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Pentastar vibration at 2000 rpm/60 mph

31K views 58 replies 26 participants last post by  mikeh1955 
#1 ·
I noticed lately on my 12 limited I get a resonating vibration at exactly 2000 rpm when going about 60 mph. I feel it in the gas pedal and the floor of the jeep. Anyone else experience this with their v6? It's like a pulsating vibration... Thanks

The jeep has 700 miles if that means anything..
 
#2 ·
Our company has a lot of 2011 and 2012 GC's in their fleet (all but one are V6's, I did drive the single Hemi also). I drove many of them on extended trips of several hundred miles, before buying my 2012 GC (I drive from Minneapolis to Chicago about every 2 weeks for my job). I noticed that the combo of QII and the 20" wheels/Goodyear tires, that practically every one of they had a faint vibration/humm that could be heard and felt through the steering wheel and pedals.

Based on this, I got the Q1 and 18" wheels/Michelin tires and have had no issues.

There are quite a few others in the forums with this issue. If you have the V6 and 20" tire package, you might want to have the dealer check the balance. The wheel weights are stick-on style and can fall off. Also, you might have your 4-wheel alignment checked. Best luck.
 
#4 ·
Ya I guess it is under light load. Just pushing the gas at exactly 2k rpm in top gear. I don't think it's a tire or wheel issue. It's too exact on speed and rpm. I have had wheels outta balance before and it is not the same feeling
 
#8 · (Edited)
I think this is what I'm experiencing as well but I'm leaning more towards the tire wheel combo. I have QII with 20" wheels and GY tires and I feel that they are very sensitive to road conditions and create a lot of unecessary noise at times. I get more of a hum / higher tire pitch type sound even on smooth pavement at times. I am going to have my dealer balance and then maybe swap with the 18s and test drive.

I also have a line on a set of 18" "X" wheels/tires that I may pick up pretty cheap and give them a try to compare.
 
#11 ·
Maybe the tires and wheels are balanced, but the alignment is off? There are forums posts indicating that a good 4-wheel dynamic thrust alignment fixed the problem. This might mean finding a local shop that specializes in this, rather than relying on your dealer. You need a shop that knows how to properly align a 4-wheel drive vehicle, particularly a Jeep. Dynamic alignment equipment will have compensation for speed and loading factors, where problems show up at higher speeds. And while you are there, have them do a computerized 4-wheel balance also.

http://dynamicwheels.com/wheel-alignment-tips

http://www.blnz.com/news/2008/05/13/TOTAL_4-WHEEL_ALIGNMENT_5514.html
 
#13 ·
I've a 2012 Limited 3.6, 500 mi. I get the pulsation (the rpms stay steady) as you mention right around 60 on slight or moderate grades as well, that increases in frequency up through 70. I've had it checked by the dealer who while unable to reproduce it, claims it's torque converter lockup, and it's a design characteristic of the vehicle due to gas mileage compromises, etc. There were no outstanding TSBs for my vehicle nor was it throwing any error codes. It was also described as related to 'ECO' mode, and going heavy on the accelerator and getting the car out of ECO mode should alleviate the problem - however, this didn't work - the problem occurs when I'm heavy on the throttle as well. I'm also rejecting the description that this occurs when I put the vehicle in a specific 'condition'; driving up a normal hill on the highway at nominal highway speeds isn't what I consider a 'condition' (I'm not exactly hammering the vehicle up Pike's Peak in a road rally. I've also read that under mountain driving conditions you should employ tow/haul mode (alas, I don't have that button/package)).

I believe this might also be described as on the forum as transmission shudder, but could be wrong on this, as I've not been in another GC other than the one I have.

Whatever the cause - on a 40K$ vehicle, with 290hp - this should not be happening - no engineering team would possibly foist this sort of design/compromise on the public.

