Where can I buy a trans...fill tube cap for a 2001 VW TDI

Your 2001 VW Jetta is likely equipped with a "sealed" transmission unit. There is no dipstick that you can use to measure the level of transmission fluid in sealed transmissions. Unfortunately, it's a dealer item that needs to be addressed by a qualified mechanic or at a VW dealer.

Fluid Level Checking & Filling To Check:

1. Connect a scan tool to the vehicle to read ATF temperature. ATF checking temperature should be 95° - 113°F (35° - 45°C).
2. Start the engine.
3. Raise and safely support the vehicle.
4. Place a drain pan under the transmission.
5. Allow the ATF temperature to reach 95° - 113°F (35° - 45°C). Automatic transmission fluid inspection plug
   
   
6. Remove the inspection plug from the transmission housing. Fluid is pipe will run out. If fluid continues to drip out, no additional fluid is needed. If only the fluid in the overflow pipe runs out, additional fluid is needed.

To Fill:
Automatic transmission fluid filler pipe

1. Pry the cap from the filler pipe. The cap locking device will be destroyed during removal.
2. Pull the plug from the filler pipe.
3. Add fluid slowly with VAG 1924 or equivalent until fluid runs out of the inspection hole. Install the inspection hole plug.
4. Install the plug in the filler pipe and secure with a new cap.

I believe it's a dealer only issue. Welcome to the wonderful world of VW.

it could need a filter change and oil for the tranny or it could just be low on gear oil

if you can do it yourself get under the car and make sure that the pan bolts are tight if they are look for any hoses going to and from trans make sure that they are all connected and tight even though the fluid never has to be changed there is still a fill tube make sure that the end of the tube that goes into the tranny is secure and tight being that you had alot of engine work done its possible that one or all of these things could be wrong could have inadverntenly loosened it up and forgot to retighten. hope this at least gives you a starting point.

80 mph reads 3000 revs.does that help??

VW automatic transmissions require a special filling tool to fill the transmissions using gravity. They also never recommend a fluid or filter replacement unless a problem is evident. (a leak or shifting problem). They also use a special brown synthec oil that i believe is only available at VW. My advice is to go to a Volkswagen dealer. I'll still tell you how it works. To check the level the vehicle transmission must be cold (not driven at least 8-9 hrs). With a scanner plugged to check fluid temperature in the transmission. RFemove the red cap on the little tube. It's clipped. Once the red cap is removed the black cap can be pulled out. This is the fill tube. This is where the fluid is added using the fill tool. Start the car and remove the 5mm allen screw which looks like a drain. Inside this is a little tube that goes upwards like 3 cm in the pan. (when the oil heats up it expands and leaks out here) With the car running in park, if oil runs out of the pan hole before 35 deg. c there is too much. Let it drain. If no oil leaks at 35 deg. c it's because there is not enough and oil has to be added while the temperature is going up. At 35-40 deg. c oil should spill out ,reinstall the 5 mm allen with the seal, reinstall the filler plug and red cap lock. If the oil is over 26 deg. c before starting your better off waiting till it cools off to have time to add or let drain depending. Strange procedure but the right one.

if the ac system was functioning under a vacuum (it should be), the can should have gotten cold, is there already pressure in the system before you tried ti fill? you have the correct connection if it had a blue cap. it sounds like a possable restricted oriface tube...the instructions will come with new part, USE CAUTION r-134 system repairs can be very dangerous, be sure to remove and store refrigerant before repair...good luck, marty

VW didn't put a "dipstick" on the trans for whatever reason. You technically have to use the VW Vag-Com scanner to properly check the trans fluid level as VW says it has to be checked at a specific temperature. But there is a "shade-tree" workaround. Start the car and leave the engine running the throughout the entire procedure. You have to get the trans fluid warm-a little under normal operating temp. 95F-104F is what you want-you can attain this after letting the car idle for 8 or so minutes. Continuing, leave the trans in park, and make sure you are on as level of a surface as possible. Then loosen the allen plug on the bottom of the trans pan. You will then see another plug. Remove this plug. Fluid should just trickle out of the hole if it is at the proper level. If it trickles out, you are good. If it doesn't you need to add fluid. Add VW spec ATF through the fill port.The fill port on the top front of the trans is capped off by a red cap and is very visible. Very carefully pry the cap off and then wiggle the plug out. I'd highly suggest having a spare red cap on hand-VW dealer has them. Then you can pour fluid into the trans. Add a little bit at at time, and all the while watching for the fluid to tricke out of the trans plug hole. When it trickles out, replace the inner plug and then the outer plug. That's it. Recheck after driving the car for a few miles. FYI- A flud and filter swap on the the VW auto trans takes 3 liters, so keep that in perspective. I hope this helps you out.

They are a sealed transmission, no level check available. You will need to take it to a trans specialist or maybe even the VW dealer if there is a trans issue.