17 Yukon XL 6.2 stalling, hard to start, injector issue

[Eplumer400]

Bought a 2017 Yukon XL 6.2 back in May and overall haven’t had too many issues other than the motor mounts being bad and replacing those under warranty. On Thanksgiving, we drove about 250 miles to a campground without issues, but about a mile before the campground, after going over a large bridge, the engine died and would not start again. The push to start caused the battery charge to get low pretty quickly, and after about 3 or 4 steering cycle attempts the engine would not turn over. Engine was not overheating, voltage and oil pressure were normal, but check engine light came on.

Let it sit overnight and ended up replacing the battery, which we planned on doing (just not at this time). Vehicle started up but was a little slow to crank, and took it to autozone to have them test the alternator, as Google had suggested. As I crank it up at autozone for them to check the load, it barely started, and because I was afraid of it not starting again I left it running while I finished my business inside. Due to being out of town I ended up buying the $520 alternator (WTF is that price?) that they had in stock as the $280 one would possibly not be in on time and we still needed the vehicle for the week. Replaced the alternator easily at the campsite, but the check engine light came back on. Went out a couple days later and had the check engine checked, where it gave the P050D code for cold start rough idle and C0800-03 for “control module power circuit- low voltage”.

Didn’t have the tools with me to do the injectors at the campsite so I bought fuel injector cleaner, and put that in when we left today. Truck barely started when we filled up, but luckily made it all the way to the driveway before it stalled out in reverse backing up the driveway. Was able to get it started again but I’m concerned about the longevity of all this.

I’m fine with finding out if the battery/alternator were a waste of money, but don’t want to buy injectors if I don’t need to. Only other part I’m thinking is causing these issues is the starter, but it wouldn’t cause the truck to go out while driving. Does anyone have an idea of what’s causing this, and if I need to have the injectors replaced or not? Thanks in advance.

 

[Fless]

When you say it "barely starts" is that a slow crank, or an extended crank (normal crank speed but takes a while to fire up)?

 

[Eplumer400]

When you say it "barely starts" is that a slow crank, or an extended crank (normal crank speed but takes a while to fire up)?

It’s a slow crank, like it barely wants to turn over at first, but will start up once it gets going, usually within 3 seconds.

 

[Fless]

Here's one that was solved with injectors (posted by @ReaperHWK):

2015 Tahoe, P050D Code (cold start rough idle)

Some history first. 1)Few weeks ago on a trip home the Tahoe threw a code, it was a P0300 Random Misfires. I could tell it was running rough. I replaced all the plugs(truck has about 120k miles) and it ran much better. P0300 went away. 2) A few days later it then threw a cylinder 8 misfire...

www.tahoeyukonforum.com

But perhaps an injector balance test would give you more data.

 

[Joseph Garcia]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving clarifying questions from the knowledgeable folks on this Forum.

Before firing the parts cannon, let's check out a few things. Thoroughly check out your positive battery cable to the main fuse, the battery to ground cable, and the the battery to starter cable. That INCLUDES doing an OHM resistance test with a multi-meter for each of these cables, because they generally rot from the inside out, and you won't see that. I'm 'assuming' that you checked all of the battery terminals and ground connections to ensure that they are clean and tight. If not, do so, and that includes the ground strap from the motor to the firewall.

So many of the '**WTF**' issues associated with these trucks are related to not having properly maintained proper voltage and effective connections, including grounds.

 

[Eplumer400]

Here's one that was solved with injectors (posted by @ReaperHWK):

2015 Tahoe, P050D Code (cold start rough idle)

Some history first. 1)Few weeks ago on a trip home the Tahoe threw a code, it was a P0300 Random Misfires. I could tell it was running rough. I replaced all the plugs(truck has about 120k miles) and it ran much better. P0300 went away. 2) A few days later it then threw a cylinder 8 misfire...

www.tahoeyukonforum.com

But perhaps an injector balance test would give you more data.

I appreciate it. I did see this thread, and unfortunately if the injector replacement worked for him it sounds like that’s in my future.

