until this weeks episode, it only missfired when the engine was warm, and got significantly worse if I was driving around town for an extended period of time. After I replaced the spark plugs (that were only 6 months old)it ran like new. Now after 2 weeks of it driving fine, it has started acting up again, but now its missing from the second I crank it up in the morning. It makes me think that it was coincidence that it stopped when I changed the plugs.. because of the history of this problem over the last 8 months (only missfires for a few days then goes away as randomly as it started). But now that it is coming and going every few weeks instead of every few months, it makes me think that I have a part/sensor on its last leg thats either about to or already has completely burnt out or failed. During the older episodes, it acted up more at half to full throttle and was fine at lower rpm's... now any throttle, unless absolutly babying it, makes it act up. And if it helps, after I ran the AC for 10 min the other day the misfire got almost twice as bad even after I turned the AC off and has stayed this way.

I have too much pride to take it to a shop, and I am very mechanically inclined, but this issue has me stumped.

SO.. The plugs are new/look good, there is a new coil pack on the current problem cylinder, the injectors looked good and were swapped around, and I've owned this truck for over 2 years of its 5 year life and put over half the miles on it and have taken good care of it during this time.

Anyone have any personal experiences with this SUV/motor that might stand out in this situation? Or any other ideas?

i have an 03 durngo with the 5.9 and im having random misfires on the entire right bank. replaced all the typical ignition parts and even pulled and cleaned the fuel rail... still happening. not too noticible at idle but gets bad when i get on it. typically barely existant until it warms up just a little bit. running fuel system cleaner through helps but as soon as that tank of fuel is gone and replaced, the problem returns

When you replaced the ignition components, did you also replace the coils? And did you have a check engine light on? If so, did you have the computer scanned?

If you've eliminated the ignition system as a possible cause, then the fuel system is the next target for diagnosis. Begin with the fuel filter. A clogged filter will allow the engine to run at idle but when you accelerate it'll bog the engine down because it can't flow enough fuel to supply the load. But if you're sure that only the right bank is misfiring, then it'll have to be something on that bank causing the problems. I'd believe it would be the injectors are clogged or the wiring for that side is faulty.

77,000 miles 360 v8
At 40-45 it starts missing shaking bad above that it is fine. I put plugs in still does it. Someone told me it was the tourgue converter lock up switch?????

The torque converter would not lock up during acceleration, only at your top gear at an even pace (the torque converter drops your engine rpm's at higher speed to increase fuel economy and decrease the demand on your engine) so probably not. I don't have a good guess on this one yet, but I'm working on it.

the guy told me the 4wd switch stoped working
as soon as that stoped working thats when it started doing it. when it shifted into high gear
around 40-45 that's when it starts doing it.

we had a similar problem with ours
take it to a free inspection tranny place and they can narow it down but it may have something to do with the clutch packs of your higher gear but more likely its the cylinoid and governor ones a switch ones a sensor and it made ours better

1 3 5 7 cylinder are mis firing. my check engine light came on and this is what message it was. now i have done a full tune up new plugs, wires, and cap. when i took out the plugs in the right side they where all black and every once inawhile i will get a cloud of black smoke to come out. what else can i do. could it be a egr vlv.

Misfires can be caused by worn or fouled spark plugs, a weak spark (weak coil, bad spark plug wire), loss of compression, vacuum leaks, anything that causes an unusually lean fuel mixture (lean misfire), an EGR valve that is stuck open, dirty fuel injectors, low fuel pressure, or even bad fuel.

