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Chevy Suburban/Tahoe Rough Idle and Stalling



  • All,

    2008 Suburban that has had a rough idle since 15k miles, now has 48. It will run rough when it sits in gear at a red stop or just in park, the Suburban shakes and drive me nuts. No lack of power with normal driving just when it is sitting. Taken it to the dealer multiple times and the first time the technician says "well it's a big engine and they vibrate." That's bull becuase I have a 95 Silverado that purrs like a kitten and runs smoother than my 08. Since it was under warranty they replace the motor mounts (not sure why) of course the issue did not go away. Had it in again and told them they need to find out what is wrong, they cleaned the throttle body. They said it was filthy and then said it runs so much better now come and get it! Well it ran exactly the same and when I went back again they told me to put a injector cleaner in the gas tank. That didn't do anything! Any ideas of what I could do to convince the dealer to actually fix the issue?

  • gmcustsvcgmcustsvc Posts: 4,055
    Good morning Ryan,

    Sorry to hear that you're having trouble getting the rough idle concern resolved. If you would like for us to follow up on this with the dealership, please contact us via email at (include your name, contact information, the last 8 digits of your VIN, and the name of your dealership).

    Sarah, GM Customer Service
  • Well... cleaning the Mass Air Flow sensor seemed to do the trick for a little over a month, but my Suburban is now stalling again. Almost got into an accident with a semi last week on the highway because of it. I cleaned the sensor again, but still stalling. Tried bypassing the sensor by unplugging it and it's still stalling. Every time after a stall, I just pull over, wait a few seconds, and it starts back up after a couple turns of the key. Not sure what else to try at this point.
  • We had the same issue with our 2008 Suburban that I posted a year ago. The rough idling, in our case, was caused by failing AMF lifters. We had to have all of them replaced + the throttle body assembly replaced. We continued to see high oil consumption on the engine. Eventually, GM agreed to replace the entire engine.

    Here's what I suggest before your warranty runs out. 1.) Tell the dealer you want a master mechanic assigned to your vehicle and have them run an oil consumption test and check the AMF lifters. That said, even after the lifters were replaced and the engine cleaned, we continued to have problems. 2.) Document everything, file a complaint with the NHTSA (if they get enough, they may have to have GM recall), and contact GM to open a case. 3.) Your master mechanic can help to make the difference if they truly believe you have an issue. GM customer service originally told us that they couldn't do anything else but it was our mechanic who eventually submitted the request for a new engine after our car had been in the shop 50+ days over the course of 2 years. Here's the bulletin information:
    #10-06-01-007: Active Fuel Management (AFM) Engine, Valve Lifter Tick Noise at Start Up When Engine Has Been Off for 2 Hours or More (Evaluate Noise and/or Replace Valve Lifters) - (Aug 13, 2010)

    Subject: Active Fuel Management (AFM) Engine, Valve Lifter Tick Noise at Start Up When Engine Has Been Off for 2 Hours or More (Evaluate Noise and/or Replace Valve Lifters)

    Models: 2007 Buick Rainier

    2009 Buick LaCrosse Super, Allure Super (Canada Only)

    2007 Cadillac Escalade

    Built Prior to April 1, 2006 with 6.2L Engine RPO L92 (These engines were built with AFM Hardware but the AFM system was disabled)

    2007 Chevrolet Monte Carlo

    2007-2009 Chevrolet Impala

    2007-2010 Chevrolet Avalanche, Silverado, Suburban, Tahoe, TrailBlazer

    2010 Chevrolet Camaro SS

    2007-2010 GMC Envoy, Sierra, Yukon

    2007-2008 Pontiac Grand Prix

    2008-2009 Pontiac G8

    2007-2009 Saab 9-7X

    Equipped with AFM (Active Fuel Management) V8 Engine (RPOs L76, L94, L99, LC9, LFA, LH6, LMG, LS4, LY5)

    Attention: This bulletin only applies to the AFM V8 engines listed above. It DOES NOT apply to Non-AFM Engines. If you are dealing with a Non-AFM engine that is experiencing a similar noise, please refer to Engine Mechanical > Diagnostic Information and Procedures > Symptoms in SI.


    Some customers may comment on an engine valve lifter tick noise that occurs after the engine has been shut off for at least two hours. The tick noise may last from two seconds to ten minutes.

    This condition may be caused by any of the following:

    • Aerated oil in the valve lifter body, resulting in the valve lifter being unable to purge the air quickly.

    • A low engine oil level or incorrect oil viscosity.

    • Dirty or contaminated oil.

    • A low internal valve lifter oil reservoir level.

    • Debris in the valve lifter.

    • A high valve lifter leak down rate.

