2007 Yukon 6.2 stalls/won’t start when hot

[Campie]

While I concur not to blindly shoot the parts canon at it.....

..... I think that concept needs to be weighed versus this being a higher mileage used vehicle that was just obtained. With that noted, while waiting for a bidirectional scanner to arrive.... I would encourage replacing inexpensive items that are known issues with new. I'm talking spark plugs, wires, mass air flow sensor, map sensor, transmission filter change, serpentine belt, inspect the hoses and make a decision.... Personally on any used car I buy, I always replace the O2 sensors as well. Depending on the mileage and the appearance of the water pump, I often do that as well. And prior to the bi-directional scanner arriving, I would clean and reattach all grounds and check the battery condition and cables. (If the battery cables appear original, we all know that's high on a list for replacement)

These are just basic wear items that one could consider in a complete tune-up per se. It also gives one a good starting point to dig deeper with the bidirectional scanner. I see the parts canon as a problem when you're investing a couple hours, and a bunch of money just blindly going in deep without diagnosing. (Lifters, oil pump, injectors for example)

Some items are worth doing based on the mileage..... Preventative maintenance of sorts. If you do your own work, the oil pick up tube o-ring falls into that category.

The overall condition of the vehicle and what, if any, maintenance records should play a part in the overall plan of attack.

Lol, this is just my two cents on how I approach a high mileage used vehicle. I'm sure everyone has a different approach? For me, I won't let my wife drive off in a new to us used vehicle until I'm 99.9% positive she will not get stranded. (She likes to brag that in 39 years she's never been broke down on the side of the road. So she doesn't question my preventive maintenance methodology)

I like the idea of doing the easy, typical parts, whether they actually fix the problem or not. Anything under 100 or so dollars that I can do myself will make me feel much more comfortable when we’re out driving. Unfortunately, our mechanical skills are limited, and we don’t have a lift so anything major would end up being done at a shop. Unfortunately, not sure we can do the oil pick up O-ring ourselves and we definitely have oil pressure that is lower than our comfort level. Hopefully I will give the overfill/nose down test a try shortly.

Thanks so much guys for all your help!

 

[Campie]

I would probably change your crank sensor. Unfortunately, it’s behind the starter. My new NAPA one came with a lousy o ring that leaked so I did it twice. That exact thing happened to my wife after drive home for 10hrs in triple digits. The starter also failed which didn’t help. Changed both and haven’t had the problem in a year so far. Getting ready for a long road trip this summer so we will seee what happens. Good luck with the troubleshooting.

Yes, I am pretty sure I will change the crank case sensor and the cam sensor, just to be sure they are both OK. From what I’ve read, with 160,000 miles both are due. Pretty sure I’m not gonna be able to do that myself though! I’ll have to watch the videos again and think about it… Lol!

 

[Fless]

Yes, I am pretty sure I will change the crank case sensor and the cam sensor, just to be sure they are both OK. From what I’ve read, with 160,000 miles both are due. Pretty sure I’m not gonna be able to do that myself though! I’ll have to watch the videos again and think about it… Lol!

If you change either the crank sensor or the cam sensor, or both, do yourself a favor and have someone do a CASE relearn. It's not always needed but it is recommended when either sensor is replaced.

 

[dkad260]

The car stuttered at the traffic light at the exit ramp, but didn’t stall until we slowed down to turn into the gas station

So both times it stuttered was slowing to a stop and sitting at a light. Both times your foot is on the brake correct? If your booster has a leak, then it produces a huge vacuum leak. If by some strange chance it doesn't hold the vacuum when restarting....it might not start.

The no restart on a faulty booster is a long shot, but should be at least checked. If it stalls and doesn't start, then you take a pair of pliers and pinch the vacuum hose going to the booster. If it starts, then you might have found the culprit.

 

[Campie]

If you change either the crank sensor or the cam sensor, or both, do yourself a favor and have someone do a CASE relearn. It's not always needed but it is recommended when either sensor is replaced.

Yes, I understand it is important to do that. I believe the scanner we got is capable of that process. Thanks!

 

[Campie]

So both times it stuttered was slowing to a stop and sitting at a light. Both times your foot is on the brake correct? If your booster has a leak, then it produces a huge vacuum leak. If by some strange chance it doesn't hold the vacuum when restarting....it might not start.

The no restart on a faulty booster is a long shot, but should be at least checked. If it stalls and doesn't start, then you take a pair of pliers and pinch the vacuum hose going to the booster. If it starts, then you might have found the culprit.

Can you help me understand where the vacuum line is to the booster? What you suggesting sounds like a relatively easy process and would be good to investigate.

 

[Campie]

Yes, we had that problem also. A part of the clamp on the negative was missing. Once we fix that, it was good! This stalling/no start is different though.

Looking to replace the positive and negative battery cables as I am sure they are both original. This is what I found, does this look correct?

2007 Yukon Denali, 6.2

Thanks!

 

[Campie]

Looking to replace the positive and negative battery cables as I am sure they are both original. This is what I found, does this look correct?
View attachment 460301
2007 Yukon Denali, 6.2

The main battery is on the passenger side near the firewall. There is a shelf for another battery drivers side in front of the fuse box but there’s no battery or cables there. Looking to replace the main battery cables.

Thanks!

 

[Bigdaddy88]

I have a 2007 escalade when i took it on a 13hr trip both times i stopped for gas it acted like it was loosing fuel pressure, filled up acted like it was flooded, it started took off 80mph for like another 2-3hrs when i pulled over on ramp for gas station truck died would not start at all, still had fuel though, so i let it sit for like 15 minutes an it started ran rough so i got a hotel room it was 11 at night couldnt keep going , i had a small handheld scanner code was for timing, morning at 8am went to auto parts bought a lucas for engine oil added it and drove back fine till last gas stop it started acting up again took to the shop and ordered timing chain kit ,oil pump,oil pickup tube, cam sensor, water pump,replaced all dealer parts, after that no more problems idk u might have same problem oil pump gets weak and looses pressure, that was my fix.

 

[Dustin Jackson]

@Campie The part number I have for the negative battery cable is:

22846471​

It’s distinguished by its electrical connector and 3 connections: battery, front of passenger head, under the radiator support frame are

 

[ckeister]

Sorry I havn't had time to read this whole thread. But are you sure its fuel and not ignition? Our truck did the exact same thing you are describing. After two tows and starting up the next day, throwing some parts at it, and wanting to blow it up, it turned out to be the ignition switch. Literally everything electrical on that thing runs through the ignition switch. I've learned that the more computer controlled a vehicle is if the problem occurs when the vehicle is hot or under a load, I think ignition/electrical before fuel. I understand the fuel delivery is all electronically controlled so I hope you understand what i'm trying to say.

Check engine light come on when this happens? Any codes getting spit out?

 

[Campie]

I have a 2007 escalade when i took it on a 13hr trip both times i stopped for gas it acted like it was loosing fuel pressure, filled up acted like it was flooded, it started took off 80mph for like another 2-3hrs when i pulled over on ramp for gas station truck died would not start at all, still had fuel though, so i let it sit for like 15 minutes an it started ran rough so i got a hotel room it was 11 at night couldnt keep going , i had a small handheld scanner code was for timing, morning at 8am went to auto parts bought a lucas for engine oil added it and drove back fine till last gas stop it started acting up again took to the shop and ordered timing chain kit ,oil pump,oil pickup tube, cam sensor, water pump,replaced all dealer parts, after that no more problems idk u might have same problem oil pump gets weak and looses pressure, that was my fix.

Trying not to throw so many parts at once but yes, oil pump, cam and crank sensor, etc are n the list! Glad yours is running well now!

 

[Campie]

Sorry I havn't had time to read this whole thread. But are you sure its fuel and not ignition? Our truck did the exact same thing you are describing. After two tows and starting up the next day, throwing some parts at it, and wanting to blow it up, it turned out to be the ignition switch. Literally everything electrical on that thing runs through the ignition switch. I've learned that the more computer controlled a vehicle is if the problem occurs when the vehicle is hot or under a load, I think ignition/electrical before fuel. I understand the fuel delivery is all electronically controlled so I hope you understand what i'm trying to say.

Check engine light come on when this happens? Any codes getting spit out?

No lights, no codes, just time before it starts and is fine.

 

[Campie]

Trying not to throw so many parts at once but yes, oil pump, cam and crank sensor, etc are n the list! Glad yours is running well now!

We do have the low oil also so pickup o-ring and/or oil pump is also in the thought process.

 

[ckeister]

No lights, no codes, just time before it starts and is fine.

Thats exactly what ours was doing.......

 

[Campie]

Thats exactly what ours was doing.......

We have a camping trip next week so it will be a good test of the few, simple things we’ve done. Here’s the list so far:

MAF and filter
Battery cables and cleaned the grounds
PCV
Vapor Canister Purge Valve
Fuel pump - last fall, did not help!

We’ll keep you posted!

 

[Campie]

We have a camping trip next week so it will be a good test of the few, simple things we’ve done. Here’s the list so far:

MAF and filter
Battery cables and cleaned the grounds
PCV
Vapor Canister Purge Valve
Fuel pump - last fall, did not help!

We’ll keep you posted!

Ok, not fixed… correction to the list: battery cables and PCV not replaced yet but grounds cleaned.

Just did it again but this time with a full tank. Pulled off the highway, stopped in traffic and just died. No lights no codes no nothing. We were able to check for fuel at the shrader valve on the fuel line and it looked fine - no air, no sputtering, just fuel out of the valve. It cranks just fine and tries to start, but can’t stay running. This time unfortunately, the battery died before it started. A wonderful couple stopped and gave us a jump and it started right up. Could it be the battery? Maybe the battery is not the correct battery for the vehicle or is a little weak? Yikes!

 

[solli5pack]

It requires fuel, air and spark to run. Gotta figure out which one is missing when it's not running. Im not sure I would trust your fuel pressure test by just seeing if fuel comes out of the valve when pressed. A fuel pressure gauge would tell a lot.

 

[Campie]

It requires fuel, air and spark to run. Gotta figure out which one is missing when it's not running. Im not sure I would trust your fuel pressure test by just seeing if fuel comes out of the valve when pressed. A fuel pressure gauge would tell a lot.

Yep, I’ve seen where folks here attach a gage to the Shrader valve and route it out so it readable when running. Would a bad or weak battery cause this?

We were pulling our little camper on the highway and power was great - up until it just died.

 

[rdezs]

Actually yes, a failing battery can cause this, along with all sorts of other issues. It's a roll of the dice to predict what it will react with. Simple enough, most auto parts stores will load tested in the car for you. They will also check your charging system for free.

I can't remember all the previous six pages of posts..... Did you verify the brake booster doesn't have a huge vacuum leak internally?