Ford F-150 & Expedition 5.4L 3V Triton Engines Hard To Diagnose Misfires Fixed!


Hey, guys, what's up. Welcome back to the for tech, make your local channel. Today.

We have a 2009, Ford f-150 with the 5, 4 3 valves in it. But it has around two hundred, eighty-seven thousand miles on it. So it's got a lot of miles on it. But it runs good it's, probably a timing job at some point in time as has all new coil packs on there has been maintained really well and that's.

Why it's gotten this far, but the customer has a misfire on number seven. And no one can diagnose it he's hard to a couple shops. Around the area, the first one told him, and he put on some plugs and coils make it all new, and that should take care of it didn't take care of it.

And then the nut shop said that number seven injector was sticking intermittently causing the issue replaced. It didn't fix anything. Then they sent at the injector sticking back fed into the PC, and it's, a classic mechanic CYA. If that fat is shorted into the PC and took out the PCM driver for that a particular injector replaced, a PCM, nothing.

He brought to. Another shop, they said that cats were plugged up causing back pressure causing misfires, which does happen, especially in this engine. They replaced it without even doing a full diagnosis, apparently replaced on all new cats, all new cutback exhaust system. They put on there to guess what same problem guy reaches out to me says, hey, we can take a look at it. So I said, sure bring it on down number seven misfire was the key my head already I knew a roller follower had popped out why because I have a. Lot of experience with these engines that's, the first thing, but I've seen it quite a bit recently, an advertisement sum number, seven number seven. So an intake roller, follower pops out and sits there in the head that's, the best outcome you can ever have.

Because if this thing starts jiggling around on, there starts getting in the way, and you will destroy itself, so I'm thinking, that's. What this is what the situation is this one too, because of the mileage overnight and newer, especially had a lot of. Problems at roller followers, failing in them, not sure if they're original or not and just by everything else has been taken care of on there.

So it's like it's, pretty obvious that we need to go into base engine. So we're going to do now they're going to bring it over the scan tool show you had a few basic pre-checks that I do for this kind of concern, and then we're going to go ahead and pull the valve cover together and see if it truly is four or eight dollars now roll our follower that's causing all these. Concerns I bet it is okay. So here are some results from my test drive.

So I went for test drive I used a Ford, Power, Balance tool and I. Watch all cylinders power contributions going down the road. And sure enough intermittently number seven, you can see the drop out right here. All the rest of cylinders are a-okay. You know, all this all over the places from deceleration and stuff like that. But to beat the dropout is an actual misfire, and you can see it's not all the time. So you got to really work.

To get it to do it deceleration stuff like that, not the usual upon acceleration, misfire that's associated with the second year. Ignition failure. Okay, so you can see, yeah, it's there. Okay. So I wanted to show you guys that before I clear.

This out ask my little test drive. So the first thing I do when I have a concern like this is I'll go to mode, CIGS data, and I'll. Look for, you know, the history that it records for the misfires and all the other data inside there.

So as you can see, it records. Specific misfire data for each one of the cylinders in here. So you go down the columns on, you have a min Max. And the actual value C look down.

These are all cylinder, cylinders, and they're all 0 pounds. And we get to number seven and look at that, I mean, so it's random, but we're still racking up a good amount of misfire counts on there. It's pretty obvious. We have a concern on number seven, ok. So at this point, let's, go ahead and pull codes make sure there is anything we are going on with rich.

Or lean, so we'll, go ahead and do that sure enough feeling only have misfire codes, you know, these are all kind of random on here and this one's specific right there. Okay, take 30 codes. Couple times got a P 1000 in there. Okay. So we got number seven, that's, it's, definitely recognizing it. And you know. So next thing we'll do is we'll.

Go ahead, and we'll do a relative compression with the scan tool to all the stuff takes about five minutes. And it really eliminates a lot of things that are going on here. Now this right here is interesting part about it right here. We're doing a relative compression with the scan tool and that'll, basically, compare crankshaft acceleration, commit they'll.

