99 sportage auto tranny slips when cold

[kiauser]

my 99 sportage 3 speed auto tranny slips when its cold, fluid is fine when i bought 3 yrs ago no problems. started last winter, after about 1 mile it will finally shift to third if the outside air temp stays above 75 its usually ok even over night. i have heard that a valve sticks in the valve body and the o-ring sticks untill the case warms up enough to let it slide past the worn area then it shifts. Anyone know which one is sticking so i can tear apart to fix. Thanks started at about 55k. now 73k

[hvac1000]

First of all there is a sensor on the engine that sends a temp signal to the transmission as to when to shift depending on the water temp of the engine. I would flush and refill the trans with new fluid. At 73,000 that should have been done according to the maint schedual. When you refill ad a bottle of Schafer trans stuff. I forget the exact name but it sure does work to clean and lube all the trany parts. It is ok to leave in since it does the trans no harm. Been using it for years on problems with trans.

[Damkia]

AFAIK all Sportages had 4 speed auto's... (strange that you identified it as a 3 speed.)

It sounds like you have an electrical problem too with the temp sensor for the ECU/TCM not working properly as this limits the transmission to three speeds and does not allow the transmission to lock up in 4th (overdrive). It sounds like the sensor is giving out the "cold" signal to the ECU which is telling the transmission control module not to engage the overdrive gear (common procedure to prevent overloading the engine when it is cold). I would have a good look at this.

Have you checked the actual level of fluid in the transmission, may need a top up.

I would be looking at exactly how many gears you are going through, as "three" is most definitely the wrong number. If you cannot get to "four" then feel the lock-up of the converter, then your problem is more than likely electrical and not mechanical. You need to get this sorted before you can really start to diagnose anything else. There is a known issue with a splice in the loom, but this usually causes a CEL and code.

PS: unless you REALLY know what you are doing, it is not advisable to pull an automatic transmission apart. They have a habit of coming with their own spare parts...("Where the F*** does this go?????") Trust me, there is a gazillion bits and pieces that could go anywhere....

[kiauser]

Ok i changed fluid and filter when this first started and fluid levels still good, even before this problem started it never tryed to shift into OD.
My owners manual does show a 4speed auto my shifter in the car shows
P,R,N,D,2,L no O.D. or button to shut OD off is this correct. My rpm's at 65 are right at 3000 rpm, 70 about 3200 i always wished it had a OD i did not buy this car new so didnt even think it had OD. it is a 2 door, 2wd with the half top if that changes anything. Ok can you recomend a good service manual i have looked everywhere but the dealer... cant find one. I do all my own maintenance and i have rebuilt a few auto trannys not foreign all american but cant be any different so not worried about that, but pretty sure its not inside. I dont have any codes or lights indicating a problem, just used my scanner to read any codes this week none , but do you need a different one to read the TCM ? Didnt know about a cold circuit for shifting could be my culprit do you know which senser it it using also where is this (splice in the loom ) i should look for. thanks for the help, this is getting interesting now..

[Damkia]

http://www.kia-forums.com/1g-1994-20...iagnostic.html

Has all the details on the loom (not your particular problem as it throws a code when faulty) and the location of the sensor on the thermostat housing (IIRC it is on the RHS)