tszymans

I've tried reading through some of the various posts on this same subject but i couldn't seem to find consistent response other than "Let it warm up"; which yes will work but there is something else that is causing this problem and I want to know what it will take to fix it since I'm going to be selling the car soon and would like to pass it off in a decent condition. But anyways...the problem.

The Max is a 1997 GXE Auto w/ 141,000 miles, no MODs.

When it is cold out side (>35F) and the car is parked out in the cold, when I first start the car it will start up just fine and have ~1200 RPMs until it begins to warm up and will gradually drop to ~800. However if I attempt to shift into any gear before the car is warm it will stall (unless I tap the gas to save it). However if I am able to successfully shift into a gear without a stall (because it warmed up just enough or it wasn't too cold outside), once I start driving the shifting is slightly erratic almost like it can't decide which gear it wants to be in. And if I come to a stop the RPMs will drop very low to almost 200 like it's about to stall and then bounce back up to 800 and runs fine. I have not had it stall while driving only upon the initial shift into gear. I also want to be clear that the transmission is NOT slipping, I am able to accelerate from a stop or a roll completely normal and the shifts are not abnormally hard. But in the end once the car has warmed up everything runs just fine. And I realize that most people are going to say to just let the car warm up, but this isn't normal and didn't start to happen until just recently; I'm trying to figure out the root cause.

Is the tranny possibly starting to go out? I know I've read mixed things about doing a fluid flush since it does have quite a few miles on it. I know I've never changed the fluid and I've had the car since ~85K. Would a fluid drain and fill help at all?

OR I'm open to other possible causes.

njmaxseltd

iTrader: (19)

Check the engine coolant temp sensor.
Clean the throttle body and the IACV (do this first usually solves most idle control issues)

JtzMax

iTrader: (5)

Excelent place to start!

Have you cleaned the TB or IACV? Doing that will likely solve your problem. You should also check the air filter (if it can't breath, it won't run) and maybe clean the MAF. If you do all that, it'll be like you're driving a different car.

cooler2000

I have same problem! It developed like 2-3 years ago. It appears only when it is very very cold outside, so I have to warm up car till it is very warm and i can drive without problems.

So what is part number for engine coolant temp sensor? Where in our Maxima it is located? I would like to do it asap by myself or go to mechanic.

Thanks!!!!!

TunerMaxima3000

iTrader: (4)

Good 1st suggestions.

I was thinking it sounds like the torque converter.

Dave Holmes

The engine coolant temp sensor is available at Advance Auto for about $21. Made by BWD, part #WT3071. You can check it on their website or AutoZones. Very simple to replace. Follow upper radiator hose to where it connects to engine. In the metal coolant pipe, you'll see two sensors. The front one (with one wire) is our gauge's coolant temp sensor. The second one (with two wires) is the ECU's engine coolant temp sensor (and the one you want to replace). The Haynes manual says to drain coolant first, then unplug sensor, unscrew it, and reverse for installation. I did mine last week while doing my cooling system maintenance.
There is a test with an ohmmeter you can use to test yours. I can't remember the exact specs (they're in the FSM, and possibly Haynes), but I remember mine was out of spec. I was having a cold idle issue (different from yours, my idle was too high), which is why I checked/changed mine. It didn't fix my high cold idle. But it is definitely worth checking on yours. If it fails, replace it, and go from there.

Dave

ImmaSquashYou

iTrader: (7)

mine was exactly likes yours....it had to be warm..otherwise it would stall...i switched out mafs...cleaned out tb..changed vehicle speed sensor..changed most of the sensors and such...wound up needing a new tranny...i would not change out the transmission oil out right now...i know it kinda sucks..but sell the car for a little less....and get it out of your hands if you were planning to get rid of it anyways. You can be honest if you want, but just tell them that it will stall if it doesn't warm up and let them deal with it and you don't know whats wrong (in case you really don't). Just don't look into it any further...

the reason why i changed out all the parts was because my mechanic said that it was my transmission..but i didn't beleive him since everything was fine and only acted up when it was not warmed up....it wasn't cold outside since it was the summer...but if it wasn't warmed up...it was really bad...i changed out the tranny oil and it got worse..so i wouldn't do that if i were you...

