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Torque Converter Not Locking Up

18K views 20 replies 13 participants last post by  early 2010  
#1 ·
Anyone else ever had a problem with the torque converter not locking up on the highway sometimes?
Our X is not locking the torque convter at highway speeds sometimes. It doesn't do it on a regular basis, so i'm sure the dealership will shrug it off when they look at it today. Just wanted to see if its a common problem with this vehicle.
 
#2 ·
Wow. The dealer called and said no codes came up, and it would cost me $140 for them to look inside the transmission. THE FRICKIN THING IS UNDER WARRANTY!! WTF? What can I do about this?
 
#3 ·
Whats the symptom, I have notice something happening with the trans at highway speeds also. It reminds me of a slipping clutch, or it won't shift into the next gear.
 
#4 ·
good topic...... with 101,000 miles, i have noticed a drastic change on my mpg...... cleaned injectors, cleaned throtle intake, mass sensor, new plugs................ it increased mpg just a bit.... i am not a mechanic but found that mpg can be effected on an automatic tranny by the lock converter not doing its thing............ i am just begining to try to determine if indeed its not locking up right...... at 60 mgh i release my foot of the gas and the rpms dont go down?????? i did the 45 mph release gas pedal and applyed brake and it slowly went down to 1,000 rpm..... in streets at 20 mph released the gas pedal and it seems that its not disingaging.????? can some owners with their automatic xterra check the 20 mph test.... release gas pedal and see if rpm's go to idle???? i also replaced my transmission fluid with the idea that the fluid might be worn down and making tranny work harder........

about 1 month ago i noticed when i started the xterra and had it in park..... when i press the brake pedal, there is a sound clicking from the left side of the shifter lever.... everytime i press the brake while in park it clicks........ could this be a switch that also sends a signal to the tranny???????

so those are my 2 questions.....

any ideas or suggestions would be appreciated..

thanks...

also..... today i opened the hood and had some type of engine knock....got a long tube and placed it over the spark plug and found 2 spark plugs that have a loud ping..... what does this mean?????? i have been using 5 w30 oil every 3,000 miles..... i am considering replacing it with 10 w40 due to the extreme heat in the area where i live....
 
#7 · (Edited)
the clicking is a sensor that actually unlocks the automatic transmission shift lever thingy (the lever that puts you in gear) it is a safety precaution so that you dont accidentally shift out of park. in order to shift out of park you have to have your foot on the brake. almost all automatic transmissions now a days have this safety feature.
try this... start your X and try to shift into drive without having your foot on the brake... do this in a large open parking lot just in case... you shouldnt be able to shift out of park... if you can take it to the dealership immediately!!!! something is wrong if you can shift out of park without having your foot planted firmly on the brake pedal.
 
#8 ·
I just recently started having a similar problem. It seems to do it only when the tranny is cold and I hit the highway. I am about 2K away from a tranny fluid change, so I am going to try that first and see what happens.

I already looked and my fluid is still clean, so I assume I have not toasted the torque converter or pumps.
 
#10 ·
Its programmed to not lock the converter up until it reaches acertain temp. Thats normal, so don't sweat it. You'll notice it more as the temps drop for winter. Mine does it after it warms up, etc.
 
#9 ·
My wife didn't listen to the tech apparantely. They wanted to change the trans fluid and filter for $140. At just 31k miles, they really think the fluid needs to be changed because "that usually is the cause of problems". yeah right buddy! This thing just takes the kids to school and makes the grocery gettin' trip once a week. No towing, no offroading, etc. Oh well, I'll wait till it craps out completely. it's a very rare occurance anyways. I swear its the lockup solenoid that is having an intermitant problem.
 
#12 ·
If you are driving down the road at 60 mph and you keep your accel foot constant, tap the brake and watch the R's jump up a few hundred for a second and you will see the tach re-steady itself.

You may not know this but the converter momentarily unlocks when your AC compressor kicks on to lessen the NVH in your vehicle.

The converter will remained unlocked in any OBDII vehicle until it has reached a coolant temp of around 140 or a given time as mentioned prior.

Most of you will experience worse gas mileage this time of year because the gas refineries are adjusting the blends. Most also don't realise that just two mins warm up time each way makes a difference in any larger vehicle.

With it being all aluminum though (the engine block and heads), be sure to take it easy on the go pedal until you are up to operating temperature.
 
#15 ·
that's why i like having auto start in my truck, even on nice days... i like to start it up for a few minutes before i hop in..... either warm up the truck, or cool it down on hot days. plus it gives the dvd player time to get to the movie so my kids aren't stuck watching the previews every time... lol
 
#16 ·
Hmmmm, this is an interesting thread. I have on several occasions where mine does this. It has been in summer and winter during full operating temperature. When I seem to notice it however is at slower speeds while going down a hill. I honestly thought it was a mechanism for slowing the truck down a hill.

Which, this should not be using any fuel when this happens. The engine is just being turned by the spin of the wheels, nothing more.
 
#21 ·
Also it isn't necessarly the engine temp, it is usually the transmission temp that allows the convertor to lock up. They want the oil to get warmed up enough to flow good before allowing lock up. I have enven heard stories that it can hurt the convertor lockup clutch if locked when too cold. I have had aftermarket transmission controllers in a few project vehicles. Stated in the documentation was they will not allow the convertor to lock up until the transmission oil reaches a minimun of 100°F over riding all other convertor clutch logic.