The service manager at my dealership says my 2011 Silverado 4.8 liter came from the factory with the GM synthetic in it, which it probably did. And she swears it is as good for Chevy engines as Mobile One. I asked her why my 2004 Vette came with Mobile One if the GM stuff was "just as good". She didn't answer. But I am getting old and tired of arguing with those folks. You don't want to get angry with you or they won't do such a good job with the warranty stuff.

 

My oil cap says mobil 1 synthetic.

 

This post is ancient....let me blow the dust off of it and pick some minds...
Today while driving my 2010 sierra z71 just shut off... Had to turn the key to the off position to start again. Then the service hybrid system light came on in the information center.. no check engine...
I get 3 miles down the road and it shuts off at a light. Turn the key off and then back on and she fires up only this time a CEL and service hybrid system light....I'm a little nervous, i haven't even had it a year. Thinking about trading it for a diesel before it leaves me stranded.... Anyone have any ideas? This seems to be the most recent posts on hybrid Sierras...just hit 111k

 

Mine was having trouble with rough transition when taking off when engine was not running. Had a couple of hybrid codes stored. I went to every connector in the aux pump control and module and pulled them apart and reseated them. Knock on wood been good for 20k miles. Point is a lot of issues both hybrid and normal cars are related to connections. Try that first. Or if you decide to sell your pickup let me know, might like a fuel efficient pickup to replace my thirsty one. seems like we drive the Yukon everywhere cause it uses so much less gas. (Comfy ride too)

 

09 Tahoe with 105,000 to dealer for steering gear and oil change. Now at 108,000. Oil pressure dropped to 20. Usually runs around 60. Started hearing lifters, put in a quart of Lucas, pressure back up, not more lifters. Headed down the road and an hour into trip, lifters again ticking and low oil pressure warning. Towed to dealer, lifters or possible motor replacement. Waiting to hear what they recommend. It is hard for me to stomach. It was just at the dealer for an oil change. My oil life was 42% according to the vehicle. Chevy must know there is an issue with this by now.

 

We don't follow the owner manual recommendation for oil change interval any more. We have gone back to every three thousand miles, even with the blended synthetic they recommend. We did follow the recommended schedule until at 88,976 our 2008 Tahoe Hybrid threw a check engine light that said low oil pressure and stop engine. We paid $1,013.14 an intake manifold, oil pressure sending unit, gasket kit, labor and oil and filter change. Parts were $579.57; labor was $422.95; misc. $6.56; insurance -$50.00; and sales tax $54.33. Seemed to fix things till at 89,016 miles we had to have a new valve cover and gasket and new plugs for total cost of $457.97. No new problems since then and we now have 126,000+ on the clock. Again, we change the oil and filter every 3,000 miles since then. It runs well. Still gets 21+ mpg consistently. Wife drives it and when school is in session (she still teaches part time), she puts minimum of 40 miles commute five days a week. But she often goes to see the grand kids 37 miles away and she can't resist a trip to OKC, 90 miles away, at least every couple of weeks. She is a very gentle driver and hardly ever pushes it. She has never even scraped the low front valence on a curb, much better than I would have done. The valence looks brand new. (I can send you a copy of the work order if you wan to see it. Also a schematic of the parts used by part number so you can see what we replaced.)

 

I bought my 08 Tahoe last week used with 125,000 miles on it. No idea what all is about to go wrong with it, but I'm having almost the identical issues. One door lock actuator is about to go out, I have a cracked dash, get around 19.1 MPG, get the occasional jerk and shudder (but not too bad) and the display seems to cut in and out randomly. Otherwise, smooth ride, and lots of fun.

 

Hello tiktok4321.

Getting close to 130,000 on the odo. No new issues other than a very very slow oil leak somewhere under the engine. I did not even notice it until the last oil and filter change a couple of weeks ago. A day after the service, I noticed a spot on the floor and figured ti was a leaking filter or the drain plug not tight enough so I took it back to the service center for a check. It appears they spilled some oil when they took off the used filter and it fell on the frame near the filter and was falling on the garage floor. However, while under the truck looking at the leak area, we noticed some oily grime on the bottom of the block near the filter. I put a piece of cardboard where I found the leak in the first place but have found no more drops of oil anywhere. I have also been checking the oil level every few days and have noticed no drop in the dip stick level. Other than that, I have no new issues other than a corroded battery post for the 12 volt battery, under the hood, that I need to work on again. Guess I did not get it all cleaned up and protected a month ago when I cleaned it the first time. Am somewhat apprehensive about disconnecting the battery again because it took about a day for all the systems to get back to normal after losing juice.

 

tiktok4321,

In terms of the jerk and shudder, here are comments from another post: https://www.greenhybrid.com/forums/f...75/#post261521

Re: While stopped, RPM shot up to 5k and down, now shifting problems
Quote:
Originally Posted by vanZylin View Post
Any updates? We have a 2008 with about 150K and it's sporting the same symptoms. Mostly go to take off, engine revs higher than pressure on gas peddle. Truck moves, but feels like it's slipping. Then starts to catch, rpms down to expectation. Ocassionally get herky jerky start or stall. No code. Seems to do this more when hot and driven for a lot of small trips - 2 to 3 miles. Has no bearing if engine is warm. Restart and drive in M4 seems to do the trick.

We've had the engine, transmission and control panel checked by dealer. Cannot reproduce on demand. At this point, it feels like a bad sensor feeding bad information to the computer and thus it can't decide how much of either electric drive or engine drive it needs.
I do have an update. I apologize for not having posted it on my original thread.
Here is the link to my comment. https://www.greenhybrid.com/forums/f6...09/#post260057

This is what I said, Its not good. Please refer to the context in the thread as I follow up to some of the other comments following my reply.

"I wanted to chime in. My 08 HyHoe was also showing the symptoms of your original post. I had no check engine lights or alerts. The dealer said the Hybrid battery was within tolerance. So i called a local reputable hybrid shop. He connected his computer to the Hoe and in is opinion GM has defined the operating tolerances to give the illusion of long battery life but sacrifices the drive quality the worst the battery gets.

I decided to replace all the cells with a new batch of current gen ones. He ran diagnostics on the cells that were in my Tahoe and they were all around .9Wh. New they are to report 6-7Wh per cell. So they were not bad per-say, just worn and through with their expected life.

So what does GM consider "Within Tolerance"? After installing the new pack, Its a whole new vehicle with no more hesitation or any of the annoying driving issues as before.

I paid 2200 for new cells and labor. I recommend it if you are driving an 08 as it will get worst. I am also having the shop modify the fan speed so as to provide more airflow to the batteries constantly."

DirtRunner21,

Many Thanks for the answer. We opted for just replacing the battery so hopefully we can get another 100,000 to 150,000 out of the vehicle.

So... the jerking and stalling was getting to the point that something had to be done. GMC dealer quoted $4,600 for a new battery pack installed. I live in the DFW area and found a shop that specializes in Hybrids (thanks to your suggestion). They quoted $3,300 installed. We're at 165,000 miles and love the truck as well.

Glad I did it. Solved all problems. No stalls, no jerking, no slips.

 

First of all, let me say "THANK YOU" for quick responses. There just doesn't seem to be much activity on ANY HyHoe forum any more. Not too surprising considering their age and discontinuance. However, I think there is going to be a new breed of cheapskates who are going to start finding deals on these (I paid $10,500) and starting a new interested in the 2nd hand market.

VanZylin, I have seen those threads and they are very relevant and informative. I'm wondering if single cells can be replaced, and where to even find a new battery. The battery pack part number is obsolete and I can't find a replacement p/n. I don't need one, yet, just wanting to be prepared.