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Discussion Starter #1
Hey guys. I have a 07 cobalt. I noticed today that my car didn't want to get into 4th gear for the first 10 minutes or so. Do our cars not hit 4th unless certain temperature parameters are met? I know some Toyotas do it needing the engine and trans temps to be above something. I found some info about the converter not locking up until hitting a certain temp. But I am not hitting 4th. Also since I just bought the car 2 weeks ago I checked all the fluids over. And found the trans to be about a quart too full. So I let it drain out the check plug in the side while running. Since I did that I'm pretty confident that the trans is correctly filled and the fluid is good and not burnt. It was 11* when I started the car today so clearly very cold.

Thanks.
 

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Was the transmission at operating temperature and level when you checked it?
 

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Discussion Starter #3
Yes I just got back from driving it for an hour it probably cooled for 10 minutes while I got it up in the air on all 4s then I ran it for a minute while slowly going thru each gear. After I put it in Park and pulled the plug.
 

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Was the transmission at operating temperature and level when you checked it?
So it was running before you pulled the plug, correct? Just verifying what I read.

Our trans won't kick into 4th until it's warm - when I used to drive it in the winter, I would notice the first few minutes of driving in the cold, it wouldn't go into 4th - but like I said - only the first few minutes.
 

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Discussion Starter #5
Yes the car was running when I pulled the plug. The reason I checked the fluid level in the first place was that I notice a pretty firm shift going into 4th a few times in the week I drove it.

And for example today I started it and drove up to the corner filled up with 9 gallons of gas while the car was. running. Then proceeded down the block and it wouldn't shift into 4th. Then the next opportunity it had to get into 4th it went in fine. After that I drove about 6 miles and got on to the highway. Getting on the highway it didn't seem like it wanted to get into 4th I was holding a steady rpm. So I let off the gas and it dropped to 4th and was fine the rest of the trip.
 

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At 60mph you should be revving around 2950rpm in 4th with the torque converter un-locked. Should drop to 2700 upon lock-up.
 

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I've been wrong before and haven't driven the Cobalt in a while because my daughter drives it back and fourth to work. I will try it when she comes home. 2200 seem low to me but like I said I've been wrong before.

This transmission is equipped with an ECCC. The pressure plate does not fully lock to the torque converter cover. Instead, the pressure plate maintains a small amount of slippage, about 20 RPM, in SECOND, THIRD, and FOURTH gears, depending on the vehicle application. ECCC was developed to reduce the possibility of noise, vibration, or chuggle caused by TCC apply. Typical apply speeds are 49-52 km/h (30-32 mph) in THIRD gear and 65-73 km/h (40-45 mph) in FOURTH gear. Full lockup is available at highway speeds on some applications.

---------- Post added at 10:33 AM ---------- Previous post was at 10:17 AM ----------

Did not know the MN5 was built in Canada.

Transmission General Specifications
Name
Hydra-Matic® 4T45-E

RPO Codes
MN5

Production Location
Windsor, Ontario, Canada

Vehicle Platform

Engine/Transmission

Usage
A

Transmission Drive
Transverse Mounted Front Wheel Drive

Maximum Engine Torque
270 N·m (200 lb ft)

Maximum Shift Speed
1-2 6,500 RPM

2-3 6,500 RPM

3-4 6,500 RPM

1st Gear Ratio
2.960:1

2nd Gear Ratio
1.626:1

3rd Gear Ratio
1.000:1

4th Gear Ratio
0.681:1

Reverse
2.143:1

Torque Converter Size - Diameter of Torque Converter Turbine
245 mm

Pressure Taps
Line Pressure

Transmission Fluid Type
DEXRON®VI

Transmission Fluid Capacity - Approximate
Bottom Pan Removal: 6.6 L (7.0 qts)

Complete Overhaul: 9.0 L (9.5 qts)

Dry: 12.2 L (12.9 qts)

