Hello all,

I've been having this problem for some time now (since December) but had put it on the back burner for a while to get some front suspension components replaced, but now that that's done it's time to turn my attention back to this. My truck is a 2002 Ram 1500 QC 4x4 with the 4.7L V8 and automatic trans. It has roughly 100K miles on it. When the problem first started out it would sputter on occasion whether at idle or going down the road, sometimes bad enough to make the whole truck shudder or buck while driving at a constant speed or downshifting under acceleration. The check engine light would come on and when I pulled the codes I had the following:

P0300 - Random/multiple cylinder misfire detected (this code would not come up every time but the following 2 did)
P0304 - Cylinder 4 misfire detected
P0308 - Cylinder 8 misfire detected

Now I had just bought the truck used towards the end of last summer and didn't know the history as far as maintenance so I figured I'd start with new plugs. I changed them and found #4 to look almost new with very little wear or discoloration, and the rest were well worn with the center electrodes worn almost flush with the porcelain insulator. None of them were wet at all. All the plugs matched as far as brand and part number so it would be my guess that they were all put in at the same time. While I was changing plugs I also swapped the #4 coil to the #2 cylinder and the #8 coil to the #3 cylinder to see if the misfire would move to cylinders 2 and 3, but it hasn't--cylinders 4 and 8 continued to have the problem. Last night I retrieved even more codes than before:

P0300 - Random/multiple cylinder misfire detected
P0304 - Cylinder 4 misfire detected
P0308 - Cylinder 8 misfire detected
P0442 - Evaporative emission control system leak detected (small leak)
P0455 - Evaporative emission control system leak detected (gross leak)

I was thinking maybe I'll swap injectors around next to see if the problem moves with them, but it looked like a pain in the azz to do so figured I'd check with you guys to see if that's the next logical step or if you had other suggestions. Has anybody else here had this problem before?

Also, one other thing I thought I'd mention - when the truck is cold and I start it up (especially for the first time of the day), I hear a rattle for about the first minute or so of it running. Sounds like a pushrod V8 with lifters that just don't want to pump up but I know there's no pushrods or lifters in there. A friend with a 4.7 Durango told me this is normal - is this true?

Thanks in advance for any and all help.

 

After reading your post. There are a few things that I can think of that it could be, but first you need to do a compression test.

 

im having the SAME exact problem on a car im borrowing right now. cyl 1 misfire. plug looks almost new. im gonna keep an eye on this thread, lemme know if you find the root of the problem, and i will do the same.

 

OK, I was planning on picking up a compression tester but haven't yet, but these things are...???

I appreciate any help I can get, but if you have any ideas I'd like to know what they are before I go tearing into stuff. I don't want to take everything apart to run tests and post my results up here and possibly wait a very long time for somebody that might not even get back to me the same day while my only transportation sits outside in pieces (other than company vehicle that cannot be used for personal use or my Buick GN which will not come out of winter storage for at least another month). I know this may sound like I'm being blunt or rude but believe me it's not intended that way. If I'm going to go looking for something I need to know what it is I'm looking for though. I don't *think* it's a blown head gasket, broken ring, or gouged cylinder wall since I don't have any mixing of fluids going on or any unusual noises or wet spark plugs or puddles on the ground, that's why I'm leaning more towards a problem with fuel delivery to the 2 cylinders in question (#4 & #8) or an electrical problem causing lack of spark or fuel (ECM or wiring harness). The rattling sound when I start it up cold that I mentioned in my previous post has always been present since I've had the truck. If I'm missing something please let me know, and thanks again. I will be picking up that compression tester soon.

 

hey there ,
i have the exact truck and milage and the exact same problem .. i finally fixed mine this weekend , my problems were on cylinder #1 and #3 and min ended up being a bad control circut and had to get a new computer because we werent getting a trigger on it and cylinder #3 ended up being a bad coil.. it runs like a dream now .. hopefully yours inst a computer but id check to make sure you got a trigger on the ones your getting codes on

 

if you do end up needing a new pcm (computer) dont spend $700-900 at the dealership. you can get em online from soloauto for like $200. got one from them for my durango a while back, they were really awesome guys.

 

Now we're getting somewhere...by "trigger" you mean a signal to the coil from the computer, right? What kind of signal am I looking for--is it a 12VDC pulse that could be measured with a good digital voltmeter like a Fluke 16 or does it pulse too quickly for a DVM and require something more sophisticated like an oscilloscope? Was your truck misfiring all the time or was it doing it sporadically like mine seems to be? Just wondering if I'm going to have problems checking for the signal in my driveway if my truck won't act up while sitting there idling. I believe I've already eliminated the possibility of it being any bad coils when I switched the coils around and the problem remained on the same cylinders it started out on. Also, if I remember correctly the connector at each coil had 3 pins--which ones am I to check for the signal on? Thanks for your help...

 

while looking at ALLDATA about this problem, it said to use a stethoscope and listen to the coil for clicking to see if its firing or not

 

Hi Ramit,

You might be dealing with more than one cause of your problem.

My '02 4.7 would rattle like you describe for a few seconds when cold-started. I eventually found that one of the exhaust valve cam followers had been "spit out". I decarboned the motor with Seafoam and reinstalled the follower. Never heard another click since. I've heard that the 4.7's are bad about carbon buildup on the valve stems causing them to stick, therefore the follower can fall out.

As for the clean plugs, the problem sounds electrical in nature. If you are going to try another computer, there are on-line salvage yards where you can get one for under a hundred bucks.

 

Thanks for your insight on the rattling noise. What does a cam follower look like, and where is it supposed to go?

On another note, the other night when I pulled all the DTCs and posted them here I also cleared them, and they haven't come back yet. A few weeks ago I had poured a little bit of Seafoam into the crankcase and a little into the fuel tank then changed the oil shortly thereafter. Maybe it had a positive effect on my problem, maybe not. Won't know for sure until I get a chance to get on it a little like when merging onto a highway or something, since that's when it's more apt to set a code, but right now it's too snowy and slippery for me to put it to that test. I haven't used a vacuum line to pull the Seafoam into the engine yet--I don't know; I guess I'm a little worried about the neighbors b1tching about all the smoke that would ensue...