In this video I have a look at a 2011 Buick Enclave with the big 3.6 that was sent to us from another shop with a customer complaint of, "it starts and stalls and we can't keep it running more than a few seconds....sometimes."
Sounds interesting enough.
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All right folks, gonna share with you. Uh, a case study? I'm kind of in the middle of I Haven't had one that's been super interesting in a really long time. If you guys don't like case studies uh or videos without you know, rust torches and air hammers, close the window. go watch something else right now.

So just forewarning, it's going to be kind of boring and semi-nerdy and we're going to be looking at a computer screen 2011 Buick it's The Enclave It's got the big three six hundred, eight thousand miles on it and I'm the third shop uh to have the thing. So here's what the customer told me. uh, they hopped in it, she drove, you know, 40 minutes away. went to the store.

everything's fine, cars been fine. uh no engine lights anything like that comes out of the store. All we'll do is start, install, start, stall, start stall. uh hat called tow truck, she got a ride home just went to shop number one.

They put the cam solenoids on it. they did a uh all the injector or all the coils, all the spark plugs. you know, you know the host of of Parts there. uh of course that didn't make it any better.

Still start stall, wouldn't run. They took it to shop number two. Shop Number two put a crank sensor in it and then they also told me that they redid the plenum gasket because Shop Number one screwed up the plenum gasket. That's what I'm told.

Uh, long story short, Shop Number two did that stuff still start stall They said you know major electrical wiring, computer, something like that and then they got towed here. So I looked at it and it's kind of bizarre. So it does. It'll start install sometimes it starts and stays running.

Uh, for you know, a given amount of time. a minute, maybe two minutes, maybe five minutes and then it stalls. if you keep it revved up like let's say, you prop the throttle at, you know, 2500 RPMs It will continue to run, but you'll hear the engine die out just like shut the key off and turn it back on. At that time, you'll see the uh, tachometer will drop out too It'll Be steady, then it will drop I'll show you because it's still acting up here.

So at that point I'm thinking, well, you know what are we going to do? What are we looking at? We got no codes, doesn't throw any codes I'm thinking something crank related, crank sensor related. So first thing I did grab the Pico I tapped into the PCM over here in the corner and looked at the crank signal and that sucker is Rock Steady Right up to the point it stalls even though the RPMs on scanded are dropping right to zero when it doesn't say they shut right off to zero. Uh, the crank active tooth counter on the scan tool goes all crazy too. So that's why I'm taking some kind of input.

possibly a bad PCM because the crank input looks good. So let me show you what this car is doing. So I'll reach in here and start. I got my throttle prop there, but we're just going to start it, see if it'll start so it starts runs.

Sounds pretty good. you know, for a 3.6 it sounds pretty good here. Just have a listen to it. I mean it doesn't sound like you know timing? Chain's ready to jump through the cover or anything like that.
Give it a minute usually makes it can be really erratic. so we'll um, take and give it some throttle here. Foreign just holding the throttle there. You guys seen that glitch like that and that's the problem.

It gets a lot worse and I'll show you where I'm at with it and what I think I've discovered? Let me just give it the classic rev up. tune up here if I can reset pedal There we go. There we go. we just stall about it.

All right? Oh perfect. Let me pause this. I'll show you what I think is happening I guess First and foremost I Want to see if we set any codes up until this point, it hasn't. If there is any, there's been no, you know, real Direction in that regards.

let's see here. read codes again. just in case. Yep, so no codes.

So I'll be honest with you. You know I found that super weird and it was kind of leaning me towards. you know, possibly a bad PCM and that's why I started kind of checking inputs. you know I checked.

you know alternator output. make sure there's no excessive AC Ripple uh you know a couple other inputs there, mostly looking at the crank signal, really thinking that's going to find something there. but what do we have on the screen right now are just four lines. Let's click back here.

This is where we ended it. Okay, so what we have on the screen is all of our cam signals. So I looked at the crank signal I saved some of them files I can share with you guys. but I was looking at these cam signals uh to see if I saw any anomalies with them.

