Rattle tied to low rpm load.

[brodeyo]

I have a 2012 Lt tahoe with 4k miles on it. Since the day i got it its had a rattle at low rpm while going up gentle grades in the road. Ive had it looked at by two dealerships and one said it was normal and the other said they couldnt hear it. Its driving me crazy and isnt a sound a $50k vehicle should be making. I'm seeing a lot of folks on the internet with the same problem but not seeing any answers.... Anyone have any answers out there?

Frustrated first time GM owner....

 

[jweezy]

Listen I have a 2007 LT3 with the 5.3 AFM bull cra p. Don't know if the AFM has anything to do with the rattle. Most likely not. I had an oil consumption issue so Dealership did free Oil Pan deflector and new valve cover on the drivers side. Still had oil consumption issue so they replaced all pistons and rings and had the heads shaved. I had a rattle when it was new, and still after the rebuild. I have 62,000 on it and yes I hate the load rattle as well. I always listen to something on the radio just to drown out that load rattle. I am guessing it's valves. If you or anyone else has the fix let us all know thanks. I'd be willing to pay the 5-600.00 bill just to fix this rattle!

 

[brodeyo]

Yep. Ive got the noise recorded on my phone for the techs to listen to at my 5k service. It sounds like the pulleys, but ive been told those are fine...

 

[CodeB4U]

Make sure you oil dip stick tube isn't vibrating and also your transmission tube dipstick. I've had a lot of complains about a rattles. Mostly have been that.

Just rev slowly a few RPMs at a time till the rattle happens...if it does.

 

[brodeyo]

Good to know. Unfortunately my rattle happens under load. No rattle in park with rpms. I will pass this info to tech though.


Upadate: wow didnt realize how long those dip sticks were. Thoses definitely could be the culprits. But not sure best way to test.... Do they sell caps i can replace the dipstick with?

Thanks

 

[RFoster130]

I have a new 2012 LT and haven't had this issue yet. If it comes up, ill let ya know. Where in Cincy are ya brodeyo? Im just about 15 miles south of the river in KY.

 

[CodeB4U]

This is from the service manual from GM about the bulletins.





The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:

Some customers may comment on a rattle, buzz, tick, or vibration type noise that appears to be coming from the center of the dash. Root cause may be the transmission dipstick tube contacting the front of dash (cowl). If the transmission dipstick tube is too far rearward, it will contact the front of dash and vibrate, buzz, etc. causing the noise to sound like it is inside the dash area.
Recommendation/Instructions:

To correct this concern adjust/bend the transmission dipstick tube away from the front of dash/cowl to provide additional clearance. When inspecting or adjusting the transmission dipstick tube it may appear to have enough clearance with the vehicle stopped. Verify that there is enough clearance to allow for powertrain movement during acceleration and deceleration. Inspect for contact while shifting between drive and reverse.

Note: If the dipstick tube is found to be broken or cracked on trucks equipped with the 6-speed 6L80 (RPO MYC) Automatic Transmissions, please reference the latest version of PI0522B for repair information.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.


WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

 

[brodeyo]

Well, sorry I forgot to update the forum... To date, I've been in three times and the dealership is unable to hear the sound...even though I still hear it every time I drive it. It's not a dipstick issue. It could be the oil, fuel or coolant lines vibrating together... Just tonight I sent Chevy an email...We'll see if they get back to me.

 

[jweezy]

rattle under load turns out to be inferior lifters

Well, sorry I forgot to update the forum... To date, I've been in three times and the dealership is unable to hear the sound...even though I still hear it every time I drive it. It's not a dipstick issue. It could be the oil, fuel or coolant lines vibrating together... Just tonight I sent Chevy an email...We'll see if they get back to me.

Found out that the lifters GM used in these engines are inferior and rattle under load. They are not covered under warranty because they will state operates as designed. I have not taken mine in to ask because I know what it will say on the service sheet when I go to pick up. Yes I did awhile back take it in for service and reported the rattle under load and told them it was likely lifters or valves and they reported on the service sheet could not duplicate. Looks like I will be shelling out a couple hundred for new lifters and install myself with a couple a someday!

 

[thompsoj22]

I have a 2012 Lt tahoe with 4k miles on it. Since the day i got it its had a rattle at low rpm while going up gentle grades in the road. Ive had it looked at by two dealerships and one said it was normal and the other said they couldnt hear it. Its driving me crazy and isnt a sound a $50k vehicle should be making. I'm seeing a lot of folks on the internet with the same problem but not seeing any answers.... Anyone have any answers out there?

