My 5A/T jerky problem is a lot better after I correct the trans fluid level, but 2-3 shift (in auto mode) still jerky when it is getting hot (after 10 minutes traffic jam on highway).
Does anybody have the same prblem?
Does G have a A/T cooler? If not, should I install one? Where can I get one? Will the dealer help to install?
Or should I flush the coolant?

Thanks.

 

No it doesnt have an external cooler. Only cooled through the radiator. Sounds like you might have a bit of a tranny problem.

 

The AT can be jerky in manual mode. The shift from 2-3 is really rough sometimes. If you're talk auto mode, then I'd get it looked at.

 

It is in auto mode. The dealer couldn't duplicate the problem because the car has to be very hot to have that. The car is still under the warranty.

 

Duplicate the driving experience that gets it hot and drop by the dealer to get the shop foreman to drive with you to experience the same thing.

Under normal driving you shouldn't have to worry about an external trans cooler. If you track the car, drive regularly in hot conditions with stop and go traffic or tow a trailer you should consider one.

The coolant should be flushed after 2-3 years.

G/L

EDIT: I just checked with my local dealer (was going to get mine done) and the coolant on all G35s is to replaced at 5 year/80K kms

 

Thanks. I drive on the highway for 40kms to work and sometimes it is stop and go traffic and that is when I feel the jerk between 2-3 shift. So where can I get the cooler and where should I go for the installation?
Mine is 2003 (I bought used one) and I think the coolant was never flushed. Do you think that could be the problem?

 

This might help you out:

http://www.autoanything.com/coolers/65A3046A0A0.aspx

 

First off let me qualify by saying I don't have a G with AT.

I would let the dealer help diagnose the tranny jerk problem. My personal opinion is if your fluid has been changed and you still experience a jerk between shifts (beyond what is normal in these cars) there is something wrong in the transmission. IMHO, changing the coolant won't help this. However it is preventative maintenance to ensure your engine and transmission operate at proper temperatures and should be done if it hasn't already. The cooler will help ensure a proper transmission temperature under what would be considered heavy loads. That said I wouldn't go spending money on coolers until the problem is identified.

Perhaps some AT owners can chime in with their experience.

 

The jerk is not like the whole car shaking, it is like losing power for .5 second and bang into gear.

 

Is it consistant?

It's easy to induce a bad shift in auto mode;
if moderately accelerating & just before the shift point you easy off the throttle = a rough shift.

Basically you can fool the shift logic.

 

It is not consistant. Only when the car gets very hot in stop and go traffic.

If I slowly accelerate & decelerate, no problem. If I hold the gas or let off the gas quickly before the shift point, I feel the rough shift between 2-3.

I don't mind the rought shift too much, just don't want to spend $7000 to replace the tranny after warranty expired. Car is 90k, still 20k to go.

Thanks!

 

^ yes, the type of thing that happens more in stop and go highway traffic.

 

Yes ^WHS... that's normal.

You can help by either anticpating traffic flow to regulate the throttle better.
OR
I used MMode a lot in stop & go to hold the gear and keep it from shifting.

 

That is definitely good advice. I will try to use manumatic next time.

 

How do I make sure the auto trans will not break after warranty expired? The dealer told me if there is no warning light on the dashboard, they will not be able to find anything by doing road test. Any advice will be appreciated.