So uh, the blue is bank one exhaust. this is Bank two exhaust. this is Bank two intake and they they I don't say they mirror each other. they're um you know bank one and Bank two exhaust.

You can almost. if the engine is perfectly in time, you can stick these two over top of each other and they you know they're exactly the same and and same goes for uh, the intakes. You know you can throw them over top of each other and and they're good. So I'm just kind of collecting data looking through it and then you know I had this epiphany.

um actually I got to see. You know what happened I got to see when it broke and let me just see if, uh, see if we can see it here and we can. Okay, so the problem is on this. Trace right here the problem is on uh Bank One intake.

So this yellow Trace down here and it Goofs up and then after it Goofs up it dies so we can see. If you just you know, simply want to look at the pattern like two little humps. Two big humps, two little humps. Two big humps.

you know and that pattern you can see here just repeats itself. Let me let me flip back to a screen before it stalled. Um, it will just enhance. We'll just look at the intake trace on bank one and Bank two.
We'll zoom in on them a little bit and like I say you can see two little humps two big ones, two little humps Two big humps. Without getting too technical about it, you know this is what the PCM sees. This is the raw data coming into this little guy and let's see if we see any anomalies here. just again.

being as simple, reminded here: two little ones, two big ones, two little ones, two big ones. Easiest way to do it is just to Overlay get one on top of the other. They essentially should almost disappear. The timing on these engines are never right on the money, but we don't see anything weird.

Nothing's really jumping out here. I'll back up another screen. nothing really weird there. Let me uh, an enhance and then we'll go to different waveform right here before it stalls.

Look at this and I can show you on another diagram. Also, I'm gonna move our green Trace up out of the way. but you know we got two little humps, two big guns, two little humps. two big humps.

So we're too little, too big and then something happens through here. You know we get this extra trigger. Okay, let me show you a better probably should have saved that. We're going to look at a waveform I already saved.

So this is bank One. Now this is just going to have the bank one intake and exhaust and crank. just bank one only. but I think I think this one still had the problem that I saved.

This is where I initially saw it. so I let this load up. Let's see I usually labeled my channels, but let's see Channel labels here. Okay, so we're looking at bank one intake so we're interested in the green trace this time, so let's just kind of scan ahead.

Oh, actually I saw the problem right there. so we'll go back here. We'll move our crank crank signal down because our crank signal we're good. This is the exhaust on bank one.

This is intake on bank one. and like I say we're supposed to have two little humps. Two big humps, two little humps, two big humps, Well look here. Got a big hump, Little hump, two big ones and then you come through here.

You know, or you can just see that the spacing is off. Um I Don't know how to technically say it to you, but we'll come through here. We see another anomaly instead of having you know too little, too big, two little ones, two big ones, and then all of a sudden, a big one, a little one, and two big ones. and then you know, three little ones, and then it's moments after this.

This is just brief seconds, go by the car stalls and you know, and this is the car just shutting off and you know, petering off. So I guess what I'm getting at is could we have seen this or isolated the problem? seen the problem without using a scope? I Certainly couldn't There's no codes, there's no Direction but I guarantee you that this is what's causing a car problem and we're going to prove it right now because we're gonna unplug Bank One Intake the one that was running on our yellow Trace We're gonna unplug that. Yeah, this file I started to save and then my battery went dead. So um, we're gonna unplug it.
We're gonna start the car and I bet you dollars to Donuts Once we unplug that, this thing should stay running good And this is where I wanted to bring you guys along I should have brought you through the whole process, but I was kind of scratching my head here for a minute trying to get some direction. This is where we're at I'm gonna get my stuff back on the screen here. We're going to unplug the bank one intake that has these extra pulses on it from you know, from whatever it's getting them from. whether it's mechanical damage, um, you know that's to be determined or if it's you know, a sensor just going stupid, let me get these all up.

