Ok, here I go… I will try to put everything in order to detail as much as I can on what I’ve been experiencing with the 09G Transmission on my MK5 Jetta 2.5
Problems began like everyone else’s threads, slip-bump from 1st to 2nd, 2nd to 3rd… and sometimes when going down gears.
I began my search over the forum and notice that everyone has talked about the valve body of these transmissions and VW extending the warranty of them. I’ve also found numerous threads of people changing the valve body of these transmissions without any luck on correcting these issues.
Here’s my story so far…
Like 2 months ago, I took the car to a shop to change the transmission fluid and explained a bit my issues to the mechanic.
He changed the fluid and filter and he said that they were no traces of anything that could lead to an hydraulic problem like the valve body, he also said that he put an additive to the transmission oil and that would make the shifting smoother… WRONG…. After a couple of days of driving the car the bump was very noticeable and was getting worst to the point that one day I thought that someone rear-ended me because of that slip-bump when changing gear from 1st to 2nd.
I called the guy and he told me that probably my car needed a transmission oil cooler… WRONG AGAIN… I never talked to that guy again after that.
I called the dealer and ask him about the transmission oil change and my story with the other shop, he said that these transmissions were extremely delicate and needed the correct fluid to operate. He said that I needed to change the oil again with the correct one (VW OEM) and probably needed to change it again after 2000 or 3000 km…because when you do a transmission oil change, you only change like 5 quarts of oil and almost 1.5 liters never comes out. So I needed to do that to get rid of the maximum amount of additive that the transmission may have. I’ve also knew that the other shop used the Motul ATF oil, not the OEM one.
After the fluid change at the dealer, I couldn’t notice any difference in shifting… the bump was still there and the clank when lowering gears, but after like a week I began to notice a difference. These issues were not as often as before; there was a positive progress in shifting, definitely not like when I started.
I still have the slipping and bumping but just in 1st and 2nd… not in 3rd anymore. I will probably go and do the second change to get rid of the Motul and additive remaining’s in the transmission and see what happens.
------Here's where I am TODAY------
I’ve searched about the transmission control module (TCM) and found that some people had problems with the TCM in cars flooded or with sunroof leaks due to the location of the TCM under the passenger seat. My car had sunroof leaks (now repaired) but I will definitely would like to know some more about this to see if my TCM needs to be replaced.
I’ve also found that someone changed the engine thermostat and the transmission problems were gone, but I can’t think of any relation with the thermostat and the transmission shifting. Any ideas?
I live outside the US and therefore can’t claim for the extended warranty. Is for US only.