Question on transmission issues

[steve c]

Not sure what forum this belongs on, but with my daughters car, when she stops at a light with car in drive, it feels like the thransmission is 'dragging' or something. With foot on brake, the rpms drop lower then say with car in park and there is a vibration, sort of like the engine wants to stall. Not sure how long it's been doing thos but it definitely didnt do it when new.

Anyone have insight on this?

 

[racer12306]

What car?

 

[steve c]

2010 Nissan Z, 7 speed automatic

 

[thastinger]

Torque converter may be staying locked up, you would need a scan tool of some sort to see if the ECU was commanding the transmission TC to remain locked, if it is commanding an unlock then it would be either a bad soleniod or a bad TC. When was the transmission last serviced? The 7 speeds are usually pretty robust, especially in a liteweight vehicle like a 370

 

[steve c]

Not sure on service, possibly never. Would a fluid exchange help with this?

 

[steve c]

Just broke 120k miles

 

[JavierH19]

Could be, it's a mercedes 7 speed so maxlife would work. At 120k it's well overdue but there could be something else causing it.

 

[WeyounDS9]

Not sure on service, possibly never. Would a fluid exchange help with this?

Possibly never in 120,000 miles???
Yes. uhm, it needs new fluid.
Probably all gummed up in the inside and fluid additives used up.

 

[steve c]

Lightly driven. The manual doesn't recommend any service interval for transmission fluid for non severe service. LOL

 

[Sequoiasoon]

Lightly driven. The manual doesn't recommend any service interval for transmission fluid for non severe service. LOL

Always go with severe service. If you read what they define as that you will know.

 

[CleanSump]

The 7G is a transmission Mercedes put in many cars including my E320. MB says lifetime fluid, but the maintenance manual showed a 60k mile initial fluid/filter change for my 2008.
I do a spill and fill every 40k.

 

[steve c]

Problem solved. Engine air filter was very dirty. Engine struggled to stay alive at idle rpms due to constricted air flow. Not a transmission issue thank God. Replaced air filter, now it's good.

 

[ElectroMechanoMan]

It would be a good idea to change the transmission fluid anyway. That’s just good maintenance.

 

[ripcord]

Sounds like the vehicle has been neglected.

 

[Drifter]

Y'all dodged a expensive bullet. Nice

 

[zzyzzx]

Problem solved. Engine air filter was very dirty. Engine struggled to stay alive at idle rpms due to constricted air flow. Not a transmission issue thank God. Replaced air filter, now it's good.

Reminds me of a recent YouTube video by YouTuber Just Call Me Eddie where someone brought in a Subaru that the customer said wouldn't get out of 1st gear (must have been made before Subaru started using CVT's). It turned out to be a clogged exhaust (blocked converter). He claimed that it needed a new catalytic converter, but didn't elaborate in the video as to if there was anything else potentially causing the catalytic converter to go bad.