The gurgle in the A/c is from bubbles trapped in the heater core. Common 124 issue. Not a problem, just an issue. If it bothers you, here's how to fix. Take to a dealer where they have hoists where you can lift just the front of the car way up. THen run engine at 4,000+ rpm for about 3 minutes with the defroster and heat on full blast. This will cure the problem.
1988 Mercedes-Benz 260E