Mis-Fire

[nicmartim]

Hey all, quick easy question. Wife came home from the grocery store this afternoon in our 2002 4.0 Mountaineer and reported an illuminated CEL. Engine sounded kinda like a sewing machine (clackity-clackity). I pulled codes w/ my AutoEnginunity and came up w/ P0300, P0305, and P0316. All point to #5 five misfiring, righting itself and misfiring again.

My question is would an active misfire cause the engine to sound off?

It wasnt jerking when she got home although she did report it did kind of shake at idle at the traffic light on her way home. Pulled the LT sided plugs and they are well worn, so I'll be replacing them, possibly plug wires (133K on them), clearing the codes and trying again. Anything else to check before I move onto the injectors and then deeper down the rabbit hole?

 

[nicmartim]

Add'l Info

Also, this thing has never used a drop of oil or coolant, has ALWAYS run great. I am not too concerned about the misfire nor its codes. I am most worried about the clacking noise it was making while idling in the garage. Any ideas?? Thanks all!

 

[rwt101]

It could be a rocker loose on the cam.
Bob T

 

[Number4]

Check the OHMS resistance on all the wires, they should all be close. If #5 is way off, then It's the wire, otherwise you can probably skip them.

I don't see a misfire (especially on one cylinder) causing any noise.

Does the engine make any rattling or grinding noise at cold start up?

How many miles on it?

 

[Tech By Trade]

Lemme guess. Runs alright at high RPM, but sounds like a diesel at idle? Pull the lower oil pan and let us know how much plastic is sitting in it.

 

[nicmartim]

New plugs/wires and I fired it up this afternoon. Purrs like a kitten. Gotta put some di-electric grease in the boots and get some miles on it, but encouraged so far. I have no idea why it was rattling when mis-firing. It has NEVER given us any problems, always sounded great at idle all the way to 4500 rpm. I'll get some miles on it starting tomorrow and hope for the best.

 

[nicmartim]

Running

Hey all, got it running, but runs a little rough. I found the below vacuum solenoid but the bottom hose seems to be missing. Anyone tell me where to find the bottom hose. I'm sure there should be a hose on it as the bottom portion of the nipple is clean. The top hose was lodged between the heater hose on the left of the image and the actual solenoid. Replaced it, now just have to find where the bottom hose went.

This solenoid is on the passenger side, just under the intake tube and the bottom outlet/inlet is 90 degrees toward the passenger fender. Thanks!

 

[Bobmbx]

Thats your heater control valve acutator. Only one hose, and your picture shows it in its correct configuration. I can't explain the clean tip. Maybe you cleaned it off with your fingers while fiddling with it?

 

[fritz24]

One way to confirm the misfire on cylinder#5 is to pull the wire while engine is running. If it has the same idle when plugged and unplugged than it is confirmed misfire. So you have to confirm again if you're missing spark or fuel. Remove the spark plug to see if it soaked with fuel or not. If it is dry then you have fuel delivery issue. Mine was 06 and it did the same as yours, running crap at idle. Changed wire and plug but nothing. I did put stp multipurpose cleaner two times in my gas tank and replaced the filter afterwads. These will clean and remove any water vapor in your fuel line. Now i dont have any idle issues. Nway there is no hose on the bottom of the heater valve
Resistance on all wires differ from each other since wires have different length x 7k ohms. Replacing them is necessary.

 

[Tech By Trade]

Another option is to swap 5 and the one across (cant remember the number) from it and see if the misfire moves with it. Wasted spark system both sides fire at the same time. They also like to starve the back 2 cylinders when the fuel filter plugs which will cause misfires.

 

[Number4]

Go into the live data stream on a scan tool and watch what it's doing. Here's a good article on it.
http://www.motor.com/article.asp?article_ID=1794

 

[nicmartim]

Ok, the misfire is gone. Plugs and wires took care of that. I am still getting the clacking tho. It makes noise at idle when warm and rattles when going down the highway but then stops right after it shifts, clacking away again when RPMs climb. I listened to lots of YouTube videos where people had known timing chain issues and mine does not sound quite as harsh as those. Mine is more of a softer clacking sound, in tune w/ the RPMs. I may take the accessory belt off it and see if it changes at all, but i am pessimistic at this point. It is definitively just the front of the engine so replacement shouldn't be quite as bad.

Also, I am finding a fair amount of oil coming out of the right valve cover area suddenly. The misfire, clacking and oil all started at the same time. Kinda of an odd cluster of symptoms. Does anyone else think maybe a hydraulic lash adjuster pooped out on #5 ?

 

[nicmartim]

Thats your heater control valve acutator. Only one hose, and your picture shows it in its correct configuration. I can't explain the clean tip. Maybe you cleaned it off with your fingers while fiddling with it?

Also, thanks Bob!

 

[nicmartim]

After much discussion and reading I am leaning toward my noise not being the timing chains (hopefully). At initial startup it purrs like it always has. Only once it's been driven a bit does it start to clack. Possible causes right now include anything driven by the accessory drive belt, lash adjuster(s), harmonic balancer, or cam bearing. Anything else I should be considering? Again, thanks to everyone for the help so far.