I'll get everything sorted, we'll get it unplugged and get it on the screen. so it should be the rear Bank intake. So it's going to be this one that's closer this way like this. I Don't know.

of course I got her really freaking toasty right now. that's a little too toasty. Um, let me get this. Let's see if we can't uh, unplug it because it should run with one of the cam sensors I gotta set, you know? I Can't get that sucker see toasty now I'm just going to get a mirror down here.

I Don't believe that the shops the previous shops had uh replaced any cam sensors I Think they told me that they did the can solenoids there in the end of the head I Think that's what they told me that they put on it for whatever reason which I'm not sure with no codes, no direction I Don't know why you would unload those parts at it I Just want to get a mirror down here and see if these cam if the cam sensor yeah, the solenoid has definitely been replaced. oops sugar. uh the sensor I got to find the sensor that I got unplugged. Um oh okay, there we go.

So the sensor that I unplugged, it looks old and Dusty and the bolt doesn't look like it's been touched. So I don't think that they've replaced it the best. I can tell it does not look new and shiny. the solenoid.

However, actually both those solenoids are brand new or pure brand new. but like I say I don't know why you know what the thought process was other than you know, probably just guessing at the problem. you know why did it get all brand new coils and new spark plugs? and for a start stall problem like oh, that's needed here and or there. So let's start it up with this unplugged.

We shouldn't have anything up on the screen. I'm expecting, uh, an extended crank would be my guess. but if we're right and that signal is screwing up stuff, uh, whether it's screwing up, you know, spark timing or injection, or you know, whatever whatever parameter the Pcmc and then it's saying well wait a minute and it starts messing with stuff till the engine stalls. Uh, that's my educated guess.
Let's fire this thing up here. I'll take you around with me I Don't know. but I don't know. Shut this off.

I might have to try it twice. There we go. Yeah, a lot of times when it's missing cam signal, it's got a take a minute. Oh, actually, let's see.

let's hold the RPMs up because it'll act up every time. When we do that with you, look at that. what'd you look at That we just gotta do a cam sensor delete. Leave that baby unfold.

Skip it so that's interesting and then we can see. Oh, that's our yellow trait's the one that was goofing up on us here. Let's move these down. there we go.

So our yellow Bank One intake. that's how I have it labeled here. We've got that unplugged. That was the one that was throwing a a little hitching.

It's giddy up for whatever reason. so now we can take. we should be able to plug that back in to prove our Theory because if we plug that in, you know it's going to hoop up again. It's it's my assumption.

Wait a minute. Oh man. So I'm going to plug this thing in. There's something hitting that cancer.

I Can feel it. Oh yeah, no, there's Oh no. there's something hitting this thing. Oh man.

I don't know how to show you that. Um I Got an idea. You might be able to hear it. Let's get a long screwdriver.

Stuck a megaphone on the end of the screwdriver. I'm gonna stick this on that cam sensor. See, you know, because this produces sound. Oh yeah, you can hear it.

So all I've got I've got the screwdriver tip on the cam sensor. Oh, it is an Oem one. I can see the mark on it? Hear that? That's not a sound you want coming from your cam sensor. Lady: Um, that could be bad.

I'm gonna take it out with you I'll take him. plug it in here. it should act up and plugged it in. Yeah dude, we can.

We can feel that thing hitting I Don't see it goofing up on the screen. Let me rev it up I assume once we rev it up, it'll correct screwing up. We got a trading back across the screen here. sorry for the moving you around I Know this isn't ideal like just pointing at the screen.

Oh yeah, I just screwed up right there. We back it back up. Get right there. That's interesting.

It didn't stall, but we can see, you know, right here. She threw some kind of triple Banger little Mark but it's interesting. When it processed it, it didn't stall. But perhaps it's not looking at that cam sensor anymore, but it should have Certainly should have thrown a code.

