My friend's 3rd gen auto w/ 87k is doing some strange thing. If its engaged in either reverse or any of the drive gears, it will start vibrating - almost seems as if its missing a cylinder. I doubt its ignition related since it would be acting up while in park or neautral.

I drove the car and it drives and shifts fine minus the vibrations its causing. I am guessing its transmission related and maybe a torque converter gone bad???

 

look for a miss anyway.
it's easy enough to check.
also check your motor mounts

 

fuel injectors or maf sensor maybe?

 

my girlfriends 2000 altims SE does that... it has 175k miles on it...... it feels like the idle gets too low in gear.......

 

Low tranny fluid?

 

You might have to change your spark plugs or wires check them.

 

s he does have VERY low fluid, but the fluid has never been changed........ it is almost black... im thinking of adding lucas... but im not sure if the lucas will even mes it up with 175k on the original fluid..

 

Ouch. Sounds like it's burned up. Could be due to low fluid. Might try to replace fluid and install some Lucas. Might get some more time out of the tranny.

 

You sure about replacing fluid?...wouldn't that just = replace tranny sooner than necessary? could probably run on that black original fluid a few miles more before it fully dies, Rather than killing it faster with new fluid.

 

if it's vibrating on reverse or drive it's likely that your car is going to hesitate even more when you accelerate. i suggest that your fuel system is messy, but most likely your fuel injectors. your best bet is to buy fuel additives like a bottle of STP fuel system cleaner and put it in your gas tank the next time you refill gas. then after at least 1 or 2 days it should be fine.

 

thats what im afraid of..... i am NOT gonna put new stuff in...... but i was debating on adding a bottle of lucas... but that even might mess it up....

 

if your trans is just starting to slip, then change the fluid you won't make it any worse.
I improved my old sable's tranny by adding a couple bottles of lucas to it. still slipped, but at least it didn't bang anymore