Forgot to add I’m at 106k miles and I know the injectors are a known issue around this time. May just do plugs and wires while I’m at it for good measure.

 

[Eplumer400]

Welcome to the Forum from NH.

Lots of knowledgeable folks here who freely share their knowledge, experiences, and perspectives. Knowledge is power.

I hope that you will become a participating member in the Forum's discussions.

Pics of the truck, please.

You are already receiving clarifying questions from the knowledgeable folks on this Forum.

Before firing the parts cannon, let's check out a few things. Thoroughly check out your positive battery cable to the main fuse, the battery to ground cable, and the the battery to starter cable. That INCLUDES doing an OHM resistance test with a multi-meter for each of these cables, because they generally rot from the inside out, and you won't see that. I'm 'assuming' that you checked all of the battery terminals and ground connections to ensure that they are clean and tight. If not, do so, and that includes the ground strap from the motor to the firewall.

So many of the '**WTF**' issues associated with these trucks are related to not having properly maintained proper voltage and effective connections, including grounds.

Saw this right after I posted my latest reply. I’ll do a once over with all the connections and double check before ordering stuff. Thank you for the response.

Pics, as requested. Swapped the Suburban for the Yukon XL

 

[Eplumer400]

Checked all connections, and everything’s tight. P050D code came back, so I took the intake off to get to the part numbers for the injectors. It was a pain but got it, and I ordered the injectors. Curiously enough, the P050D code went away after I put everything back together. Still starts the same way though. Just waiting for the injectors to come in to do the replacement.

 

[Doubeleive]

Checked all connections, and everything’s tight. P050D code came back, so I took the intake off to get to the part numbers for the injectors. It was a pain but got it, and I ordered the injectors. Curiously enough, the P050D code went away after I put everything back together. Still starts the same way though. Just waiting for the injectors to come in to do the replacement.

it might be too late now I think the special coverage expired in oct of this year (might depend on your production date) but many of the k2's had a special gm 10 year coverage for the fuel injectors, had all the injectors replaced on the wife's rig this summer by the dealer, no cost. It might be worth checking out with the vin and your local dealer it would be in the gm system only.
here is the announcement

https://static.nhtsa.gov/odi/tsbs/2019/MC-10163854-9999.pdf

 

[Eplumer400]

it might be too late now I think the special coverage expired in oct of this year (might depend on your production date) but many of the k2's had a special gm 10 year coverage for the fuel injectors, had all the injectors replaced on the wife's rig this summer by the dealer, no cost. It might be worth checking out with the vin and your local dealer it would be in the gm system only.
here is the announcement

https://static.nhtsa.gov/odi/tsbs/2019/MC-10163854-9999.pdf

That would be great but unfortunately I live in SC so it doesn’t apply to me. Injectors will be here Saturday. Today it threw a new code, P0305, cylinder 5 misfire. It’s running rough while in drive and moving but runs okay in park. Can’t wait for this to be over.

 

[Eplumer400]

So little update. Two days ago while my wife was driving the “oil pressure low, stop engine now” light comes on, and after she pulls over and turns it off, it wouldn’t start up again. Had it towed home, and let it sit with the trickle charger on the battery for a few hours while I was at work. Once I got home, I started it up, with a new crankshaft position sensor code (P0336) displaying. Turned it off, and removed the battery and alternator to have them load tested at autozone, and they both passed. Put them back in, and so yesterday I tried starting it again and it turned over once and then clicked. Removed the starter and bench tested that at home, and wasn’t able to get it to activate. Got it replaced, and took a drill and wire wheel to the grounds behind the front wheels just to be safe (thanks for the locations on another post doubeleive), and it’s starting up fine with no issues. No check engine lights (yet), no stutters, no misfires, no issues whatsoever. The injectors came in the mail today, but I’m hesitant to install them just yet. Probably gonna wait a week or so and see if I have any issues and go from there. Not sure if the new starter, the grounds, or both alleviated the issue, but I don’t care, as long as my family isn’t getting stranded on the side of the road.

