Make: Volkswagen
Model: Jetta
Engine Size: 1.6 TD
Refrigerant Type: R134a
A long time back I converted the car from R12 to R134a successfully. In the process I had replaced the evaporator with an aftermarket unit as the original was leaking. The AC setup has a TXV valve with a capillary tube clipped to the line going into the evaporator. It also had some sort of thermocouple or capillary tube that was inserted into the fins of the evaporator and ran up to the AC controls and tied into the compressor clutch circuit.
The OEM evaporator had a small diameter hole where this was snugly inserted. The aftermarket one did not. I shoved it in between some fins and while that functionally has been working, I have a rattle/vibration from it at certain RPMs which I have not been able to stop.
Any suggestions on how to fix this? I was thinking perhaps I could encase it with some putty or other substance, but I don't want to insulate it or throw off its reading in any way. There isn't any good way to clip or clamp it against a fin that I can see.
Here is the original heater box with the OEM evaporator. You can see the thermocouple coming in from the bottom of the photo.
