Odd shudder/stumble

A

AndyT

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So tonight I was driving on the highway, in stop and go traffic, and noticed this weird shudder feeling around 35. I thought it was maybe just the right speed for the TC to lock up, or whatever, and thought nothing of it. It then started doing it more often, like when giving it gas. It almost felt like a tranny slip. You had to keep your foot into the gas, and it would stop the shudder and be fine. Then it started being almost constant. I pulled over, and saw the PCV was popped out of the rear of the valve cover. I put it back in place, and off I went. That didnt do the trick and its still happening. I stuck my head under the hood, and you can her like this, not sure how to describe it. Almost like a premature ignition? You can hear, what I considered a random firing of the plugs. Sounds like a mini explosion, idk. No lights, or messages displayed. Just finished the valve cover gaskets a few days ago, and no issues until today. I did fill it up with Shell 93 this morning.
 
Mark 8s sound like sewing machines when they're running right. With no CEL I'd say test your Fuel Pressure, and have the gauge sticking out from under Hood on a test drive, check your pressures while putting a load on it

Sounds like what my 93s did before the pump failed
 
Fuel pump.... awesome! It was extremely low before I filled it up too. Guess that's a possibility. I gotta get some cash together, and ship it over to the Ford dealership and have them look into it.
 
Sounds like torque converter shudder! NAPA carries a 2 ounce solution in a red tube, ask for it by name "Dr. Tranny-insta-shudder-fix, worked great on a few of the vehicles I used them on.
 
I was going to mention Dr. Tranny for shudder but wasn't sure that's what you were experiencing. That stuff is magic in a tube!! I put in a single tube a little over a year ago and it hasn't returned.
 
I just did a tranny flush and filter about ~5,000 miles ago. No issues until yesterday. I'm still confused as to where its coming from (engine, or tranny). It seems to shift fine, like 1-2, then thats when it starts happening. I may try that Dr. Tranny stuff and see what happens. When I saw that PCV popped out, I figured it was just a vacuum issue, but I guess not.
 
I feel like its a misfire. It does it sitting still now, in park. I noticed that when putting everything back together that the safety lock clips on the plugs for the coils, were broken off. My dad attempted to "help" me pull everything apart, and this is what happens. So, maybe one of the plugs just backed off a coil. Easy fix, for now anyway. The car isnt here right now, so I'll check a little bit later.
 
Checked all the coils, all looked alright. It is 100% not in the tranny, because it does it all the time now. I'm really not sure about this one. Maybe somethings up with the spark plugs? I gapped them all correctly, so I'm not sure what the problem could be? It sounds almost like its backfiring maybe? You can hear like this "pat pat pat" noise under the hood, then the same thing, just a little higher pitch toward the nose of the car? Not sure what the hell the problem could be. What should I check next? I'm at my moms in RI for Easter weekend, and I need to get me and my sister back home to MA by Sunday night. Wonderful....
 
3rd cat could possibly be stopping up. I doubt it's the trans either. MAF might need to be cleaned, fuel filter might need to be changed but doesn't sound like what you describe. All I can do is guess.
 
Thanks for the input Terry. Fuel filter was done around 6K ago. Air filter (K&N) was re-oiled a few weeks ago. Maybe the MAF picked up some of that oil? The cat(s) may in fact be an issue because when I stomp on it, I get the sulfer smell, but its been like that since I've bought it.
 
The smell from what i've heard is the 3rd cat. Alot of g2's that still have it get the stink @ wot. I'd go pick up some CRC QD electronic cleaner(?). It's cheaper and works the same as maf cleaner . About four bucks and change for a 11oz can at wally world. Chances are the oil from the filter coated the maf wires thus making it do funny things. I'd try that first.
 
Yea, I'll head outside and check that right now. At least start eliminating the easy stuff.

Checked the MAF. Doesn't look dirty at all. No visible residue on the housing, or on the wires. Trying to think of other things that could have become unplugged after doing the valve cover gaskets.... It ran fine after doing the gaskets, and ran fine after I put gas in it. I didnt notice it until yesterday when we got stuck in traffic on the highway.
 
So, cleaned the MAF. No difference. I'm going to go with the clogged cat theory. How would I go about confirming that, without cutting it off?
 
Temperature before and after the cat. Get a temp gun and check.

No CEL? I would be more inclined to go to where you were last. I had a Cougar do this after I did plugs and wires and found 4 months later it was bad plugs. OBD1 car so no CEL just a misfire going on and poor performance.
 
Well, tonight going to the grocery store, I noticed the SES light didnt come on with the rest in the message center with the key on light check. Therefore, I went to AutoZone and had them scan it, and it came back with a Cyl 2 misfire and P2C49, whatever the hell that is. So, I'm going to pull the cyl 2 plug out and check everything over under that coil. Heres a really stupid question. If I'm facing the engine, where is cyl 2? Left or right side, how far back? I'm not familer with these engines whatsoever haha. Never mind, pass side, 2nd coil hahaha. And anyone have an idea about that P2C49? I just logged into AllData and typed in that code, and it didnt come back with anything.
 
Thanks haha. I'll check that out tomorrow. Pull the coil, check the boot, and spring. Pull the plug, and check the gap. Then not sure when none of that fixes it. Maybe try a new plug, then coil?
 
I told you start the car up and lift the coils off one at a time and listen for the arc to jump to each plug you can easily hear it, if all 8 coils are firing you need to figure what plug is junk, if you don't hear one of the coils arcing then you found your bad coil.
 
Yeah, I'll try that later on today. Hopefully they have some tools at the house, because I'm sure a bunch of crap is closed today.
 
That method doesn't work for split coil boots, I'd swap cylinder 2 coil with cylinder 6. See if your misfire moves
 
I just did the boots, when I did plugs and valve cover gaskets. I don't think they would have split already.
 
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