I Would think there should be a code in it now, because we had to. Oh there it goes. It just died. Of course we didn't have our scope recording, but yeah, so look at that intake cam sensor circuit one high voltage because we have it unplugged I'll be dipped by.

That's not really the issue. I don't think we got a bad sensor I think we got some funky Funk product going on that engine or something coming apart probably. Um, that's kind of pissed pot to get to I Went ahead and unplugged it. again.
This thing's hotter than my mother right now. You know how hot mothers get some of them. Um I Want to see if I can't? It's down here with a 10 millimeter offset wrench. I'm kind of curious here before I go home for the evening I Kind of want to see what's up.

you know. did the okay the the nut broke loose, the bolt broke loose, power steering line is my sensitive skin can't take it. see if we get this bolt out of here. at least pull this sensor out and find out what and the Thunder happened I can't imagine like the sensor swelling up and you know just all of a sudden hitting the end of the cam.

see if I can get the bolts out of it here or the bolt singular. Whoa. that's freaking hot. Come on man.

Oh yeah, there's the bull. about 900. Degrees Hopefully it was the right bolt. it appears that it was.

and let's see if I can't let me get a long screwdriver see if I can stick down in there folks. Thank you. Where I saw you I saw you. It's too freaking hot.

Come on. Slide out of there. There we go. there we go.

I'm the pop pop what we got boys. Okay, let me set this down. Got nothing that's freaking metal. So what do we got? The OEM sensor? She's all rounded off.

It sits in there like this, right? Yeah, it's about like this. Connect your faces up, that's interesting. Something's definitely chowdering into it there. Huh? I Hope that focuses for you guys.

You can see it. Don't look at my nasty yellow fingernails. All right. Forget about that.

We're working on this. Okay, you have to get past it. Uh, let's get a mirror and see what we can see. You can't look to see what you need to see unless you know what you expect to see.

According to Napa they got know-how This is what the right side intake. uh, Cam sprocket looks like two little humps. Two big humps. So this when this trigger goes in front of our hall effect sensor, this is what we This is what we interpret on the screen.

We see that you know the two little humps and the two big humps so to speak. or the two little gaps and the two you know big gaps I Don't remember which one pulls high or pulls low, but either either case this is what we're looking for. The cam sensor sits. um, in here.

Where'd that go? That's right here. So essentially our cam sensors, you know, sits here. and then as the cam spins around, you know it interrupts the signal here. and you know, gives us our two big humps.

Two little humps. We're keeping this really simple because sometimes that's the easiest way. but maybe one of these veins is bent or this is coming apart. you know, rubbing on this.

That's what we see and that's what we can only assume. And I shoved the mirror down there wherever it went. That's right here if I shoved that down there. But it's really of no help because we need to Bar the engine over I can only see one one Vein on there so to speak.
I don't know if you guys can see it. yeah in that hole so we can only see one. but we need to bar this engine over All right? So here's the dealio: I got the depth stack endoscope kind of Twisted down around and just resting in the perfect position so we can look and hence inside the cam sensor hole and we can see the trigger. You can see what we need to see I've got the wheel removed I've got a ratchet over here.

We're gonna see if we can't bar this over and have a look see. If we come up on any real anomalies here. stop and look at that one. I gotta kind of stick my head in here.

It's really hard to see anything I mean I think it looks like it's shiny right there. but let's just go all the way over. Oops. hold up.

let's back it up son. bad idea to spin the engine backwards. Oh boy yeah. but we can see that this can be this cam feature is not locked.

obviously because we can see the trigger kind of snap ahead there. Oh look at that. Did you see that sucker that thing like moved back in. Look at that.

