'07 Denali hot stall?

[cvdaddy]

I have a 2007 Yukon XL Denali with 136,000ish miles. On hot days (85+), the engine will stumble and sometimes die at stoplights. Seems to happen when the tranny temp is over 200. If it does die, it won't restart for 45 minutes. The starter almost sounds like there is no compression in the engine (fast). Truck runs fine all winter, but when it starts getting hot... Did this last summer too. I've had the injection cleaned at a couple different places. Last one did the BG 3 part. Week before last, I sprayed of the throttle body and MAF using the correct CRC sprays. I usually run a K&N, but threw a paper one in to see if it helped.
Has anyone heard of anything similar?

 

[Shelbya]

Doesn't really sound fuel related. Sounds like a temp sensor or the like. Either an engine temp or tranny temp.

 

[mbbaker900]

haha down here in Texas 85 is considered a cool day

 

[GM Customer Service]

Were you planning on having the vehicle diagnosed? Keep us posted when the issue has been taken care of.

Caron, GM Customer Service

I have a 2007 Yukon XL Denali with 136,000ish miles. On hot days (85+), the engine will stumble and sometimes die at stoplights. Seems to happen when the tranny temp is over 200. If it does die, it won't restart for 45 minutes. The starter almost sounds like there is no compression in the engine (fast). Truck runs fine all winter, but when it starts getting hot... Did this last summer too. I've had the injection cleaned at a couple different places. Last one did the BG 3 part. Week before last, I sprayed of the throttle body and MAF using the correct CRC sprays. I usually run a K&N, but threw a paper one in to see if it helped.
Has anyone heard of anything similar?

 

[cvdaddy]

It's not throwing any codes. I've had the Chevy dealer hook it up to the computer and nothing is showing. Even when it has happened, the check engine light has not come on. If I could get it to happen on the dealer's lot, they said they might be able to read something.
Any 6.2L owners with anything similar?

 

[emann_01]

Trans temps over 200 sound high especially when not towing

 

[carlduke]

Did you ever find an answer to your problem. I have a 2007 Yukon Denali and am experiencing similar problems. In high temperatures +85 degrees after the car has been driven for 20 minutes or so, if it is put into park it will stall. It will then have troubles restarting (as though a crank position sensor) or something like that is not working. It will try to turn over but it is almost like it is not getting enough fuel for some reason.

After sitting for at least 10 minutes, it will generally restart after a few attempts and then we won't have the problem again. No codes, never an error. It happened once with a very high transmission temp, but other times we were well under 200 degrees on our transmission temp.

Also, have you noticed any fuel gauge discrepancies?

Thanks...any response would be GREATLY appreciated. We have seen two dealerships and neither of them have been able to help at all.

Carl

 

[cvdaddy]

I replaced the battery and haven't stalled since. The last time it stalled, I ran the hazards for about a half hour and tried starting numerous times and the battery went dead. I thought that was pretty weak, so I took the battery in to O'Reilley's and had them test it. They tested it and it said it was good and needed a charge. He charged it and tested it again and it said it was good, just needed a charge... He did it a couple more times and warrantied the battery. I put the new one in and it hasn't stalled yet. It's felt like it was close, but didn't. I don't know if I 100% agree that the problem is solved, but no stalls yet. It sucks to have a $50000 truck that you're afraid is gonna die in traffic.

 

[GM Customer Service]

carlduke,

I am sorry to hear that you are experiencing this issue. Did you try installing a different battery as cvdaddy stated?

Thank you,

Elizabeth, GM Customer Service

 

[cvdaddy]

Late Update:
End of August it stalled again at a light. This time started back up on 4th or 5th try. Drove about a 1/4 mile and cut out while driving. Coasted into parking lot and had towed home. Dropped the tank and replaced the fuelpump. Hardest part was trying to get most the gas out before dropping it. Has worked great for 2 months.
Looking back, I think all the stalling was leak back at the pump.

 

[AZSCTACO]

Late Update:
End of August it stalled again at a light. This time started back up on 4th or 5th try. Drove about a 1/4 mile and cut out while driving. Coasted into parking lot and had towed home. Dropped the tank and replaced the fuelpump. Hardest part was trying to get most the gas out before dropping it. Has worked great for 2 months.
Looking back, I think all the stalling was leak back at the pump.

My fuel pump went out at 90K miles on my 07 Tahoe. Mine never stalled out but I did experience the "extended crank".

 

[snaward]

Hot Engine Stall with 08 Denali XL

I have a 08 Denali. After driving for extend period, we pull up to a stop and the engine idles rough dies. Will restart after awhile. So far it has happend 4 times. First time it restarted after a few minutes. After the second it was towed and the dealer replace the throttle body (we were stranded out of town waiting for it to be fixed). After third time (it restarted and we got home) dealer cleaned some connections (said it was related to grounding). Forth time the car did re-start and we were able to get off of the hwy and into a parking lot. We let it cool off for about an hour while we had lunch. The next day we came back home (~200 miles) with no problems. The car is at the dealer again to see if they can find something. But every time, when the motor dies, it has the same symptons of not restaring until it has cooled down some, it sounds like it is not getting fuel, and you hear a "gasping" sound at the end of the attempted start. The car has 62000 miles. Events 1, 2 & 3 happend in July 2011 (+90 deg F). Event 4 happen in Dec 2011 (~70 deg F).