I have the 4.7. 2wd I blew a headgasket and replaced it I did a coolant pressure test and it holds 16psi for 20mins or more it doesnt leak down. I have a misfire code from every cylinder and I put new plugs the driver side is lean passenger is rich also when the engine gets to operating temperature it shuts down will not idle by itself.

is there any codes???? what are the numbers??

check fuel pressure

Roy

Turns out the timing was off one tooth on the passenger cam I set it while it was on a jack and the car was crooked

My truck was acting as if I was running out of gas. I have had no engine lights on, but at a light, I would have to put it in neutral and give it gas because I was afraid it would die. My friend took a look at it and around 4000rpms, you could hear a hard rattle. He changed all the spark plugs (Champion) today and after he started it back up, immediately, the check engine light started to flash and my friend said it was still missing and to kill it. He thought maybe a wire was crossed. He crossed them and it backfired and he put them back. Codes P0300, P0306, P308 came on and won't clear. Please help, I'm a single Mom with limited funds. The only reason my friend offered to help is the local mechanic said it would be $100 to change the spark plugs and then we could go from there. Thanks so much.

Hi ChristiNate, Welcome to 2carpros and Ty for the donation

P0300 random misfires normally caused by vacuum leaks and contaminated fuel

P0306/P0308 -check these cylinders sparkplugs/compression and injector

Thanks, rasmataz, for replying so quickly. But, unfortunatley, we do know what the codes mean. We just need to know where to start from this point. Also, I haven't had any check engine lights on or codes before we changed the spark plugs. Thanks.

Check the sparkplugs gap and also if its the correct type plug-make sure you have a tight connection between the plug and the wire

P0300 random misfires =normally caused by vacuum leaks and contaminated fuel

P0306/P0308 this a probable causes here=check these cylinders sparkplugs/compression and injector

He had it at .040 and I will relay this info to him in the morning.
I just don't understand all the codes flying out now after the new spark plugs went in beacuse I had no engine light on before????

I have been doing google diagnostics. Do you think it could be the plenum gasket?

i had a mechanic replace my motor with a used motor, he has finished the job but states the cylinder is misfiring when you start the vehicle. what could cause this problem.

Hi:
It could be many things. Spark plug, coil, wire, incorrect placement of plug wires, weak fuel pump, injector, fuel pump pressure, low compression...

Has he checked the computer for codes?

WILL NOT IDLE. EXAUST SMELLS LIKE GAS. Cylinders 1-2-3-4 are not firing. Cylinders 5-6-7-8 work. I switched the coil packs front to back, same thing. No check engine light but it runs like crap.

Did you check and/or switch the spark plugs? and plug wires?

Head Gaskets are 1 month old as well as the spark plugs. There are no wires, the coil packs connect directly to the spark plugs. When I checked the spark plugs, cylinders 1-4 are wet and smell like gas. Cylinders 5-8 are soot covered.

Perform spark check on coil packs/stick coils and replace all spark plugs.
Possible faulty coils/stick coils on cyl 1-4.
After check post findings for more diag.

stick coils check out good on all eight cylinders. Is it possible that the PCM is bad? Or maybe injectors 1-4 are stuck open? Also I had a timing chain set installed after the problem started, but there in no change in the way the truck runs.

I have a 2002 durango 4.7 with the same exact problem and I did a timming chains on it and new plugs and still missing really bad. did you get yours fixed

The pcm does control spark, but it is odd that you'd lose that number of cylinders.
Have you tried putting a scanner on it? I have seen before that a check engine light is not on but there were still codes (either pcm signal to dash is damaged, or engine light is burnt/faulty).
It's been a while since I worked on a hemi, are cyl 1-4 on the driver side?

Also test power to coils with engine cranking.
Unplug all coils and attached battey charger/tender.
Test power to one of each coil connector... attach positive lead of volt meter to coil and negative lead of meter to chassis ground (I can't remember the color of the wire for the power to the coil, so you'll have to test for power to both wires)...test known good coil connector (from cyl that fire 5-8 to know the correct power wire) and then test bad connector (from cyl that do not fire 1-4). You should see a 12-14v power to them.
If power is good then suspect faulty coil/stick coil.
If no power, check fuses throughly (visual and ohm check). If no bad fuses then possible faulty pcm/ecu.
After tests report findings back. (include wire colors tested)