I don't know if you guys. So I spun it backwards. watch I'm going to spin it ahead. Yeah, it sucked back.

it's sucking back. Look at that and it stands still. Oh yeah, this cam phaser. this thing's frigged.

ain't that some stuff, huh? So we saw we saw that sucker pop ahead. Yeah, this thing's coming apart. man there it is. Also all right.

she broke killing myself. a little bro bro. All right we figured it out. I'm gonna spin it backwards.

bad idea, but we can see on that Center where that thing has been whacking I See, stand still again, camps moving or you left. you're standing still. look at that. What would you look at that? I Don't think we really need to look anymore.

we're just gonna. We're just doing it for fun at this point. but Boop But that was pretty interesting. You know how the uh, the trigger there, how it kind of like pop forward you know? and that's what's causing the physical damage to the sensor So that's pretty cool huh? I think it was this vein right here.

it's out pretty close. I think we see. Yep, there it goes. It sucked back in.

it. sucked in right there. it's gonna come out and slap your mom. okay, still holding still.

Oh, we're losing it. Yeah, there she goes. All right. we're done spinning over.

I'm wearing a little arm out hoping you guys are in Focus here. I could see everything your hands so that's it. The power of the Pico and an endoscope. you know exactly where to go and I guess that's it folks.

there's nothing more to see more. just got to come out. It needs a motor lady. Uh, it doesn't really need a motor, it needs a timing set.

so uh, the engine's got to be dropped. timing covering needs to come off. chains phasers. typical GM 36 stuff.
First time I've ran across this symptom though. um you know with this start stall which I didn't Honestly didn't think I was gonna find anything in the cam timing. uh just because I've had these things come in sounding like diesel trucks and cam timing off the chart. Every cam code you know Under the Sun for cam correlations over Advanced uh you know Cam's you know, so on and so forth and they always run.

They run great so and like I said I've had them off like teeth and they still run and they run well. So I really was kind of surprised when I saw what we saw and I guess I just wanted to make this video a to bring you along with where I thought we were going with it once. I saw you know the anomaly on the on the scope and also to show you the power of using a scope without really having to be super smart looking at it like you know, big hump, little hump. You know it gets more complicated than that folks, but oftentimes that's all you need to know is you know.

here's my waveform: What should it look like? what does it look like and why is it doing what it's doing? You know, why do we have missing teeth? Why do we have you know this extra trigger like that's kind of weird. Uh, you know. and I've showed that before. um I think we did a video like on a Honda 35 where the actual cam trigger itself was just effective.

It was magnetized or something and it was just leaving. You know, the pulse if you will on the big pulse. It was just on for too long and we look at it and there's physically nothing wrong with it. We change the cam pulley and bada bing bada Boom! Robert's your mother's brother and it fixed it.

But the fact of the matter is, you could have never ever done that without. You know a scope without being able to see what this computer's seeing. And that's what we see here. We look to see what the computer's seeing I don't know why it's doing what it's doing like I say whether it's screwing up, you know the spark timing or uh, you know the injection timing based on what it's seeing.

you know I don't know and it's really not worth knowing because you know we know what the problem is. All we know is, uh, you know, garbage in garbage out. let's get bad input. it's putting some bad outputs out and that's all we can say.

Um, so hopefully this video isn't too boring. You guys got to see what I saw and you know we're LED right to the answer without putting any parts in the car. and now we just got to call the customer and let them know that you know, let them know what it needs. It needs a timing set so I'm not sure if I'll get the job on it I'm about four weeks out on appointments right now for you know, something of of this caliber so we may want to take it to another shop to have it fixed.

but at least he knows that once they you know hang a full GM timing set on it chains, everything provide. They don't screw it up, it'll be. It'll be good and the car will will work and run. and who knows.
that sensor may still be good. It probably is, but I would replace it anyways because it's all chowdered up. It looks like we got done just in time because the battery died in this. Okay, and I want you to go down before the battery dies in your phone, smart device, computer, whatever you're watching the SMH channel on.

Leave a comment down in the comment section. Let me know how you would have traced this problem down and what do you think about the value of a lab scope. Is it necessary or isn't it? and how would you have found the problem without it And just let me know down there questions. Comments: The Entity The Facebook You guys know what to do and just remember viewers.

If I can do it, you can do it. Thanks for watching foreign.

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