Need help in determining the issue of my 92 300TE24V Wagon. In a nutshell, the HVAC isn't blowing cold air. All the mechanics I've sent my car to cannot seem to locate the source of the problem. They used a dye to locate if there's a leak or hole somewhere but no go. New freon will only last up to a week so definitely there's a leak somewhere. But where?

Has anyone experienced this with this model? Your inputs are appreciated. Thank you!

 

Probably coming from the evaporator. Uggh...that's a HUGE job!

Try fixing it first with some sealant.

e.g.: