vt commodore 1999 v6 3.8l

[mustafa76]

Engine Performance problem
1999 Chevy Lumina 6 cyl Two Wheel Drive Automatic

i have lumina 1999 v6 3.8l .my problem is the low performance of engine when the car is getting normal heat. and the transmission is not shiftting to the next gear until rpm reach 3000 or 4000.i check the problem out using computer check and the result : there is no problem in the senssors . i replace all things (fuel pump,fuel filter,spark plugs ,spark wires) and i still have the problem .and i cleaned all of the throttle

some one tel me that it is the Exhaust System.
and other say that it is the transmission becouse the engine have a good power but it is not getting to the drive wheels and the engine sounds like it is working hard but the car is not going anywhere

forgive my poor english

[mustafa76]

no one can help me ?

[accentstencil]

The transmission might need a service or repairs. How many kilometers has the car done and when was the transmission last serviced. Also check the fluid level of the transmission, if it is low that can cause problems.
The engine lacking power could be due to many things but I found that when I renewed my oxygen sensors my car ran much better. Oxygen sensors usually need to be changed every 80,000-100,000 kms because as they get older the lose their efficiency.

[mustafa76]

thanks for replay

as you know lumina 1999 (the name of car in our country ) = vt commodore
do not have Oxygen sensors

i changed the trany oil and the filter 6 month ago and the car still the same the oil color now is red .

and now i have a new problems .

when i put my foot down nothing happens for a few seconds and the trany start to vibrate at 80km until the next shift and the RPM reach 4000 without a god change inthe speed until i remove my foot soo the gear will shift to the next gear .

i did the tech test but there is no error code .
i checked the Exhaust System there is no problem with them .

when the trany start to vibrate at 80km i changed the trany from D TO 3 so the vibration disappears and the rmp go up from 1400 to 2300 .


from a standing start she goes through the gears without problem when the engine is cold. but after that the gear will not shift until the RPM reach 3500 or 4000.

I forgot to mention that these problems start when i replaced engine munts the new engin was Abandent for 8 years .after replacing the engine the car was very very good for 15 min only.after that the engine almost to die then its started to act very bad.

is this trany or engine problem ?


i dont have aprofitional machinist here so i dont want to spend my mony on guessing i want to be sure that the problem is the trany then i will changed it .


and forgive my poor english

[mustafa76]

can any one help me please?

[mustafa76]

plz help me

[wogstyler]

Try getting a tranny cooler from repco. that will keep the tranny oil temp down and could help. You can buy them for under $100 and wont take long to fit up yourself. Are you sure there are no O2 sensors, Majority of cars have them, My vx does and my old vs and all my mates coomodores do too. They are on the exh manifolds or just below them.
Have you had a shift kit or anythin done to auto? could be that playing with shift pionts. Also take of yout throttle body and give that a clean and give the TPS a gd clean n make sure no shit is in there.

[ausrs]

from what i understand ,many of the cars that get sent to the middle east run on leaded fuel ,have No cat converters .............i would assume though that they would have o2 sensors so that the computer would have an idea of what was going on !

am i right in what you are saying
you replaced the engine and mounts ??? if so check the wiring out and make sure everything is where is it supposed to be ,maybe you have a wire or so pinched !

[VTS5]

can any one help me please?

Well,sounds like transmission is slipping badly,cause when u start with cold oil, thickness of the oil helps the gear changes,but once the oil gets warm / hot goes thin and because of the worn transmission bands ,cant create enough pressure to upshift (rough explanation).

So your best bet,will be replacing / over-hauling cars transmission (bands/clutche's etc.).

[mustafa76]

thanks for all of you

now the gear shift when RPM reach 2700 -3200
and i have oil leak from the trany and oil color is radish

whan in p and revs i feel vibration in the trany and the gas seem to be hard

but on the highway when i put my foot down the rpm reach 3500 without any change in the speed or any shift until i remove my foot .

is this signe of slipping?or bad ECU

should i replace or rebuild?

[mustafa76]

any one can help please?

[mustafa76]

i just want to tell all of you that all of my problems ending with replacing the gas pedal wire with new one
because it was stick when the car reaching it normal heat making the TPS sensor hesitating .