 

[edgaranah1]

Thermostat? maybe.


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[stevek]

Trans temps over 200 sound high especially when not towing

That sounds REALLY high especially considering that the Denali's all have aux tranny coolers

 

[BilliYo]

Anyone still around & figure it what this issue is? I have the same thing going on with my 07 Denali.

 

[cdc2016]

Hey guys...Did anybody resolve this issue. I have a 07 Denali with the same issue. When I drive the vehicle for 20-30 minutes then it dies when I come to stop. It will take anywhere from 10-20 minutes until I'm able to start it again. No codes on the ODB reader and no lights on the dash..
I replaced the throttle body, battery, alternator, fuel pump relay (fuse). Still have the issue..Any help will be greatly appreciated.

 

[kbuskill]

Hey guys...Did anybody resolve this issue. I have a 07 Denali with the same issue. When I drive the vehicle for 20-30 minutes then it dies when I come to stop. It will take anywhere from 10-20 minutes until I'm able to start it again. No codes on the ODB reader and no lights on the dash..
I replaced the throttle body, battery, alternator, fuel pump relay (fuse). Still have the issue..Any help will be greatly appreciated.

Wrap your fuel lines up near the engine and your fuel rail with a heat shielding wrap, like the foil backed fiberglass starter wrap, and see if that doesn't fix your problem.

The 6.2L runs pretty warm and causes the fuel in the fuel rail to vaporize which causes the stalling issue. Letting the engine cool down lets the fuel rail cool down and the fuel inside to return to a liquid state and the truck to run again.

All though I don't recommend doing this due to potential fire hazards with fuel on a hot engine.... There is a plastic cap on the fuel rail and under that cap is a fuel pressure test port that has a shrader valve like a tires valve stem, if you pressed this in while the truck is stalled, and released the vaporized fuel, it would probably start.

Keep us posted.

 

[cdc2016]

Thanx for the input kbuskill..Since my last post I replace the crank positioning sensor also..Today my wife took the car to go from VA to NC and the car died at the first gas station.
A few weeks back (before I replaced the crank sensor) I drove the car for 35 mile to an airtport and when I slowed down/stop to get the parking ticker before the gate the car died there. I checked the rail as suggested on another post and it sprayed gas all over the place. I did not see any bubbles or notice low fuel pressure (off course I'm not an expert and I did not have a pressure meter with me). I messed with the fuel rail when the car was actually dead and it wouldn't start. I sat there waiting for about twenty minutes and the car started again. I've read somewhere else about the vapor issue but I didn't do anything about it yet. I guess that will be my next fix if she makes it back home with the car (over 400 miles away now).

 

[cdig]

Anyone have any luck figuring out this issue? I just had a similar issue in our 08 Yukon XL Denali... after towing our camper for ~20 minutes in fairly hot weather, came to a stop light and the truck idled down to ~400-500 rpm... had to feather the gas to get it moving when the light turned green, and got a bit of a shift flare in 3rd I think.. ran ok on the hwy, started fine after we stopped for fuel an hour later, but died in the yard after almost coming to a complete stop... wouldn't start for 30 minutes, then fired up and runs fine.

 

[kdenneny]

Ok, I too have been chasing this for about a year. 07 Denali, 6.2, 150k miles. When towing our 30' RV (~7500 lbs.) in temps over 85-90 at highway speeds, stalls when you stop (unless I keep my foot on the gas, and keep it above ~1000 rpms). Starts and runs fine after ~30 minutes.

After reading countless internet post, I have tried:

cam sensor.
VVT magnet (the one outside the cover, not the actuator, although I bought one)
switched back to 5W-20. I was running 10W-40, but read this could be an issue.

After this, it acted exactly the same first trip at ~88 degrees after 45 minute tow. It does feel like vapor lock, I thought this the first time it happened.

Another post said this worked, so last week I wrapped the fuel rails with heat shield, and the line down past the firewall. Took it to the beach towing this weekend, stalled on the way home. 90+ degrees out, coolant was up past the 210 mark (at about 1:00) trans was at 212. No codes, never any codes. Popped the hood, hit the schrader valve on the rail, no vapor, just raw fuel for 10-20 seconds (I didn't have a gauge, but plenty of fuel there, the key was off so the pump was off). Still no start. Went to RV and got ice, PACKED the fuel rails in ice. Poured cool water as best I could down the back supply fuel line. No start. Sat for 45 minutes, tried starting it every 3-5 minutes. Finally started, got home (40 minutes without issue).

This is the most frustrating issue I have ever had, because it is hard to duplicate without a truck full of family, and something heavy in tow.

Any insight you folks have would be much appreciated!

I think next I will pull the throttle body off/apart.

I do not think the fuel pump is the issue, as some suggest, need more fuel to haul the RV at 70 than to idle at a light. This thing will pull the RV all day as fast as you want. Just don't stop at a light!