I know there's an A/C thread, but this is a bit odd and thought I'd do my own thread.

So I got the oil changed at a JiffyLube (never again) a couple months ago. The oil change there was more than at the dealership, but that's another discussion, lol.

They checked a lot of things including the A/C, and told me it was low. They tried to sell me a $150 flush and re-charge, which I passed on. The A/C was working ok, btw.

So, 2 weeks ago with the FL summer, I figured I should top off the R134a coolant myself. Went to AuzoZone and got a can of the stuff, the guy there even helped. It made it worse. When it's middle of the day, it doesn't cool much at all.

What is odd, is I hear a fan noise that I hadn't heard before. I had thought it was the compressor, maybe adding new coolant stirred up gook and was clogging something to make the compressor run harder.

I went to the dealership today, no XF techs in on Sat, but one of the service managers looked at it. It's not the compressor, but the cooling fan (for the radiator) running a lot faster than it should be, maybe 2-4 times faster. He was worried I could damage the fan.

Any ideas why adding A/C coolant would make the main engine cooling fan run harder? I'm scheduled to take it back to the dealership Mon, but there's an M/B mechanic I might take it to instead.

Tried to be brief and thanks!