Pontiac Bonneville Transmisssion
Yeah i just bought a 1999 bonnevile SLE when i first got it the transmission was basicly ruind. My fourth gear was pretty much destroyed. So the dealership replaced it and now its shifting hard and hesitating when shifting into 2nd and 3rd, and bogs down when im going around 30 MPH. People keep telling me to let in get broken in cause its knew but i dont know.
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2014 Malibu 2LT, 2015 Cruze 2LT,
When were the spark plugs changed last?
When were the spark plugs wires changed last time?
My suspicion is that it's the plug wires or the plugs. It probably is lugging at a low RPM in 4th on a slight incline and you accelerate slightly and it's misfiring. Try driving the same circumstance or place with the car in 3 instead of 4. That will keep the motor turning faster and you won't notice the slight misfire.
Or you can do the incline at a lower speed in 3rd at th same RPM and it probably won't do it because in third the load on the motor won't be as great on the same incline because of the lower gearing.
It might be a transmission probably but I doubt it.
You can go to one of the auto parts stores that does free scans for codes on your car and you'll probably have a code for misfiring and it may give a particular cylinder on which it occurs or it may be random misfire. Advance Auto does it in this area. Even though the check engine light is not on there may be a code. If it gets worse the code might cause the light to turn on.
2014 Malibu 2LT, 2015 Cruze 2LT,
The year is 1999 with around 140,000 miles.
One day it shifts fine and the next day it may not.
Do you mean it had one of those flushes where they connect hoses and supposedly change all the fluid without dropping the oil pan and replacing the filter?
If so, did they put in an additive?
2014 Malibu 2LT, 2015 Cruze 2LT,
Does it seem like the firewall under the windshield is jumping up and down? That may mean that a certain part, I believe a Sprague (spelling?) is slipping. Try using 1st gear and see if the same thing happens. I'd recommend against accelerating hard enough to cause that to happen. It may be reduced pressures in the transmission due to wear on the pump. It may be pressure control valve; some of those have had problems. Your transmission has 140K miles and that's good.
2014 Malibu 2LT, 2015 Cruze 2LT,
Jim
Are you running too cool. Without checking a 93 manual and 98 that I have, I believe it won't shift into 4th under the coolant reaches a certain temperature on a cold startup. The obvious reason is pollution control and running faster which heats up the coolant faster decreasing pollution. IF your thermostat is opening too much the motor may be cooling too low and the PCM is doing what it is supposed to do.
I suggest these fairly innocuous reasons it may be doing things strangely, because you haven't said anything about shift quality being back. Late, early, rough upshifts. Strange shifting while cold or coming to a stop aren't mentioned.
If your car has a temperature gauge, follow it to see if things are acting normally. If the thermostat hasn't been changed in a few years, that would be my first suspect.
Are you in a cold climate?
2014 Malibu 2LT, 2015 Cruze 2LT,
Another factor might be the temperature of the fluid is going high and the transmission downshifts out of overdrive.
Are the other three speeds all working completely normally? Can you feel the transmission go into 4th and then the lockup torque converter latch in which reduces engine rpms more?--when the trans operates normally.
2014 Malibu 2LT, 2015 Cruze 2LT,
Or an external cooler can be put in the trans fluid line after the fluid goes though the radiator and keeps the fluid cooler.
The neighbor had towed a boat with his Blazer in 4th gear without a cooler once a year to the Lakes area in Southern Kentucky--mostly interstate, and hurt his transmission with overheating.
I believe you have a 4T60E which means electronic controls. But diagnosis is needed.
Has it had a filter change in the last 30-40 K miles? I hope it's something simple like a solenoid for the torque convert lockup.
2014 Malibu 2LT, 2015 Cruze 2LT,
Where year and model is your car? I am curious if you got an identical transmission or it was a similar model. If you know the model the car came out of, you can call a recycling yard and ask if it's right for your car.
2014 Malibu 2LT, 2015 Cruze 2LT,
Can you describe more about what and when it's doing when you say it stops or if you let off?
2014 Malibu 2LT, 2015 Cruze 2LT,
thanks for the reply.
I asked the transmission specialist where I took the car if more frequent maintenance would have helped, and he said that while I could have gotten a few more miles out of the tranny by more frequent fluid changes ( I was changing at every 30,000 miles), these transmissions start failing at between 125,000 and 175,000 miles. Also, to completely repair the transmission is not cheap, at least not in my particular case, but it was less expensive than the down payment on a new car, and since financing a new car is next to impossible right now, and that I'm not ready to part with my Bonneville, I look at it as a new lease on life.
1994usedbon, may your problem be less expensive and less extensive. The 4T65-E transmission didn't come along until 1997, so your experience may be much different. Good luck!
2014 Malibu 2LT, 2015 Cruze 2LT,
Have the plugs and wires been replaced at the 90-100K mileage as specified in the owner handbook? Plugs AC iridium same as originals?
Are there any other parts that are not working quite right? MAF sensor might be one?
Does the throttle body need cleaning and that extra goop blocking the bleed air around the throttle plate affecting how the IAC can control the very low speed mixture?
Before blaming trans, always make sure the motor is up to snuff. Then it's time to be sure the transmission is doing what it needs.
There also are a few who feel a motor mount wears and allows more movement giving more unevenness to the shifts.
2014 Malibu 2LT, 2015 Cruze 2LT,
Also the engine will sometimes stop running if left to idle for about 10 minutes. Once while the hood was open I noticed a slight puff of air/steam come near the water pump and intake. Any suggestions?
To add to this... the service vehicle soon light comes on and off every few days. It has also been dying when turning slow turns or u turns. I assume the power steering is using up the last bit of power causing it die.
PGFALCON
Do some searching for pressure control module and transmission will not go in gear and see what you can learn.
Good luck.
2014 Malibu 2LT, 2015 Cruze 2LT,
I would consider putting in a new battery just to see if it makes a difference.
I would consider a rebuild an lifetime warranty if it does turn out to be the transmission.
2014 Malibu 2LT, 2015 Cruze 2LT,
I've been having issues with the tranny for about three years. Started because the shop that flushed it said there were no leaks, but caused a leak when they reattached the hose to the bottom of the radiator's cooling reservoir.
I've been waiting for it to just go out... but it's just not happening. It bangs (slips?) into gear-- 2nd to 3rd, sometimes 3rd to 4th --after it's warmed up. I've had it into the shop 3 times, 3 different places, and all of them tell me they don't find anything wrong.
I drive an hour to and from work, 5 days a week, and there are days when I will have no trouble. But then there are days were I will go 5 miles, and it starts doing it. It doesn't make sense to me.
I am tempted to just get it and the motor rebuilt... anyone have any thoughts or recommendations?
When I would be driving and mainly when it was on a up shift it would jerk like it did not want to go into gear or it was confused and didn not know what to do.
I finally went in and had the PCS changed pressure control switch. This took care of the problem has been a year and have had no issues witht he tranny.
hope this helps