Tranny Problems, 91 Pathfinder

[sanford7575]

I need serious help.

I am the new owner of a used 91' Pathfinder SE 4WD (Automatic) with what I think is a slight transmission problem.

My Pathy drives fine except that when shifting from 1st to 2nd and from 2nd to 3rd, it shifts very hard and it seems like the shift point is too high. For instance when shifting from 1st to second, the shift seems to occur at like 3500 RPMs.

The shift point is also 3500 RPMs when shifting from 2nd to 3rd. This doesn't sound natural as the engine seems like it is revving too high. Also, shifting from 3rd to 4th is more smooth as the RPM's are only around 2700 RPM's.

I've already added Lucas Oil trans fix, and the fluid level is fine.

 

My Pathy has 94,000 miles on it, do these tranny's start to have problems this early? Will a tranny flush cure this?

 

I heard that there is often a failure with the Transmission oil cooler, can I check this or is this something the dealer has to do? If it is the tranny oil cooler, how much can I expect to pay for a repair?

 

I heard that there was some kind of diagnostic code to diagnose tranny problems, has someone posted this? If not, can someone send me the procedure?

 

Oh yeah, one more thing that I noticed is that sometimes the colored dash light that illuminates what gear you are in (P, R, N, D, 2, 1) often blinks and flashes on and off when I'm in drive. Sometimes it stays off for a short period of time.

The light never seems to do this in any other gear.

 

Any and all help is greatly appreciated.

 

Thanks

[Mr. Pickles]

I need serious help.

I am the new owner of a used 91' Pathfinder SE 4WD (Automatic) with what I think is a slight transmission problem.

My Pathy drives fine except that when shifting from 1st to 2nd and from 2nd to 3rd, it shifts very hard and it seems like the shift point is too high. For instance when shifting from 1st to second, the shift seems to occur at like 3500 RPMs.

The shift point is also 3500 RPMs when shifting from 2nd to 3rd. This doesn't sound natural as the engine seems like it is revving too high. Also, shifting from 3rd to 4th is more smooth as the RPM's are only around 2700 RPM's.

I've already added Lucas Oil trans fix, and the fluid level is fine.

 

My Pathy has 94,000 miles on it, do these tranny's start to have problems this early? Will a tranny flush cure this?

 

I heard that there is often a failure with the Transmission oil cooler, can I check this or is this something the dealer has to do? If it is the tranny oil cooler, how much can I expect to pay for a repair?

 

I heard that there was some kind of diagnostic code to diagnose tranny problems, has someone posted this? If not, can someone send me the procedure?

 

Oh yeah, one more thing that I noticed is that sometimes the colored dash light that illuminates what gear you are in (P, R, N, D, 2, 1) often blinks and flashes on and off when I'm in drive. Sometimes it stays off for a short period of time.

The light never seems to do this in any other gear.

 

Any and all help is greatly appreciated.

 

Thanks

Um, I don't have an auto, so I could be up a tree, but 3500 seems perfectly fine to be shifting at, especially if your putting any gas to it.

[denisb]

You could be having a cooling problem, this would cause hard shifts. I think the hard shift is a fairly common problem. Mine has a hard shift when cold from 2nd to drive. It should probably brought to a trany shop for a test drive to confirm.

 

As far as your blinking light, I'm thinking it's probably the tranny going into power mode, especially if it does it when stepping on the gas. My 90 has a power A/T button with a light that comes on when it goes into power mode. Hope this helps ease your mind a little.

 

Denis

[88pathoffroad]

These Nissan autos shift funny to begin with, so I wouldn't necessarily worry about what RPM it shifts at unless it's causing problems or obviously shifting too high or low. It's entirely possible for the auto tranny to have problems at your current mileage if it was abused in the past, neglected or overheated.

 

A flashing Power dash light means that there is something wrong with your transmission. Go read the pinned post in the Garage on how to run diagnostics on your auto tranny if you want to go that route.

 

The tranny cooler is inside the stock radiator. It should be completely bypassed and you should get an aftermarket cooler instead. An aftermarket cooler costs about $60-$125, depending on what kit you get. Install is extra if you can't do it yourself, of course. It's not hard to add one, though.

[NissanPerson]

First of all, since you're a new Pathy owner I'd suggest checking to make sure the switch isn't in power mode or whatever it is. Also, Pathfinders in the 88-95 years aren't exactly known for acceleration, so if you're used to being able to take off fast you may just be giving it enough gas to make it shift at those RPM's. I normally shift around 3000 RPM's when I'm driving in town and about 3500-4000 when I'm entering the freeway and what not. So, it's not uncommon if you're a lead foot or you like to punch it down. Anyway, maybe get it checked out if it's really bothering you or if you're having other problems as well.

[lgranch]

Are you still having trouble?? It is a little over 2 weeks since you first posted. I be glad to help you run the diagnosis on the tranny if you still need to. :secret:

[sanford7575]

I'm still having sporadic trouble shifting, but I have learned to time the shift of the Tranny and I now ease the shift by temporarily taking my foot off of the accelerator.

 

I ran the diagnostic on the tranny, and I got nothing but 10 equally flashing lights.

I believe that this means that there is nothing wrong.

 

I have an appointment with the dealer on Saturday for a complete fulsh and fill and I have purchased a Perma Cool Filter and Tranny Cooler that I will install inline with the stock cooler in the radiator after it's flushed.

I may also have the dealer do a tranny diagnostic just to make sure as well.

 

I believe that some may have misunderstood which lights are blinking on my dash.

The orange light on the power mode button on the dash is fine. It is not blinking abnormally. However, the green light in the middle of the dash that indicates that the truck is in drive always flashes and then goes off after like 15 minutes of driving.

 

One more thing I did want to ask is how are people bypassing the stock tranny cooler? I've been told by many people that bypassing the stock cooler will only cause problems because aftermarket coolers will cool efficiently when the car is moving and air is coming through, but that they will not cool effectively in traffic when the car is standing still idling. I was told that you need the stock cooler and the radiator to aid in the cooling process.

[lgranch]

First off with the light in the dash flashing you still have a problem somewhere. I'll look that one up and get back to you.

 

As for the tranny cooler, An aftermarket cooler is just fine in traffic. There is only one potential issue with the aftermarket cooler. In really cold weather the engine will bring the tranny fluid up to temperature faster with the stock cooler. I think that is someone's idea of an advantage. It may have been very true in the old days, but now the tranny fluid is so good that I doubt it maters much. Go with the after market cooler.

[gacruiser]

The dash light is indicative of a bad indicator switch. Mine has been intermittant in the past, but clears up when I wiggle the shift lever back and forth. I figure the switch contacts have gotten corroded or worn, although I haven't had any problems in the last year or so.

 

As one poster mentioned (above), it sounds like you have your dash switch set in the "power" mode, rather than in "auto". That will cause hard shifts and the exact symptoms you mention.

[94extreme]

I'd bypass the stock cooler if I were you. I don't think a flush is really gonna clear that thing, and you don't want to start with a new cooler full of crap.