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Discussion Starter #1
when I (always) drive between 70 to 100 km the vehicle upshifts and rpm drops to nearly 1000 and the engine starts roaring naturally. it is quite annoying. Is it normal? Do u have the same problem while driving at low speeds? When I shift manually and keep the rpm above 2000 I don't get that roaring sound. Mine is a 2012 lt.
 

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It is called engine lugging and or low speed resonance. In order to squeeze as much efficiency out of an engine to comply with CAFE standards doubling in 10 years, they have the transmission to shift up sooner to reduce engine rpm and save fuel. I have a 2012, and running 87 octane, it will cause the knock sensors to trigger and ignition timing to plummet. Engine noise increases and power decreases. I switched to 93 octane and all the knock disappeared, sound was much lower and more power and slightly more fuel efficiency. I would hear the same noise on the highway, on cruise, in 6th gear going up small to moderate hills using 87 octane.
 

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Discussion Starter #3
I always use 95 octane since i bought Traverse but the sound is too high especially in-city speeds. I really hate hearing that noise and whoever with me in the car quickly tells me whats wrong with the car. But it really seems that it is something about fuel efficiency since it is working at very low rpm. Thank you for your reply at least knowing that it is something normal would annoy me less:)
 

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I always use 95 octane since i bought Traverse but the sound is too high especially in-city speeds. I really hate hearing that noise and whoever with me in the car quickly tells me whats wrong with the car. But it really seems that it is something about fuel efficiency since it is working at very low rpm. Thank you for your reply at least knowing that it is something normal would annoy me less:)
If it is excessively loud, I would get it checked out. May not be normal. When I drive in the city, I manually set the transmission to 3rd for speeds up to 35, and 4th gear up to speeds of 35-45. The constant shifting through all those gears repeatedly is hard on the transmission and clutches at low rpm and higher loads, I believe will shorten the life.

If you have not done so I would take it to the dealer and get a full fluid exchange on the transmission. I do this because the filter is not replaceable and no pan to clean.
 

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hmmmm, roaring..... nope.
My 2010 is quiet.
audio/video would be nice.
 

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I always use 95 octane since i bought Traverse but the sound is too high especially in-city speeds. I really hate hearing that noise and whoever with me in the car quickly tells me whats wrong with the car. But it really seems that it is something about fuel efficiency since it is working at very low rpm. Thank you for your reply at least knowing that it is something normal would annoy me less:)
I checked today, in Drive, the engine and transmission is keeping the RPMs between 1500 and 1800 in city driving conditions. If it getting that low, I would more closely at the transmission. May need to go to the dealer and have they do a re-learn on the transmission shift patterns. I have seen this resolve minor driveability problems.
 

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Discussion Starter #7
if I drive continuously at lets say 80 for 5 minutes. Rpm drops to nearly 1000 and when I let on gas pedal it roars and never stops. I dunno but as u said there may be something wrong about shifting programming.
 

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if I drive continuously at lets say 80 for 5 minutes. Rpm drops to nearly 1000 and when I let on gas pedal it roars and never stops. I dunno but as u said there may be something wrong about shifting programming.
They way you describe it, and at that speed and time, sounds like your torque converter or transmission shudder. When you apply throttle it should release, and down shift if enough throttle is applied. Does it shift down automatically under load. In most cases a fluid exchange will help with this problem. Fluid breaks down and may cause this problem.

From ItStillRuns,

Diagnosis

Transmissions can shudder in a very similar manner to torque converters. To determine whether the shudder is tranny or TC related, run your vehicle for a little while till it begin to shudder and immediately park it. With your foot on the brake, put the transmission in Drive, and apply light throttle. If you feel shuddering, then it's the Torque converter; if not, then the problem is within the transmission.

Solving the Problem

Unless there is physical damage to the converter or transmission, shudder is a fairly easy problem to solve. Once the transmission fluid has been overheated enough times, it becomes permanently de-polymerized and need to be replaced. You can do this yourself by draining the transmission and flushing it, or taking it to any competent mechanic for maintenance.
 

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Discussion Starter #9
I have recently had my transmission fluid drained and refilled once and after 3000 kms I had it done again but nothing has changed. Thanks for your interest and help.
 
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