    If the SI diagnostics do not isolate the cause of this valve lifter tick noise and normal oil pressure is noted during the concern, perform the following steps:

    Inspect the engine oil condition and level. Refer to Owner Manual > Service and Appearance Care > Checking Things Under the Hood > Description and Operation > Engine Oil in SI.
    ⇒ If the engine oil is more than one quart low, an incorrect oil viscosity is being used or if poor quality/contamination is observed, change the oil and filter.

    Note: Allow at least a two hour soak time between engine OFF and start up when evaluating the tick noise.

    Start the engine and evaluate the valve lifter tick noise.
    ⇒ If the valve lifter tick noise is still present, replace all 16 valve lifters. Refer to Valve Lifter Replacement in SI.

    Parts Information
    Note: A V8 AFM engine requires 8 AFM lifters and 8 non-AFM lifters for a total of 16 lifters.

    Part Number

    Non AFM Hydraulic Valve Lifter

    AFM Hydraulic Valve Lifter

    Warranty Information (excluding Saab U.S. Models)
    For vehicles repaired under warranty, use:

    Labor Operation
    Labor Time

    Valve Lifter Replacement - Both Sides
    Use Published Labor Operation Time

    Warranty Information (Saab U.S. Models)
    For vehicles repaired under warranty, use:

    Saab Labor Operation
    Failed Object
    Fault/Reason Code
    Location Code
    Warranty Type
    Repair/Action Code
    STM Labor Time

    Replace part, Depressor
    01 (Replace)
    Use Published STM Labor Operation Time
  • my 2009 suburban has similar problems.. It has 78,000 miles on it and was fine until about 75,000 miles. Then it started with the transmission not changing gears, remaining in low gear, traction control light coming on, etc. It first happened when my wife was driving it on an interstate and it did the same thing- went into low gear and would not change. It nearly caused her to wreck.
    We have had it to the dealer"s five times and still no change. After it sits for a while, it will run normal again for sometimes days but sometimes only minutes. The dealer said it was giving numerous codes and we replaced some electronic cables, etc. This did not fix the problems.
    The last 2 times, after the car was at the dealers for a couple of days, the problem resolved and they released it. However, the same problems start again once the car is driven for sometime.
    It clearly is not safe to drive and certainly unreliable. I have contacted GM but they are no help, Guess I have a lemon and will address that in a Court case.
  • We bought a 09 Suburban after I got T boned by a drunk driver in our 07 Tahoe that saved my life. We have 5 kids and a nanny to move around so needed the larger car. Unfortunately we have had many problems with it, firstly there are many clunking noises etc and the lifters make a lot of noise at startup and continue for a long time. Then my wife was on the way to school with the kids, fuel light came on so she was going head to gas station after dropping kids at school. She made it another 50' and it just died. Said there was still 50 something miles on it. Friends pick kids up and my wife walked home she went and got gas from home and an hour later it started with more gas. Fast forward to last night on the way to my daughters solo at big singing event it happened again. Car is now stuck on the side of the road 100 yards from the house gunna try and get it home then call GM. I'm thinking recall Chevy?
  • gmcustsvcgmcustsvc Posts: 4,055
    Have you gotten in contact with our Customer Assistance Center already on this? We're sorry that this concern has interrupted your day to day schedule a few times!

    Sarah, GM Customer Service
  • Yes the tow truck just picked it up, just with only 27K miles it surprising.

  • gmcustsvcgmcustsvc Posts: 4,055
    Good to hear, Jay. Keep us updated!

    Sarah, GM Customer Service
  • Just picking up now, they said it just ran out of gas with 1/8 of a tank left? Low fuel went off then 50' later stopped. Something is wrong with that
  • alanrsalanrs Posts: 25
    The systems for indicating driving range in modern cars are pretty remarkable, but they are not infallible. My wife's '09 G6 has the same type of readout, which shows how many more miles of driving should be available before the car runs out of fuel. Sometimes she has pushed it pretty far, so that the display read less than 20 miles. Perhaps it is because I know how those systems work, and that they are subject to some error, that I grimace every time she mentions how far she pushed it the last time.... ;)

    First it is best to understand that fuel tanks in most vehicles are shaped more like irregular covered skillets or rectangular sauce pans than a Big Gulp cup. The latter is smaller at the bottom than the top in part so that it can be more completely emptied via a straw, and the overall "footprint" is also very small when compared to the cookware. Even if tipped a fair amount to one side, very little liquid will remain if the straw reaches the bottom. Not so with the pans. A LOT of liquid would not be accessible unless the straw happened to be on the low side of the tilted pan.

    And so it is with fuel pickups inside of tanks. In the early days of automobiles, the gas might have been drawn from what resembled a drain, and virtually all of it could be emptied out. Modern cars have the fuel pump inside the tank for several very important reasons, and they are pretty universally inserted through and suspended from an opening in the top of it. Most fuel pickups are attached to the pump and have a filter at the inlet to keep out larger debris.

