Questions and Answers
Knocking Kia
Q. I have a 1999 Kia Sephia, 1.8 liter DOHC, with about 61,000. I began noticing a strange knocking sound not too long after I change my oil just before I did it recently (so, two oil changes ago a little over 3,000). It was a very quiet knock, but I only seemed to hear it at idle and/or very low RPMs.
Once I would drive the knocking sound went away. I went to a local mechanic and asked some questions. He said it sounded like my A/C compressor was going out. Since then, the knock has gotten MUCH louder and only diminishes, instead of disappearing, when the engine revs higher... although, I have noticed that it knocks less (if at all) when the A/C is on. The A/C is still blowing cold air, by the way. I checked the A/C system the other day with a handy little pressure gauge from AutoZone and it seems to be normal and is not losing any freon.
I don't know if the A/C is the culprit behind all of this, and unfortunately my knowledge of A/C units is slim. I've worked on cars a good little bit and know my fair share for a "back yard mechanic", as it were... but when that guy said A/C I thought, "Oh me."
Any help that you could provide would be most appreciated. Thank you.
Sincerely,
JoshuaA. It's very difficult to diagnose a noise without being able to actually hear it. I did check my TSBs to see if it was a known problem but there wasn't anything pertaining to this symptom.
It is possible the A/C compressor is making the noise. If it's in the early stages of self destructing it could still be doing it's job and cooling the car. One way to confirm if it is the A/C compressor making the noise is to remove the A/C belt and run the engine. If the knocking noise goes away, then you know for sure it is the compressor. If you still have the noise, then it is coming from somewhere else.
Additional Information provided courtesy of ALLDATA
