Hey guys,

From all the posts on transmission problems I've read in this forum, and there are a lot of them, I have been unable to find anyone with a problem similiar to mine. They mostly speak of transmissions making noises, grinding, slipping, taking too long to get into gear etc... I don't have those problems, but something is definately wrong.

Here goes... this is all on a 1992 GXE Maxima w/ 128,000 miles.

Basically, my car is pushing too many RPMs for the speed I am running at. At 50-60 mph I push 2100-2300 RPM. At 70 mph it runs anywhere from 2200-2500 RPM.

If I have been driving for 25+ minutes on the highway (I-5 in my case) I can usually get it to drop to 1950 RPM or so for 65 mph, or at least hover around 2000 RPM. The overdrive is engaged, I can see on the tach when it disengages so I am positive it is working. The tranny doesn't randomly change gears, so it picks one it likes and sticks with it.

In other gears, it also seems excessive... 25 mph @ 2000 RPM doesn't seem right or healthy. Especially when not climbing.

The tranny shifts fine, no jerky shifts, no sudden RPM climb when it shifts, no lag when shifting into reverse or drive.

When I give it gas, it sometimes seems like there is an RPM lag, meaning it needs to gain RPM before I get the full impact of gas. My car moves immediately when I hit the gas, but the tach needs to climb sometimes to get to a point where the RPM then increases with speed. This seems to decrease substantially, but not go away completely after 20-25 minutes of driving.

When I first bought the car, 8 months ago, it didn't do this.

As far as I can tell my transmission fluid is not low. I get different readings every time I check it, but they all are either at the bare minimum, or somewhere in the middle. I always check it hot, my manual has guidlines for checking it cold, which I still have to do (waiting for my car to cool now). The fluid is still a nice bright red.

My gas mileage has also gone to hell. I used to push close to 400 miles per tank, and I am lucky if I get to 250 now. Usually I don't get that high. My mileage is also horrible when the car is cold, every now and then I do long highway trips (200 + miles) and from simple experience, if I do 1 hr plus trips my mileage is much better, approaching normal almost. 25 minute highway trips don't make my mileage better, it has to be long 1 hr plus trips. As it stands now my driving is split basically 1/2 highway, 1/2 city (Seattle) driving.

Sorry for long posts guys, but maxima.org has already been very helpful with other stuff (crappy bose amplifiers) so I thought you guys might be able to help here, as I am basically car illiterate outside of changing oil and pumping gas.

Any ideas? I'm so poor right now that unless a fix is uber cheap, I am going to have to wait until I get my degree to fix it. Unfortunately, the prospect of a 2000 dollar tranny rebuild is frightening.

Thank you!!!

 

To fix my transmission "turbo" lag problem I simply gave it a full tune up. New Plugs, ignition wires, air filter, oil change, transmission fluid flush, cleaned MAF sensor, cleaned throttle body, cleaned battery terminals, cleaned various electrical contacts (TPS, Idle Switch, MAF, Fuel injectors..etc) I also tested a number of various sensors and other things, made sure they were within factory specs. How does it run after all that? Like a brand new car.

Most of the stuff I listed is cheap or free to do. I think your problem is your transmission fluid. When you check it, warm the car up to operating temp, switch between ALL the gears (P,R,N,D,D2,D1) up and down, leave it in park, then check the fluid level. You could also check if the transmission control unit has any stored error codes, I know someone listed the procedure before.

good luck

 

I think you're car is all right. What happens it seems with esp our older maxima's is that the ATF needs to be fully warmed up for the torque converter to lock up.

You see, the tranny has 4 gears, and when you're above 43-45mph the torque converter(t/c) will "lock up" to make the tranny more effiecent. SO, next time test this: Get on the highway while you think your car is reving higher than normal. Then say as you're holding 65mph, give it some gas, take your foot off, give it some gas...etc...etc...BUT NOT SO HARD that it downshifts to 3rd. You should see the tach flucate a couple hundred rpms or so b/c the t/c has not locked. Now, once the t/c finally does lock up in your car, do it again(but don't take your foot all the way off the gas-that will unlock the t/c on the highway). You'll see that as you give more gas the car will accerate a bit, but the tach will barely move.

It could be that its just cold, or maybe the ATF temp sensor is bad? But...you're tranny sounds fine.

Go do this test and report back to me.

Mike S.

 

Hey guys, thank you both for responding here.

Okay, so I took a nice 100 mile trip in the car and did the things you asked for.

The torque converter is locking up, when I give it gas I will get no RPM increase unless I really give it gas. But then if it isn't locked it will move around, so that works... cool!!

I took some RPM vs mph measurements, and I push exactly 2500 RPM at 80 mph, and 1650 RPM at 50 mph. With overdrive engaged. Does that sound right to you guys? Unfortunately the only car I ever drove with regularity was my old 1985 manual tranny Nissan Stanza, so I have absolutely nothing to compare my current car to. It just seemed excessive to me based on the few times I drove my parents 1993 3.0 Mercury Sable... probably not a good car to compare the maxima to.

I changed the oil today and cleaned off the battery terminals, and I think I can change the plugs myself, that doesn't seem to difficult, and I'll get the tranny flushed when I get some cash. I also think I found the procedure, or A procedure for checking that, so I'll do that too.

Maybe I jumped to conclusions and automatically attributed my crappy gas mileage problems to a bad transmission. Is there anything else I should check out that might be adversely affecting my mileage? I'll run one of those fuel injector cleaner thingys through my tank next time I fill up, and I know my tires all have the correct pressure...

So Mike and Sudesh, thank you guys for taking the time to help me out here!!

 

Those tach numbers sound dead on to what I get. Usually 65mph at 2000 rpm and 75/80 is around 2500 rpm. I think your tranny is fine.

 

Agreed. Your tranny is fine. Your simply just locking up untill the ATF is fully warm, and hence the difference in rpm speeds. Glad to see all is ok.