I bought my Hybrid in August of last year and I drive over to San Diego just about every weekend. My Hybrid has about 32000 miles on it and I love being able to make San Diego on just under 3/4 of a tank of gas. I have the clunking noise as well sometimes when I accelerate. They had to replace the Brake pump in the first week that I owned the vehicle. I just had the 3rd oil changed and they did the recall thing with the transmission sensor...I am good with all of that.

It has finally heated up and the temps in Las Vegas are in the 112 to 115 degree range. Here is the new quirk.

My transmission seems to be engaging and disengaging intermitantly. When I was making a left across two lanes of traffic, got a opportunity gunned it and that big ole V-8 almost stalled. When I was pulling into the garage up my driveway, the front of the car entered the garage and then it let go when the mirrors cleared the door and the vehicle started backing up while in drive. I braked and tried to do it again. same thing happened. Took me three tries to get her in the garage.

Any one else have this problem?

 

mine acts kind of like it doesn't know what it wants to do....however if I accelerate hard but not flooring it IE 3/4 or a bit more throttle...it accelerates like a scalded dog! i think it has to do with the transistion between electric and gas modes. I just learned how to control it better and now passing anyone is a breeze. it is however counter intuitive to accelerate soft to make it accelerate it hard!

 

mine acts kind of like it doesn't know what it wants to do....however if I accelerate hard but not flooring it IE 3/4 or a bit more throttle...it accelerates like a scalded dog! i think it has to do with the transition between electric and gas modes. I just learned how to control it better and now passing anyone is a breeze. it is, however, counter intuitive to accelerate soft to make it accelerate it hard!

 

Wow, I though mine was high mileage with 20K. I drove mine through Vegas, brand new, in 115 degree heat, no problem.

It sounds like, and I'm not being a smart-*** here, that it is broken. Not totally, just that this is the first sign of needing repair. I think it is an awful coincidence that they just did work in the trans and now it is acting up.

Why do I suspect the trans? Well, the V8 is ****-near bullet-proof, a version of it being found in about every other V8 equipped vehicle on the road. So, it would be unusual to have a hesitation problem, but possible.
Second, you had problems at or near 0mph, where the electric motors should have been motivating the vehicle, even with the engine off. Unless your driveway is at a 45-degree angle, you shouldn't need the ICE to get in the garage. I would bet most of us have our ICE off in the driveway (mine is on for the first 3/4 as it is a very steep grade).

Take it in for a diagnostic, we won't be of much help on this one.

Please let us know the end of the story!

 

Actually had the Stableization light come for a while and I thought that we were looking at another brake pump. The light went off after the rig set for a while.

I took it right over to the dealer and explained the latest and that I couldn't leave the vehicle because we where going to be going out of town for a couple of weeks. He said that any time a light goes on, that event is stored in the computer so that would be easy to retrieve. The transmission symptoms sounded, to him, like something that is related to some bulletins that they have received about the batteries.

Personally I have a hard time strething across two different systems of a vehicle for one problem but I would love to be pleasantly surprised.

I appreciate any continued input and will post what happens at the dealer when I get back and have my Yukon spend a day at the dealership/spa.

 

I am having the same issue with my 2008 Yukon. I have only had it since the end of February. I live in Phoenix and the temps are definitely on the rise. Been to the dealership 2 times now and the only thing they can tell me is that it is the "extreme" temperatures. My thought is - why are you selling a vehicle that won't work in a climate that qualifies for "extreme" heat!!?? Today I was pulling into a parking space and the engine stalled out and I had to stomped on the gas to get it to crawl into the space. AZ lemon law is 4 times to the dealership. I have noticed a decrease in the gas efficiency as well...not sure what to do, but I feel like its only a matter of time until I get creamed in traffic when the vehicle decides to stall. I'd welcome any thoughts or if you can share your experience. Thanks!

 

Carmine and Sbliss,
Are your Tahoes, 4WD or 2wd, I am just wondering if this issue has to do with 4WD??

 

OK, I am going to check on the "Lemon Law" here in the state of NV and probably swing by the dealership and have a talk with the Service Manager about this problem and see if they have cross referrenced it with other states with temps exceeding 110+ degrees. I did notice that on this last take of gas that according to the on board computer, my MPG is down to about 15.6.
Sara, let's keep close on this, I think that this is a real concern and you know that someone will get hurt and it could be potentially very serious.
Jordan, my 2008 Yukon is a 2wd. first 2wd vehicle that I have owned in 20 years.

 

Thanks carmine

 

If you read my post elsewhere, I drove mine new, out of vegas, in 115 degree heat. it was bumper to bumper from the city line to the top of the grade. Four hours, bumper to bumper up a mountain and the temp gauge never moved past mid-sweep. Lots of Priuses on the side of the road at 3000'. I think it is more of a combination of heat and something else. Is the fan running on the battery pack? It should sound like the rear A/C is on, when it is off. This would be best to check at the end of a few miles and a nice long regen braking session. Come to a stop, and with the a/c off and the engine in auto-stop, you should hear a fan behind you. If not, the squirrel-cage blower could be bad. This would cause the pack to overheat and not produce the current that the computer is expecting from the pack.

Just a theory.