Compare it to the other cylinders it's all relative to the other cylinders, relative compression. So we'll give you a basic loss of compression on each one of the cylinders on here. And once it gets into the yellow or even the red I, guess they can go down that far it's a big concern. So anything below like, you know, five. Ten fifteen percent you have a problem in that cylinder with the base engine. So the fascinating part about this is this will check base engine. Valves can valve seats do do do ring seat.

And the cylinder walls is there a hole in the cylinder. And you know, all that kind of stuff is what this actual actually checks how well the cylinder seals. Well, if that ruler Fowler popped out to the side and that valve just closed all time? Well, guess what that valves going to seal just fine so that's? Why it's not. Showing up here on the relative compression. So you have to realize that to you looking at base engine at this point, but it looks good.

You need to look further. Remember, there's, there's, there's, two, intakes and there's, one exhaust valve. So if one of the intakes flies off the handle, the cylinder will still work. Okay. So we'll have it'll run smooth at idle and all our good stuff will have good compression all that stuff. But the incoming air into the cylinder that the PCM is calibrated for is not going. To be there, because one of the valves is not opening.

Yeah. So of course, we get a misfire because of fuel in 250 running to rich in that cylinder. So I've, everything pulled apart, literally I, pulled out number seven coil and put it aside. Just for the kicks okay. But I haven't, even checked number 7s, spark plug at all. Okay, I've been straight for pulling the bowel car because I said, like I said, I've seen this too many times before, so we're going to pop it inside here, and we're going to do the reveal together. And see if I'm right?

Alright, so this is probably the best angle we're going to get here, everything's, unbolted, we're, ready for the reveal on here. So hopefully I don't, bump, you see what's going on here together can be tricky to get off. Yeah, okay.

So I, don't recall. What it was last time, which intake follower was last time, but here's cylinder, one or that's. The only one this is cylinder. Five, this is cylinder six. And this is cylinder. Number seven, right here. And of course, number eight.

So these followers, Are definitely original they're, not the latest and greatest small hole design, the smoke wheeling, hold on there, all these feel tight all the way along even the ones on seven here. Okay. But as you can see are, you will be Oh.

See there it is you see right there, it's sitting right there and that's the intake lobe. So your intake, exhaust intake on number seven. So you know, usually it's giving you a warning. Typically they start, you know, the bearings they fail in here. So there's lash. So you did, you know, It's pretty much constant, because the lash is always there.

So there is certainly a warning there, but if you have an exhaust leak like this guy, you may mistake it and ignore it, you don't want to ignore it. But again, this is the way it typically as it gets kicked up over to here or even down there, but usually over here because the rotation of the engine and that's the best thing that can happen to it get stuck up in there and out of the way. Okay, we still need a full set of roller followers on here.

You can see this one's toast still spinning, but look a little ash in there that's. All it takes you've all ash in there. It gets loose there's, nothing holding it in place and just flies out. Okay. So this one I mean that the cams pretty chewed up on here, so you're trying to replace the cam on here and stuff like that, honestly, if he hasn't had any job and how long replaced that to you timing job on here, but yeah, there it is.

So because a lot of people are getting taken. And because a lot of techs are. Misdiagnosed in these yeah now, see the bearings are plated wiped in there. So at that point she's too much last hole into place, this has been taking for a while. So yeah, I just wanted to a quick video on that to show you guys what to look for I. Guess? If you have a hard to diagnose misfire on the 5, 4 3 valve everything else checks out, and you've done your checks for everything else.

Everything's. Good to go. You may want to look at the base engine here. Most notably the roller follower because like I. Said at idle and everything else this thing runs great, because it still has an intake and an exhaust fall around there and that's. What usually always happens the intake follower.

So only under certain conditions, it'll misfire on you so that's about it, I just want to show you guys. This is really a thing out there I've seen quite a few of these, and it's always been number, seven intake for whatever reason so that's all for now I hope it's helped you guys fix your Ford yourself. See you guys next time.

Dated : 09-May-2022

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