    Visualizing that type of system, it should be easy to understand that all of the fuel inside the tank cannot be accessed. Add in manufacturing tolerances in the tank and the length of the pump assembly to put the pickup even further from the bottom, and the inaccessible amount grows. Then add in a slope, such as a crowned or hilly road, or an inclined driveway, and there might just be a LOT of gas which cannot be drawn into the pump in certain circumstances.

    (As a side note, many competition vehicle fuel tanks incorporate a flexible and weighted pickup which follows the fuel according to lateral forces during racing. That way the pickup can get to virtually all of the fuel, as long as the car is being driven hard. A "caution" lap might save fuel consumption, but not get the pickup to where the fuel is. Such devices are not practical for street cars, where the forces are so much lower, and long-term all-weather reliability is essential.)

    The senders for fuel level are virtually all attached to the pumps. They are made up of three basic components: Float, arm, and sensor/sender. Roughly, it looks like the float in a standard toilet tank, on a smaller scale. While the gauges in the dash from vehicle to (same type) vehicle might be very uniform in how they process data from the sender, the electrical signals sent can be substantially different, even between cars nose to tail on the assembly line. Tiny variances in the buoyancy of the float, or the shape of the arm, or how it attaches to the electrical component can show up as notably dissimilar indications at the dash board.

    Among the cars I have owned in 4 1/2 decades of driving, the fuel gauges all behaved differently. On my Suburban, after I changed the pump/pickup/sender assembly, the reading at the gauge did not display in the same way. I was not surprised by that. One car might stay on the full mark for nearly a hundred miles, then slide quickly to the half mark over the next 40. Another could start dropping within the first 15 miles, and go down gradually, but seem to accelerate when the needle approached the 1/4 mark. Two identical cars might appear to have gauges which operate the same, or they might work a bit differently. Some fuel level indicators may be Very accurate, in direct correlation to the amount in the tank. Certainly, that is the engineered/designed goal. But of all of the systems in cars, it is likely the least consistent.

    So, back to the "miles left" readout on the dash.... That figure is a computation, based on historical calculated fuel economy stored in the car's computer, miles traveled since fill up (reset), and reading from the sender. After slogging through the verbosity above, it should be obvious to readers that such systems cannot be perfect, and may in fact have notable variances, without being truly defective. Circumstances might have one car out cold and stalled with 50 miles still shown to be available, while another car might keep going 20 or 30 miles past the zero point. It is the nature of such systems at this point in time. The possibility of a car sucking only fumes from the tank at exactly the point when the display goes from 1 to 0 is remote indeed.

    What it comes down to is that drivers have to be familiar with their cars. Everyone should know the gallons capacity their fuel tank. If the gauge is reading no lower than 1/8, but it takes 28 gallons to fill up out of a total volume of 30, then it should not be run that low. Certainly, if the same reading occurs and only 22 gallons will fit, then there appears to be a reasonable indication that the needle could sit on"empty" for a while before the supply actually got near that point.

    Motorists should also be reasonably sure what their vehicle gets for fuel economy week in and out for normal driving days. (vacations, and trips in general will be higher). That figure is best derived by using the trip odometer to keep track of miles between fill-ups, and dividing distance traveled by gallons consumed to get MPG. The "actual" usage might differ by several points from the computer calculated figure shown as part of the display. If someone's Yukon Denali (26 gallon tank) gets 14 MPG average to and from work, etc., then they should realize that anything beyond 300 or 310 miles since filling could be skating on thin ice, no matter what any gauge or display indicates.

    I hope this does not come across as a rant... :D
  • gmcustsvcgmcustsvc Posts: 4,055

    I know that alanrs gave a very in-depth description of accessible fuel - aside from the vehicle being out of gas, how is everything operating? I'm wondering if a fuel level sensor is having troubles.