JtzMax

iTrader: (5)

TC will give you problems hot or cold. I can't agree with the above post - sell the car for a $21 part / problem. That's giving up and you don't get ahead if you give up.

This problem is not overly comon but shouldn't be that difficult to fix. You don't just start 'shotgunning' parts at the car either. There are ways to test things / sensors. Once you take the time to test things, you'll find the problem and it should be fixed.

TunerMaxima3000

iTrader: (4)

Well put. Giving up wont benefit you in any way, unless you just want to get rid of the car and don't care what you get for it.
A car in working order is worth way more.

After reading your OP over a couple times, I am thinking much less likely that it's the torque converter. Usually when they slip the RPM doesn't fluctuate

talisman311

Well damnit... my car's starting to do the same thing and I change my fluid regularly. I'm at 160k now, and it just feels like the torque convertor won't disengage when I stop, but will shift fine. Temp is under 25 degrees outside. Input guys?

pmohr

iTrader: (26)

So the idle dips down when you come to a stop? No idling issues otherwise, or hot/cold start issues?

No CEL?

tszymans

Sorry for the delayed response but I wanted to give the engine a few genuine "cold starts" before I came to any conclusions. But I took the advice of the first post on cleaning the TB and IACV (I also cleaned the MAF while I was at it and changed the plugs, they've been due for a while and I had them just sitting on my tool box). But yes, the TB and IACV gave new meaning to the term "Gunked Up". So I gave em a good hose down and scrub down with a toothbrush using plenty of TB cleaner. But now she starts a ton easier with only a crank or two jumps right up to ~1500 and when put into gear only drops to around ~1000. After it's had a chance to warm up a slight bit the RPMs when I initially come to stop drop to ~850 and then slowly drop to ~750 and hold steady. All the shifts and everything seem much smoother and more responsive now too (I'm sure the new plugs didn't hurt). Thanks for the help guys.

(I'll post pics once I get them uploaded to a web-page)

As far as the thermostat goes, I really didn't think that was it because the car warms up just fine and I can blow plenty of hot air out of the heater so it's not just constantly pouring coolant through the system (or not pouring at all for that matter either).

And just for the curious I was never throwing any codes to the CES light (Other than my lovely O2 sensor code).

JtzMax

iTrader: (5)

Glad you got it 'better'. Didn't know you had the plugs just layin around - good call. As for the gunked up TB / IACV that typically will not throw a CEL, but as you see, it will make your car run like crap. How's the air filter look?

Maximus681

i cleaned the iacv and tb and still does the same thing... i found low tranny fluid, could that cause it?

pmohr

iTrader: (26)

Not likely, but why not top it off and see for yourself?

talisman311

Yeah, the best way I can describe is it's like driving a manual and then not releasing the clutch when you come to a stop. And if I shift it into gear, it's like dropping the clutch without any gas and stalling the engine. Not sure how it could be related to the TB or IACV as it starts fine, idles fine, and runs fine.

pmohr

iTrader: (26)

The last auto in my car did the same exact thing. Took apart the torque converter, and that was the problem.

That was my excuse for a 5 speed swap.

talisman311

Yeah didn't think it'd be an easy fix.. I think I'll just deal with it for now since it'll get warmer soon enough. It's still shifting fine so I hope it'll hold together for the next 6 months as I'm about to be transfered from Richmond, VA to Nashville, TN for my job.

JtzMax

iTrader: (5)

Before you go spending too much $$$ ... try just having a trans service (flush and fill) done on it. Shouldn't be too much $ and it might save you from a lot of headaches and frusturation.