Last year the AC in my 07 civic started getting weak so over the weekend I tried charging it. After I did the AC compressor would kick on for about 2 seconds then click off then back on for a few seconds and off again ect. So now the AC blows warm air so I have been driving with it off and the windows down for now.


Yesterday with the AC off my motor started making a loud rattling kind of a knocking sound then it would stop and sound like normal then it would make the noise again ect. It was doing this at idle but it seemed to go away when driving on the highway.
Anyone know what my problem might be with the noise as that is my first concern then getting my AC working.

 

Loud rattling is often a loose part on the exhaust system.

The A/C is likely overcharged. The correct amount (starting from absolutely empty) is only about 16 oz IIRC. It is best to have a shop empty it and then weigh in the precise amount. Also make sure the condenser fans work.

 

Would the AC being over charged cause the rattling noise? How do I let out some of the charge from the AC? I would prefer to do it myself if possible to save time and money.

 

No it won't be the cause a noise that also occurs with the A/C off.

On a modern small system, the refrigerant charge needs to be within a couple oz of the proper amount to achieve good A/C performance. This is difficult to do yourself.

 

I will take it to a shop in the morning then. Thanks for the help though.

 

A friend of mine who is a mechanic looked at it and said it was my ac compressor pulley bearings. You could see the pulley shaking.
Where can I order the bearing online? My closest Honda dealer is 30 miles away.
Car is a 07 Honda Civic LX 5speed.

 

would it be part # 38900-RNC-Z51
A/C COMPRESSOR (1.8L) for 2007 Honda CIVIC COUPE



A/C COMPRESSOR (1.8L) for 2007 Honda CIVIC COUPE


http://www.hondaautomotiveparts.com/...SOR+%281.8L%29

 

I guess there are no techs on this site.

 

Part # 38900-RNC-Z51 fixed my issue with the noise but my AC wont work still. My mechanic drained and refilled the Freon to about 16oz, he thinks its the magnet that engages the clutch that is bad. When the pulley bearing was bad and wobbling it rubbed on it enough to wear a grove in the pulley and wore the magnet.


The pulley also came with a new clutch and my old clutch was so worn it barely had any material left on it.


So as of now my car is drivable but the AC doesn't work. Might just wait to get that fixed.

 

Honda Automotive Parts


I also need to replace the tensioner assembly... just making a note for myself here.