    Sarah, GM Customer Service
  • I have been a loyal Chevy owner since 1997 and have been very happy with my vehicles, until now. I am in disbelief that I have a car that has ONLY 66,000 miles on it and I can't drive it because I am worried about it stalling as I travel the highway. It has been at the dealership for 2 days and all they can tell me is that the codes it is reporting are not related to the engine stalling. They are unable to determine any problem to fix. The only way they can better understand the problem is to keep driving the car and see if it stalls on them. Will they keep my car indefinitely? It has happened to me 2x now, once on Christmas eve (while we were traveling with my daughter who was just out of the hospital) and once on January 14th. Who knows when it will happen again, I can't leave my car at the dealership indefinitely and I am too scared to drive it until it is fixed. It seems to stall randomly; the first light to come on is the stabilitrak light and then I realize the engine if off and I have no steering or brakes. VERY SCARY. Both times I was traveling at appx 45 mph. The CAM sensor was replaced in 2011. The fact that the reported codes do not tell us what happened seems to be a problem in and of itself, to me. I am now making payments on a worthless vehicle that I can't use and don't want to trade it in and pass the danger to someone else (although, I think that may be what happened to me). I am 1 month out of the powertrain and GM continues to politely remind me of that. But, this should not be a problem with car with 66,000 miles! Anyone else had similar issue? If so, how was it fixed? If GM can't determine a fix, I guess I will be contacting the NHTSA on this one. Please help.
  • gmcustsvcgmcustsvc Posts: 4,055
    Have you already contacted Customer Assistance on this, scaredtodriv? If not and you would like for us to check in on the transmission situation further, please email us at (include your name and contact information, the last 8 of your VIN, and a summary of the situation).

    Sarah, GM Customer Service
  • yes, I have contacted GM Customer Service. They are relying on the dealer to determine the problem. But, I will also send you all the documentation on this. I accepted the first time as a "one-time" deal, but I can't accept it now that it has stalled a 2nd time. It is unacceptable. This is a serious danger issue. I would appreciate any help you can give.
  • gmcustsvcgmcustsvc Posts: 4,055
    We'll look for your email, scaredtodriv. Just so you're aware, it may take a while for our system to kick it to us, and we'll be headed out at 4:30pm EST until Monday morning.

    Sarah, GM Customer Service
  • We have a 2008 Suburban, purchased new in 09, and this thread reads like a history of our vehicle. At 46k miles, the AFM lifter (after multiple rough idle complaints) finally went out. When it went, it wiped out a lobe on the camshaft as well. This was repaired under warranty, and all of the AFM lifters were replaced. We had to wait weeks for the parts to come in, leaving us without our vehicle. The dealership worked a rental through the local rental company though, that was helpful.

    I am the father of 5 daughters, and my wife and I need our Suburban. We live in rural Eastern Washington, and get a fair amount of snow, and no other vehicle fits the bill for our transportation requirements.

    Soon after the lifter failure, we began having oil consumption problems. Long story short, at 94k miles in August of 2012 (after dozens of trips to the shop), they replaced the rings and pistons. At that point in time, I voiced my concern that this engine had been torn down and rebuilt twice, and I was worried about future engine failures. I was reassured by the dealer that anything that happened would be covered under warranty since the motor had just been rebuilt. We purchased a $2k minivan to do the run-around miles in, and drove the Suburban only when necessary.

    Now, on 22 December 2012, with 106k miles on the odometer, the AFM lifter issue is back. This time, when the lifter failed, it "shattered" (according to the dealership), and cannot be removed from the lifter bore. Solution? I need to buy a new engine.

    I have been dealing with my dealership (who has been helpful and supportive), but they told me that they cannot fix this, it needs to be handled by GM Customer Service.

    The case was elevated on 9 January. I was able to talk with my district representative on 10 January, and he promised to call me on 11 January after he researched my case.

    After 15 attempts by me to contact my representative, zero returned calls from GM, I found out today that GM is claiming there is no known problem with the AFM lifters, and stated that I have never had an issue with these lifters in the past, so they will not do anything. I was also told that there is no one I can speak with above my district representative, but that his supervisor would listen to me complain if I wanted, once he got out of his all day meeting.

    I don't expect his supervisor to call back, since the rep couldn't even return my phone calls over 12 days.

    I have been a Chevrolet customer for many years, have owned nothing but Chevrolet trucks and SUVs in those years, as they met my large family's needs. My entire family (siblings, parents, etc) owns Chevrolet trucks and SUVs, and all of us are beside ourselves with the lack of support and service on a known issue with defective parts.

    I hope someone gets some customer service, because obviously, my family is not.
  • gmcustsvcgmcustsvc Posts: 4,055
    Please send us either your Service Request number (71-**********) or the last 8 digits of your VIN as well as a brief recap of the situation. We would be happy to check into this further.
    Sarah, GM Customer Service
  • Sarah,

    Since I am a new user, i cannot PM you. My case number is 71-1143118212. My contact phone number is in my case file. I have a 5+ page word document detailing the phone calls since this case was elevated that I will be glad to send you. I am available in my office (number in case file) from 0800 PST to 1600 PST daily, if I do not answer please leave a voicemail with a callback number.

    By the way, the 'scheduled' call time has come and gone, and I did not receive a phone call from the supervisor.
  • gmcustsvcgmcustsvc Posts: 4,055
    Thank you for sending me your case information, 08suburban! I am showing an open scheduled call to you today still - I'm not sure what the delay is but I will notify your District Specialist that you are expecting to be contacted by him/her.

    Sarah, GM Customer Service
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