Hi everybody, this is my first time writing in this forum. I'm from Chile.

I have a pickup truck with a noisy compressor. Almost all of the technichians told me the noise is very low so I should not be concerned with that. But one of them offered me to put a 3GS oil (higher viscoscity?).

He charged again the system with r134 + 3GS (which included fluorescent marker). The noise was reduced considerably, almost to no noise. But, as I've been reading, 3GS is NOT fully compatible with r134.

So the questions are...

What can go wrong with this change?
Is in this case justified using 3GS oil (considering it has a positive effect in the noise)?

The pickup states in a label that r134 + PAG oil should be used.

Regards and thank you!