My 07, when put into drive or reverse from park, has a delay and sort of lurches into gear. Most noticeable first time it's started up but also after idling for a bit. Gears still shift when driving fine and there are no other issues. Took a look at my fluid too, it's starting to get a little dark and has a tiny bit of a burned smell to it. What do I do? I have an appointment for the week after to get it looked at but if I could save some money that'd be great too.

 

Burnt smell is bad, it means clutches and bands(brakes) are slipping

How many miles on this transmission?

All automatics run on fluid pressure, there are no "gears", well there are planetary gears, but not the same as gears in say a manual transmission

The fluid pressure is what engages the clutch packs and brakes, to select ratios, i.e. 1st, 2nd, 3rd, ect.......and Reverse

When you select Drive or Reverse there needs to be 100psi and 150psi respectively of fluid pressure to engage the clutches
If you raise engine RPMs you increase the fluid pressure in the transmission, via the torque converter and front pump inside transmission

So if raising RPMs seems to get it to engage faster then you have a low pressure issue at idle RPMs

If it shifts OK driving, engine at higher RPMs, then it is most likely a pressure issue, not always just most likely

There is the EPC(electronic pressure control) solenoid, the computer uses this to to control the pressure inside transmission.

The Valve body is where all the fluid pressure "lives" and it is routed to the different clutches and bands via the other solenoids in the valve body.
Seals and gaskets in the valve body can start to leak, and overall pressure will go down.

But the valve body can not cause fluid to smell burned, that comes only from clutch and bands over heating because they are either worn out or slipping because of low pressure

A transmission shop can test pressures via ports on the outside of a transmission
They test pressure in all gears as transmission shifts, and also in Park and Neutral
This can tell them/you if the pressure is the main issue or if the moving parts(clutches/bands) are just worn out

 

It's got 144,000 km so about 90,000 miles so its not old. I do find that it takes a bit higher RPM to switch gears (or ratio's). If there's something wrong with the EPC how could I determine that? With what you're saying it really seems to be a low pressure issue. I can't see the clutches and bands being worn out because it's pretty low mileage (but I'm no mechanic by any means so what do I know.) Sounds like Im better off taking it to the transmission guy and not using it in the upcoming week upt to the appointment?

 

90k miles is low so yes should be alot of life left on the moving parts

Well pretty much 99% of all automatic transmission problems are low pressure issues, thats what makes them "go", lol, its the burned smell that caught my eye

2.3l Duratec is a high RPM engine, best torque at 3,750rpms, so it should shift at higher RPMs

Automatics run best when fluid is between 180deg and 200deg, same temps as engine coolant really
Except automatics start to wear out fast when fluid is above 200deg, unlike engines, this is why 2nd trans cooler should be installed on any automatic, IMO, best $65 dollars you can spend, lol

If pressure starts to get low, slipping of clutches and bands happen which creates the heat, which creates more wear which creates more heat,.............ect

Your 2008 5R55E transmission does have a Temp sensor(TFT), which you can see in real time with a reader, like a bluetooth OBD reader connected to your phone, under $40 usually, and a good "tool" to have.

From what I see the codes for transmission temps don't seem to trigger until fluid is at 250degF???, that can't be right but thats what I see
P1718 TFT Stuck in Range High-25OF

 

Second transmission cooler? Does that really work? Sounds like a good idea if I'm already having problems at 90k miles. I do live in Canada so it's often cold here though so I don't know how much it will help.
I do have an OBD reader which I troubleshooted today (blown fuse) so I will check that and see what kind of data I can get from it.