 

[Joseph Garcia]

So little update. Two days ago while my wife was driving the “oil pressure low, stop engine now” light comes on, and after she pulls over and turns it off, it wouldn’t start up again. Had it towed home, and let it sit with the trickle charger on the battery for a few hours while I was at work. Once I got home, I started it up, with a new crankshaft position sensor code (P0336) displaying. Turned it off, and removed the battery and alternator to have them load tested at autozone, and they both passed. Put them back in, and so yesterday I tried starting it again and it turned over once and then clicked. Removed the starter and bench tested that at home, and wasn’t able to get it to activate. Got it replaced, and took a drill and wire wheel to the grounds behind the front wheels just to be safe (thanks for the locations on another post doubeleive), and it’s starting up fine with no issues. No check engine lights (yet), no stutters, no misfires, no issues whatsoever. The injectors came in the mail today, but I’m hesitant to install them just yet. Probably gonna wait a week or so and see if I have any issues and go from there. Not sure if the new starter, the grounds, or both alleviated the issue, but I don’t care, as long as my family isn’t getting stranded on the side of the road.

Most likely the ground. These trucks are extremely sensitive to loose or dirty ground connections.

Thank you for giving @Doubeleive credit for providing information on ground locations.

 

[Doubeleive]

@Eplumer400 if it was me based on your reported issue's I would order a oil diagnosis kit from blackstone labs, just to rule in/out any potential internal engine problems
it's going to take a week or so for the container to come and then another 2-3 weeks for then to get you results. If it doesn't goof up in the meantime.
it's definitely strange and these k2's do have ghost's in the machine a passing oil test would put me at some ease.
IF the oil test shows excessive metals that's going to be more work, maybe hold off on the injectors until the test's results come in.
just my 2 cents

 

[Eplumer400]

@Eplumer400 if it was me based on your reported issue's I would order a oil diagnosis kit from blackstone labs, just to rule in/out any potential internal engine problems
it's going to take a week or so for the container to come and then another 2-3 weeks for then to get you results. If it doesn't goof up in the meantime.
it's definitely strange and these k2's do have ghost's in the machine a passing oil test would put me at some ease.
IF the oil test shows excessive metals that's going to be more work, maybe hold off on the injectors until the test's results come in.
just my 2 cents

When I had the intake off to check the injector part numbers, I looked inside the intake and noticed it was excessively dirty. I bought sea foam to do a cleaning but wanted to make sure it was running well again before I introduced something else to the mix.

Problem is, it was running fine today for about a half hour until we were getting off the freeway, when it gave the “low oil pressure turn engine off” warning again. Started running rough, and it generated a p0016 code for the CKP. Had to sit and wait for a coworker to come get me while my wife stayed with our 3 kids, take me to the airport, rent a car, then come back to get them. After this third time of it dying and leaving us stranded, we’re done. I left the battery disconnected while it sits in a parking lot, and hopefully it’ll reset and start and run long enough tomorrow so I can go trade it in at the dealership and get something else.

For reference, this was the intake:

 

[Doubeleive]

When I had the intake off to check the injector part numbers, I looked inside the intake and noticed it was excessively dirty. I bought sea foam to do a cleaning but wanted to make sure it was running well again before I introduced something else to the mix.

Problem is, it was running fine today for about a half hour until we were getting off the freeway, when it gave the “low oil pressure turn engine off” warning again. Started running rough, and it generated a p0016 code for the CKP. Had to sit and wait for a coworker to come get me while my wife stayed with our 3 kids, take me to the airport, rent a car, then come back to get them. After this third time of it dying and leaving us stranded, we’re done. I left the battery disconnected while it sits in a parking lot, and hopefully it’ll reset and start and run long enough tomorrow so I can go trade it in at the dealership and get something else.

