I need some help diagnosing two completely different noises on my 2003 Dodge Dakota 4.7L. One has been present since I purchased it in October, the other fairly new.
Noise 1 - This noise is best described as a "whirring" noise. It never happens when warmed up, only during "cold" starts (meaning the first start of the day, regardless of whether it is 10° or 90° outside). It is not a constant noise, instead seems to be "rotation" related. This is definitely belt/engine driven noise, because if the engine is revved, the noise changes pitch and goes away at a certain rpm. This noise only happens below ~1,000 rpms, and after driving a mile or two, this noise will completely disappear until the next cold start. The only things I can think of are the P/S or A/C compressor (however, this noise occurs regardless of the A/C being on or off).
Noise 2 - This noise is a rather loud groan/hum that occurs when the A/C is first turned on. It happens when the engine is both cold and warm, but worse when cold. It almost sounds identical to what I call "brake drone", it's kind of a deep whine, but not high-pitched. All I know is this is definitely A/C related.
Maintenance - Last but not least, I need to mention what maintenance has been done already. I have done two turkey baster changes (~4 months apart) on the power steering fluid. I used Valvoline ATF+4 to refill the fluid reservoir. As for the A/C, during the first warm days, I noticed excessive cycling of the compressor. Obviously it was low on freon. I hooked an empty can to my gauge to check the pressure. (My gauge is one of the best you can find that comes with a can of freon, but not a "professional" one by any means. I understand I can't rely on it, but it at least gives a good idea.) It was indeed very low. I added two 12oz. cans of R-134a (WITHOUT any kind of dye or stop-leak additive). The first can helped, but not much, therefore I added a second can. It may not be 100% full, but I didn't want to overfill it either. It at least isn't cycling anymore, and blows fairly cold.
Sorry for the novel, but more info usually helps. Thanks in advance!
Noise 1 - This noise is best described as a "whirring" noise. It never happens when warmed up, only during "cold" starts (meaning the first start of the day, regardless of whether it is 10° or 90° outside). It is not a constant noise, instead seems to be "rotation" related. This is definitely belt/engine driven noise, because if the engine is revved, the noise changes pitch and goes away at a certain rpm. This noise only happens below ~1,000 rpms, and after driving a mile or two, this noise will completely disappear until the next cold start. The only things I can think of are the P/S or A/C compressor (however, this noise occurs regardless of the A/C being on or off).
Noise 2 - This noise is a rather loud groan/hum that occurs when the A/C is first turned on. It happens when the engine is both cold and warm, but worse when cold. It almost sounds identical to what I call "brake drone", it's kind of a deep whine, but not high-pitched. All I know is this is definitely A/C related.
Maintenance - Last but not least, I need to mention what maintenance has been done already. I have done two turkey baster changes (~4 months apart) on the power steering fluid. I used Valvoline ATF+4 to refill the fluid reservoir. As for the A/C, during the first warm days, I noticed excessive cycling of the compressor. Obviously it was low on freon. I hooked an empty can to my gauge to check the pressure. (My gauge is one of the best you can find that comes with a can of freon, but not a "professional" one by any means. I understand I can't rely on it, but it at least gives a good idea.) It was indeed very low. I added two 12oz. cans of R-134a (WITHOUT any kind of dye or stop-leak additive). The first can helped, but not much, therefore I added a second can. It may not be 100% full, but I didn't want to overfill it either. It at least isn't cycling anymore, and blows fairly cold.
Sorry for the novel, but more info usually helps. Thanks in advance!