93 Pathfinder: Yet another auto trans issue

Apr 30th, 2003, 12:40 PM

Hello,

93 Pathfinder, 135K miles. The car has been exhibiting a problem with the auto trans for about 3 months now. When the car has been sitting for a few days or if it is a little colder out than normal (say 45-50 degrees) the trans malfunctions in this manner:

If I go up a hill the car will not downshift but will either chug up the hill in a higher gear or will outright stall. If I go down a hill, the car will not disengage from gear as I coast to a stop and will chugga-chugga and then stall. After these initial occurences, the trans works great - crisp shifts, no lag, everything is fine. If the car is warm there are no trans probs.

Another symptom, which has only happened a couple times, is that once I was parked on a hill and every time I put it in R, the car would stall. Another time, I was parked on a level surface and I would put the car in D and, again it would stall. Both times it was fairly cold out.

I should note, this car has been babied and maintained its whole life and has never towed anything.

So far I have tried a fluid change (three times actually -- the first time with Dexron 3 and then again with Nissan Madic ATF or whatever the heck it was called and then Dexron 3 again) and have tried some Trans-X additive. I tried to do the filter but the dadburn exhaust is in the way and so I put it back together with yet another fresh fluid change.

I am thinking of taking it into the Nissan dealer for a flush/fill/filter change as a last ditch resort before I start thinking about putting in a reman trans. Any ideas here?

Thanks for any helpful replies.

Mark

2000SE · Apr 30th, 2003, 03:36 PM

Replace the filter(if equipped) and have the transcooler cleaned.

Also, it is time to check any applicable transmission and engine adjustments if available. This includes VB(vacuum or mechanical) linkages, solenoid function, transmission line pressures, engine TPS, vehicle speed sensors........
If you don't have an FSM, it might be dealer/trans shop time.

If the tranny if fully electronic, then there could be an electrical short(ground or harness), failed solenoid(s), or TCU/ECU issues.
This might be better off looked at by the dealer. Most tranny shops want the rebuild profit and don't care about simple fixes.

What kind of maintenance did the tranny have over the 135k miles?

I would also get the transx out of the transmission. Additives have never rebuilt a transmission.

Are you using a drainplug or dropping the pan for the drain/refills?

aaronford · Apr 30th, 2003, 09:06 PM

Hey, I agree w/2000se. You stated that the fluid had been changed three times, but sort of alluded to the idea that you had yet to change the filter. An auto tranny uses wet clutches and the dislodged friction material goes in the oil. This material usually ends up in the filter and will eventually clog it causing it to be highly restrictive to thicker (cold) oils. If the clutches aren't slipping (loss of power, excessive revs) the tranny probably does not need rebuilt. If this isn't it, perhaps you are looking at a torque converter lockup problem, likely electrical in nature. I have seen trans-x fix a seal, but only temporarily. It did get us home, though. Good Luck, Aaron Ford