AT trans problems
Thread Starter
Instructor
Joined: Oct 2012
Posts: 134
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From: Fl
AT trans problems
Hi everyone, I have 99 LS1 AT with about 60k on it. Shorty headers, exhaust, ECS mail in tune. Never tracked, (by me) not abused by me either but I've only had it for a little over a year so theres been lots of room for that.
I recently got some engine issues squared away, and its been running very well for the past month but today I really got on it for the first time in awhile and noticed that instead of shifting at 6k its only hitting 5500 and giving a rough shift as if it got cut off and shifted too early. Also noticeably slower at WOT.
When I first got the mods and tune, it would throw your head back and lose traction pretty good at about 50 when it shifted but now it seems very restrained and slow to rev. Not really off the line but punching it at 40 or 60ish.
Also started to get a little white smoke on start up and found a little oil on the spark plug threads. More so on the passenger side.
I'm about to have to take out a small loan aren't I?
I recently got some engine issues squared away, and its been running very well for the past month but today I really got on it for the first time in awhile and noticed that instead of shifting at 6k its only hitting 5500 and giving a rough shift as if it got cut off and shifted too early. Also noticeably slower at WOT.
When I first got the mods and tune, it would throw your head back and lose traction pretty good at about 50 when it shifted but now it seems very restrained and slow to rev. Not really off the line but punching it at 40 or 60ish.
Also started to get a little white smoke on start up and found a little oil on the spark plug threads. More so on the passenger side.
I'm about to have to take out a small loan aren't I?
Thread Starter
Instructor
Joined: Oct 2012
Posts: 134
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From: Fl
Engine issue was a rough idle, plugs wires, K&N filter, and TB cleaning cured that, Then the ECS tune with a slightly higher idle made it beautiful.
I just drive it about 15 miles to and from work everyday, not too much stop and go either. I've been fixing things since the day I bought it so I haven't had much opportunity to have fun yet.
Le Mans Master
Joined: Jan 2007
Posts: 7,364
Likes: 6
From: Rocky Mount Virginia
You say you didn't abuse it but shifting an A4 tranny at 6k several times is not really too great an idea. It puts a lot of stress on the drivetrain. Even though it is a Vette, those stock auto trannys cannot put up with too much. That aside, if it is gear and it's sluggish, it sounds more like an engine issue than a tranny issue.
Were the plugs you changed out really beat up?(oil, ash,etc) How are the engine/tranny temps during this time?
Were the plugs you changed out really beat up?(oil, ash,etc) How are the engine/tranny temps during this time?
Thread Starter
Instructor
Joined: Oct 2012
Posts: 134
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From: Fl
You say you didn't abuse it but shifting an A4 tranny at 6k several times is not really too great an idea. It puts a lot of stress on the drivetrain. Even though it is a Vette, those stock auto trannys cannot put up with too much. That aside, if it is gear and it's sluggish, it sounds more like an engine issue than a tranny issue.
Were the plugs you changed out really beat up?(oil, ash,etc) How are the engine/tranny temps during this time?
Were the plugs you changed out really beat up?(oil, ash,etc) How are the engine/tranny temps during this time?
Why would the factory set the auto trans to shift at 6k if it couldn't handle it???? Don't a lot of people take their vettes to the track on the weekends and do 4 or 5 runs, maybe even more?
Le Mans Master
Joined: Jan 2007
Posts: 7,364
Likes: 6
From: Rocky Mount Virginia
Another weak link is the rear end/transaxles. They are known to get shredded during a wheel-hop burnout.
Thread Starter
Instructor
Joined: Oct 2012
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From: Fl
I know, it is crazy. You can track the car but the trans will not handle too many runs. This is why so many go to RPM transmissions to get a rebuild. They are a forum vendor and well-respected. A good trans cooler will help. Heat is the #1 cause of the trans to die.
Another weak link is the rear end/transaxles. They are known to get shredded during a wheel-hop burnout.
Another weak link is the rear end/transaxles. They are known to get shredded during a wheel-hop burnout.
Le Mans Master
Joined: Jan 2007
Posts: 7,364
Likes: 6
From: Rocky Mount Virginia
This is very disappointing. So youre telling me this car is only for show and can't really be used?? I've heard such good things about c5s mainly that the engines/trans can take a lot of abuse so a person that only gets on it every now and then could look forward to long life.
-Trans cooler will help longevity
-Differential brace for any wheel hop issues
These are really not expensive and/or hard to install but will improve overall performance and longevity of the drivetrain.
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Thread Starter
Instructor
Joined: Oct 2012
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From: Fl
Don't get me wrong, C5's are excellent cars. Shifting it at 6k once in a while is fine, but if you intend to run it hard a lot, you just need to improve some of the designs. As I said before heat is the killer for auto trannys. Adding these items will help:
-Trans cooler will help longevity
-Differential brace for any wheel hop issues
These are really not expensive and/or hard to install but will improve overall performance and longevity of the drivetrain.