There is at least one TSB for 2011 models for 'transmission shudder' requiring a software update that I've read varying reports in the forum here that ameliorates the problem, but doesn't resolutely solve it. The TSB is not applicable to my vehicle - I'm guessing my build date includes the updated software. Poking around the internet there's a lot of data that is being processed by the whole drive train system (pedal pressure, temperature, etc) so I'd imagine it's not quite so easy to get the software right for this given the electronic and mechanical components. Easy or not, it needs to be fixed.
This link ( http://www.wk2jeeps.com/wk2_transm.htm) is interesting about the transmissions in general (including the upcoming 8 speed tranmission that is described as fitting in the existing housing, so that may be the ultimate solution).


In any event - I'll be pursuing this issue pretty aggressively and will be having a drive with the technicians to demonstrate exactly how to reproduce the issue and ensure that they can reproduce it as well. We'll see if they start replacing drivetrain components.

Good luck to us all.
 
#15 ·
and mine is not a solid vibration...its like a pulsating vibration..only happens at 60 mph 2000rpm..havent felt it at any other time...im thinking its just a normal thing with the engine..
 
#17 ·
If the engine RPMs are steady, and there's a pulsation - it must be some other mechanical component. Also interesting is that it only occurs on inclines. One theory is it's the torque converter engaging and disengaging - unable to properly handle all of the inputs so it "pulses" back and forth. Drive any other vehicle in the price range - and then re-ask if this is "normal". It's not. Jeep/Chrysler will only address this if their attention is brought to this.
 
#18 ·
If the engine RPMs are steady, and there's a pulsation - it must be some other mechanical component. ...
The VVT system (part of the engine) isn't static at a given rpm. Valve timing is changed in response to several factors, including load.

The transmission and components (developed by Mercedes) are used on many other models with different engines. I'm not aware of complaints about those.
 
#20 ·
I have the exact symptoms described by the OP - some type of harmonic noise when the RPMs are 2000-2400 going about sixty and under a moderate load (but not enough to shift the transmission down a gear). It's definately rhythmic and slow. I will report the issue using the link above. I've had the issue since new (early Feb) and still have it at 2200 miles. Glad to see it's somewhat common. Mine is the Limited with 18" Michelins and agree it's not related to the tires as the rpms & throttle position matter need to be as described above to make it occur.
 
#21 ·
I have it too. I thought it was the full time 4 x 4 hunting uphill or something... Never thought it was the engine.
 
#23 ·
Really starting to think its just the way it is with everyone chiming in they have it. And I wonder if the ones that dont just don't notice it. It really doesn't bother me as log as it is not something that can cause damage...
 
#24 ·
i have a similar noise,if you think it is the tire try putting on the spare it should be a 18" kumo.i'm going on over 1 month in for the same repair it was not there when we bought it but started slowly until now you can here it over the radio at times.it is almost like wetting your finger and running it around the rim of a whine glass a roational sound.we are trying a large dealer who sells several other imports like audi and mercedes.
 
#25 ·
I have posted the following and was referring to your post which seems to be quite the same what Im experiencing.
i have a strange hum sound (sine wave sound)
coming from the motor when slowly acceleration over 60 mph. about 1 cycle in 1 second.
it dissapears after releasing the gas pedal.
on GC 2011 Laredo X 70 anni. 3.6L. ~10K miles.

Is this what you described ? Did you find out the reason and solved it ?
 
#26 ·
I am experiencing almost the exact same thing here. At around 2000 or so RPM and 60 mph while going uphill I get a pulsing sound/vibration from the front left ish side of the car. Anyone have any update here as to possible causes and solutions? I have a new 12 limited w/ 18'' wheels. Thanks.
 
#27 · (Edited)
Just bought my Jeep Grand Cherokee a month ago and have the same issue. Noticed it a few days after I bought it. I called the service dept and they seem to be aware of the issue but had no solutions. Can make it happen when going up small upgrade while accelerating to around 2100 rpm at 60 mph. Is also a pulsating type sound. Have contacted Chrysler at the link provided from one of the other posts. Definately not a tire issue. After paying 40k for a vehicle not satisfied with it being a "normal" symptom of the engine/transmission. Have a new 2012 limited with 18'' wheels
 
#28 ·
Mine has a high pitched, very slight whine at exactly 61 mph. You have to turn the radio and AC off to hear it.


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