7 Speed Auto Transmission - Coasting Status?? - MyG37

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7 Speed Auto Transmission - Coasting Status??

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7 Speed Auto Transmission - Coasting Status??

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Old 06-12-2018, 09:29 PM
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Spadds76
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7 Speed Auto Transmission - Coasting Status??

Hi

When I take my foot off the gas when cruising at say 40 mph, the car in 6th or 7th gear, my revs drop to idle, drive seems to disengage and the car will coast along like this until I put my foot back on the gas, or brake. when i do either it will pick up where it left off, engaging drive at the required rpm to speed forward or shift down to slow down for stopping.

I don't recall it doing the above at all before. I think the rpm were continuously engaged when I took my foot off the gas - just like a manual transmission. I liked this about the car as the ride is smoother. My old Volvo xc90 used to disengage the drive and revs drop to idle when coasting, and when accelerating it seemed like the box and engine were never working with each other but inefficiently working against each other.

Does anyone elses G37x do this? Mine is MY2010.

Is this anything to be worried about - is it early signs of wear in the box - car has 240,000 km on it.

It drives and accelerates like its taking off to the moon!!!

cheers

Spadds
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Old 06-13-2018, 07:11 AM
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RMB5190
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Mine does this...something, something...fuel efficiency. If it's in 'D' the car is going to want to get into the highest gear possible to maximize MPG. Very normal to my understanding. If it's not for you, perhaps 'DS' mode is what you want to be in.
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Old 06-13-2018, 02:45 PM
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slartibartfast
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I don't think that's what he's talking about. He's asking why the trans feels like it disengages when coasting down. I get this every now-and-again but it happens when coasting as the A/C compressor kicks off.
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Old 06-13-2018, 03:10 PM
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RMB5190
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If that's the case, can't say I've had it happen. I've had my car try to get into 7th at 40mph and the moment you need to speed up it does its stumble into a gear thing. Not sure about the disengaging aspect.
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Old 06-13-2018, 05:19 PM
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OP does this happen in D only?

What about S or manual mode? Have you tried testing?
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Old 06-22-2018, 06:41 PM
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Spadds76
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Originally Posted by kroy View Post
OP does this happen in D only?

What about S or manual mode? Have you tried testing?
Hi - it only happens in D. not S.

In S it drives like it used to do in D - RPM/engine always engaged together. when i take my foot off the gas, the car starts to slow, as do rpm and car together.

I put it back in D and when at speed I take my foot off the gas, the rpm drop to idle speed and the car coasts until I press the throttle where it then engages drive/ with the wheels.

I wonder if this has anything to do with my 150k miles atf change.....
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Old 06-22-2018, 08:24 PM
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What you're experiencing is normal operation. It's the torque converter locking up and unlocking.
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Old 06-22-2018, 09:21 PM
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Originally Posted by qmantran View Post
What you're experiencing is normal operation. It's the torque converter locking up and unlocking.
Thanks very much for the confirmation of operation!!!!
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