-Trans cooler will help longevity
-Differential brace for any wheel hop issues
These are really not expensive and/or hard to install but will improve overall performance and longevity of the drivetrain.
So your opinion is that the problems I'm having are engine related? I haven't gotten any codes and everything seems fine. Except the early shifting and loss of power at WOT. When I'm driving normally it actually gives a surprising amount of power for only going up to 2000-2500rpms pulling onto a 65mph state road.
I also never drive it until it the air pump shuts off and it reaches 130 degrees, always let it warm up for afew minutes.
I read that a little oil on the spark plugs is ok and so is white smoke every now and again for the first few minutes after start up.
Le Mans Master
Joined: Jan 2007
Posts: 7,364
Likes: 6
From: Rocky Mount Virginia
Ok, well I like the idea of the trans cooler regardless of needing it or not. I will definitely look into that today. Thank you for that.
So your opinion is that the problems I'm having are engine related? I haven't gotten any codes and everything seems fine. Except the early shifting and loss of power at WOT. When I'm driving normally it actually gives a surprising amount of power for only going up to 2000-2500rpms pulling onto a 65mph state road.
I also never drive it until it the air pump shuts off and it reaches 130 degrees, always let it warm up for afew minutes.
I read that a little oil on the spark plugs is ok and so is white smoke every now and again for the first few minutes after start up.
So your opinion is that the problems I'm having are engine related? I haven't gotten any codes and everything seems fine. Except the early shifting and loss of power at WOT. When I'm driving normally it actually gives a surprising amount of power for only going up to 2000-2500rpms pulling onto a 65mph state road.
I also never drive it until it the air pump shuts off and it reaches 130 degrees, always let it warm up for afew minutes.
I read that a little oil on the spark plugs is ok and so is white smoke every now and again for the first few minutes after start up.
Thread Starter
Instructor
Joined: Oct 2012
Posts: 134
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From: Fl
And I need to correct something, its not even hitting 5500k more like 5400 or 5300, pedal to the floor. Which should not be happening.
but it seems normal with low to mid throttle
Also when I say theres oil on my plugs, I meant the ones I took out and the new ones I put in, I checked a couple of them afew days ago and there was some oil on the threads. They were changed less than 1000 miles ago.'
Then theres the white smoke in the mornings, and I'm in FL so its not because of the cold.
Thanks for trying to help me.
Burning Brakes
Joined: Oct 2007
Posts: 1,093
Likes: 33
From: Morristown TN
Trust me you want a trans cooler. There is a small seal separating coolant and transmission fluid in the radiator. It it goes you end up with getting a transmission rebuild. When your coolant jumps up and the tranny starts acting funny, then you pop the hood to see a foamy goo coming out of the coolant tank it is not a pretty sight.
I ended up with a shift kit in mine and it makes a world of difference.
The 1st time I got on it the rear almost got away on the shift from 1st to 2nd and it will bark the tires pretty good going into 3rd if I am driving hard.
I ended up with a shift kit in mine and it makes a world of difference.
The 1st time I got on it the rear almost got away on the shift from 1st to 2nd and it will bark the tires pretty good going into 3rd if I am driving hard.
Ok, well I like the idea of the trans cooler regardless of needing it or not. I will definitely look into that today. Thank you for that.
So your opinion is that the problems I'm having are engine related? I haven't gotten any codes and everything seems fine. Except the early shifting and loss of power at WOT. When I'm driving normally it actually gives a surprising amount of power for only going up to 2000-2500rpms pulling onto a 65mph state road.
I also never drive it until it the air pump shuts off and it reaches 130 degrees, always let it warm up for afew minutes.
I read that a little oil on the spark plugs is ok and so is white smoke every now and again for the first few minutes after start up.
So your opinion is that the problems I'm having are engine related? I haven't gotten any codes and everything seems fine. Except the early shifting and loss of power at WOT. When I'm driving normally it actually gives a surprising amount of power for only going up to 2000-2500rpms pulling onto a 65mph state road.
I also never drive it until it the air pump shuts off and it reaches 130 degrees, always let it warm up for afew minutes.
I read that a little oil on the spark plugs is ok and so is white smoke every now and again for the first few minutes after start up.
Race Director
Joined: Apr 2007
Posts: 11,150
Likes: 890
From: South Western Ontario
It sounds like the engine is losing power to me too. Usually an auto failing will either simply not shift or it will slip during the shift which causes the rpm's to jump until the engine hits the rev limiter.
Thread Starter
Instructor
Joined: Oct 2012
Posts: 134
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From: Fl
I recently sent my PCM to ECS but everything was great when that was first done. Lots of power and it was shifting correctly. Really made a difference actually but no problems at all.