I recharged my freon this afternoon for the first time what I believe since September. I bought the car in February and it hasn't had freon in it yet. When I filled it to appropriate level I noticed a strong rumble sound coming from the engine. It shakes the whole car, but when I get out of the car it sounds normal. I can only notice it when I go to brake and I think its at speeds of 25mph or lower. It might be because the unit on the engine hasn't moved for a good amount of time. I put WD-40 around the outside of it. It seems to have diminished a little bit. Also I see freon around the outside of the unit. I'm not sure if that will diminish also, but I wiped it off and I'm about to take an hour long trip and I'll re-check it when I get there to see how it looks.

Is there a simple solution to the rumble sound?
Is it common for a little leaking when replaced?

I ALSO PUT THE FREON IN THE UPPER CANISTER. I READ SOMEWHERE THAT THIS IS WRONG, BUT IT WAS THE ONLY NOZZLE THAT THE TUBE WOULD LOCK ON TO.

Thanks.

 

Watch the A/C belt at idle with A/C turned on. That's probably where the rumble is coming from. If so, try tightening the belt. Look for any missing braces for the compressor.

What your seeing on the compressor isn't freon, it's refrigerent oil. Once freon hits the air, it turns into a gas very quickly. The oil indicates you have a leak.

The big shiney metal thing with the "nozzle" you can attach to is the receiver/dryer. Thats the ONLY place you should be trying to insert freon.
I would highly recommend a gauge set with gauges for both the "high side" and "low side". It's the only way to tell if the system is working properly.
There's a reason professional mechanics refer to the cheap single gauge setups as "Suicide Kits".

Was the system still under pressure before you started to add freon?

If there was no pressure, there's a good chance you have moisture in the system and the integrity of the dryer will be in question. The dryer can only absorb a small amount of moisture. Any moisture that goes thru the orfice tube will instantly freeze plugging the path for the freon and making the compressor work much harder than normal. Compressors die pretty quick under this condition.

There's a sequence of steps that have to be followed to service an empty A/C system. If not followed, you'll experience lots of wasted time, money and effort; not to mention it can be dangerous.