Frustrated first time GM owner....

i am loyal to MB and have spent an enormous amount of money over the past 10 years for german attention to detail and design, end result "reliability". it is sad that america dosent build a car worth $50,000. sorry to hear how you feel, check out the ML series. you wont regret a single day of ownership.:happy160:

 

[jweezy]

afm 5.3 oil burner,rough idler, rattles under low rpm load lifters

This is from the service manual from GM about the bulletins.





The following diagnosis might be helpful if the vehicle exhibits the symptom(s) described in this PI.
Condition/Concern:

Some customers may comment on a rattle, buzz, tick, or vibration type noise that appears to be coming from the center of the dash. Root cause may be the transmission dipstick tube contacting the front of dash (cowl). If the transmission dipstick tube is too far rearward, it will contact the front of dash and vibrate, buzz, etc. causing the noise to sound like it is inside the dash area.
Recommendation/Instructions:

To correct this concern adjust/bend the transmission dipstick tube away from the front of dash/cowl to provide additional clearance. When inspecting or adjusting the transmission dipstick tube it may appear to have enough clearance with the vehicle stopped. Verify that there is enough clearance to allow for powertrain movement during acceleration and deceleration. Inspect for contact while shifting between drive and reverse.

Note: If the dipstick tube is found to be broken or cracked on trucks equipped with the 6-speed 6L80 (RPO MYC) Automatic Transmissions, please reference the latest version of PI0522B for repair information.

Please follow this diagnostic or repair process thoroughly and complete each step. If the condition exhibited is resolved without completing every step, the remaining steps do not need to be performed.

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.


WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

The following diagnosis might not be helpful, just busting your chops it is Not this service bulletin they are inferior lifters/valves bottom line. Someday I am going to replace mine with after market. The top part of my engine has been rebuilt due to excessive oil consumption from the AFM system. Defector fix in the oil pan, Drivers side rocker arm cover, New Pistons/Rings, heads sent out to be shaved and I bet they used the old lifters. Yup they did still rattle on low rpm load. Other than that excessive engine oil consumption has ceased and that's what I went in to dealer for. They will not touch the lifters, could not duplicate and operates as designed the same old song and dance. But, it runs. It has never idled properly. It's like it is to lean and needs to have timing advanced plus 1. But, it runs so happy enough!:Whoa:

 

[brodeyo]

It's been documented!

Finally got around to filling a complaint with Chevy, as I was sick of taking the car to the dealership to no avail. The rattle always seemed to disappear when the tech and I were test driving.... They assigned the case to basically a project manager who worked with the dealership to assess the situation. We set up another time for me to drop the car off and get a loaner. Finally after two days, the techs heard the rattle (hooray, I'm not crazy). Now, they have to diagnose it. While I understand that the diagnosis may be difficult, I'm elated that the problem is actually documented. Hopefully I'll have an update soon.

I've seen on another forum that and individual had the similar issues with rattling on low rpm with load. His ended up being an exhaust leak... I'm hoping it's that easy. We'll see.

 

[jweezy]

inferior lifter/valves rattle under load

Finally got around to filling a complaint with Chevy, as I was sick of taking the car to the dealership to no avail. The rattle always seemed to disappear when the tech and I were test driving.... They assigned the case to basically a project manager who worked with the dealership to assess the situation. We set up another time for me to drop the car off and get a loaner. Finally after two days, the techs heard the rattle (hooray, I'm not crazy). Now, they have to diagnose it. While I understand that the diagnosis may be difficult, I'm elated that the problem is actually documented. Hopefully I'll have an update soon.

I've seen on another forum that and individual had the similar issues with rattling on low rpm with load. His ended up being an exhaust leak... I'm hoping it's that easy. We'll see.

Keep me posted, save your dealership print off many of us will need the info off it. Seems like when I go up a hill, give it a little gas putting engine under load just right the lifters RATTLE. My extended warranty is running out and I want to get this fixed. I already know what the dealership will say so I need to bring ammunition and most likely a video recording with audio to show incline with load makes engine rattle!

 

[SkiTahoe]

I just bought a 2012 Tahoe LT and have had the exact same issue. There's a rattle that seems to be in the dash that rattles when I hit the accelerator (mostly noticeable going around 30 mph). I'm wondering if anyone has had success in figuring out what it is. It's driving my wife and I crazy and we're really disappointed that our new Tahoe would have a problem like this.

 

[Metaldrgn]

That's strangely similar to the problem I'm having with my 03 expedition. It's only happening in drive and only going slow or from a stop and pushing on the accelerator slightly. I can't exactly tell if it's a grinding noise or vibration but I'm leaning toward grinding. Can you duplicate this by holding the brake and giving it a little gas?