For reference, this was the intake:

that's what happens with the direct injection engines, that has to be cleaned then it will run better

 

[Eplumer400]

So a bit of an update. After having all these issues, I gave in and took it to the dealer to have the problem diagnosed. Was able to get it started up again to drive it to the dealership, where it had this awful noise while the engine was running that I’ll attach. Dealership called today and said that the engine had a lower rod engine knock and that the whole engine would need to be replaced, and it would cost $12,000. While I know it’s possible that the engine needs to be replaced, is it likely that just one rod knocking and/or a stuck lifter would cause the entire engine to be replaced? Just seems like they’re kind of overstating what’s wrong with it in hopes that they can make some money with it. I’m stuck between a rock and a hard place on this because my family can’t be without a car but I obviously don’t have $12k just sitting around to have it replaced. If it actually does need replaced and I want to go through with the repairs I’ll likely do the swap myself with a long block crate engine, but just need some reassurance that it’s actually worth it.

 

[Eplumer400]

I realized I never attached the video. Don’t mind the hazards clicking.

 

[15burban]

It's faster for a dealership to just replace the engine rather then pull it out and "rebuild it". And who knows what they'll find once they open it up. Kind of the same if a guy was to do it himself. A lot faster just to yank the old out and in with the new.

Maybe I missed it but was the oil ever checked throughout this?

I dont hear the best but that doesn't sound good. A video from outside would be better but yeah that doesn't sound good. If you got time you could send in an oil sample.

Just a quick search on car-part.com in my area you can find used 6.2s for around $3-4k and remanufactured ones with warranties for $6-7k. Or I'm sure there's better new options, maybe not cheaper, but a better built engine if that's what you choose to do.

 

[Eplumer400]

It's faster for a dealership to just replace the engine rather then pull it out and "rebuild it". And who knows what they'll find once they open it up. Kind of the same if a guy was to do it himself. A lot faster just to yank the old out and in with the new.

Maybe I missed it but was the oil ever checked throughout this?

I dont hear the best but that doesn't sound good. A video from outside would be better but yeah that doesn't sound good. If you got time you could send in an oil sample.

Just a quick search on car-part.com in my area you can find used 6.2s for around $3-4k and remanufactured ones with warranties for $6-7k. Or I'm sure there's better new options, maybe not cheaper, but a better built engine if that's what you choose to do.

I’ve only checked the oil level and not oil from out of the pan to see if there’s shavings in there or not. It’s still at the dealership right now since I haven’t had the chance between work and the holiday to go over there and pay for the diagnostic and have it towed home. Possibly taking it to a different repair shop that I trust other than the dealership for a second opinion and go from there. And yeah I agree that the video should’ve been from outside and with the hazards off, I filmed it during the one mile drive from where it died to the GMC dealership and it was a last minute decision to film it.

 

[Doubeleive]

your cheapest option, presuming a teardown is required is to just go used and have a independent shop do it.
that might get you back on the road for roughly half price figure $4k on engine and $2500 r&r, add a core charge that would be refunded once the old motor is returned.
call around for labor & supplies the local independents will charge to r&r a L86
wells fargo has a 21 month no interest credit card if you qualify (well's fargo reflect), it's not a rewards card but there intro offer is 21 months. no annual fee
if you put 7k on it that's 333 a month.

 

[Eplumer400]

So short update. Got the Yukon home over a period of a couple days and started breaking it down. Intake is still as nasty as the previous photo I posted, but I haven’t taken any steps to clean it yet, so that’s understandable. Got the pushrods out, and sure enough, the third one back on the passenger side (intake cylinder 4 I believe) is bent with some significant shaving on the side. All other 15 pushrods have no damage or are bent.

Obviously the next step is I need to figure out what caused the pushrod to bend. The rollers on the rocker arms looked good and rolled without any issues so I don’t think those need replaced. Is the next step going deeper to the head and examining everything to see what else is going on?

Also, what would everyone recommend on cleaning the intake at this point? Removing the heads and cleaning the valves and intake with brake cleaner on the bench, or leaving it and running sea foam through it after the pushrod is replaced?

Attached is the knock that people had asked from the outside. Still not exactly what people asked for but closer.