Transmission Type: 4
Four Forward Gears

Transmission Type: T
Transverse Mount

Transmission Type: 45
Product Series

Transmission Type: E
Electronic Controls

Position Quadrant
P, R, N, Overdrive, D, I, L

Case Material
Die Cast Aluminum

Transmission Weight Dry
74.7 kg (164 lbs)

Transmission Weight Wet
85.0 kg (187 lbs)

Maximum Trailer Towing Capacity
487 kg (1,000 lbs)

Maximum Gross Vehicle Weight (GVW)
1,826 kg (4,100 lbs)

Ratios

Chain
Final Drive
Effective - Overall

32/38
3.29
3.91

32/38
3.05
3.63
 

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Discussion Starter #9
I've been wrong before and haven't driven the Cobalt in a while because my daughter drives it back and fourth to work. I will try it when she comes home. 2200 seem low to me but like I said I've been wrong before.

This transmission is equipped with an ECCC. The pressure plate does not fully lock to the torque converter cover. Instead, the pressure plate maintains a small amount of slippage, about 20 RPM, in SECOND, THIRD, and FOURTH gears, depending on the vehicle application. ECCC was developed to reduce the possibility of noise, vibration, or chuggle caused by TCC apply. Typical apply speeds are 49-52 km/h (30-32 mph) in THIRD gear and 65-73 km/h (40-45 mph) in FOURTH gear. Full lockup is available at highway speeds on some applications.

---------- Post added at 10:33 AM ---------- Previous post was at 10:17 AM ----------

Did not know the MN5 was built in Canada.

Transmission General Specifications
Name
Hydra-Matic® 4T45-E

RPO Codes
MN5

Production Location
Windsor, Ontario, Canada

Vehicle Platform

Engine/Transmission

Usage
A

Transmission Drive
Transverse Mounted Front Wheel Drive

Maximum Engine Torque
270 N·m (200 lb ft)

Maximum Shift Speed
1-2 6,500 RPM

2-3 6,500 RPM

3-4 6,500 RPM

1st Gear Ratio
2.960:1

2nd Gear Ratio
1.626:1

3rd Gear Ratio
1.000:1

4th Gear Ratio
0.681:1

Reverse
2.143:1

Torque Converter Size - Diameter of Torque Converter Turbine
245 mm

Pressure Taps
Line Pressure

Transmission Fluid Type
DEXRON®VI

Transmission Fluid Capacity - Approximate
Bottom Pan Removal: 6.6 L (7.0 qts)

Complete Overhaul: 9.0 L (9.5 qts)

Dry: 12.2 L (12.9 qts)

Transmission Type: 4
Four Forward Gears

Transmission Type: T
Transverse Mount

Transmission Type: 45
Product Series

Transmission Type: E
Electronic Controls

Position Quadrant
P, R, N, Overdrive, D, I, L

Case Material
Die Cast Aluminum

Transmission Weight Dry
74.7 kg (164 lbs)

Transmission Weight Wet
85.0 kg (187 lbs)

Maximum Trailer Towing Capacity
487 kg (1,000 lbs)

Maximum Gross Vehicle Weight (GVW)
1,826 kg (4,100 lbs)

Ratios

Chain
Final Drive
Effective - Overall

32/38
3.29
3.91

32/38
3.05
3.63

Thanks for all that info.

All I can think that possibly could be the issue is the temperature. There is the slight chance that I didn't have the car perfectly level since my driveway has a slight incline but it's a small incline that you can still push a car up by yourself on. Still with that amount of atf I drained out I wouldn't think that would be enough to have it not shift. My friends cobalt we did the atf in since he was leaking and his car just had a 1 2 shift issue only and was 5 qts low! Maybe I'll check the fluid again when I get home if there isn't any snow on the ground yet.
 

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This is best done on a lift
 

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Discussion Starter #11
I'm starting to think this is all just paranoia and it's the way the lockup engages. I'm used to a lockup that just pops in the lockup on this seems to slowly engage. Reason I have the paranoia is because this car is constantly keeping me busy with minor shit.
 

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I would put a level on the top of the door sill (where the scuff plate is).
 
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