Thanks for reading this thread
My Bella suffers from the well-known AC grinding (and sometimes "bubbling") noise for some time. I finally decided to do something about it, as I'm not at peace with myself leaving her to suffer.
I read everything I found on this forum, and outside of it, and I still don't have a good understanding of the situation. Here are the facts:
- 159 TBi, from 2010 - so it's at that age of 4-5 years when I heard compressors tend to fail.
- Might be that the grinding gets worse when it's hot outside, but not yet sure.
- I hear the grinding noise when I start the AC (for 5-10 seconds) and then periodically (every 5-10 minutes maybe?). It doesn't stop blowing cold-ish air, so it's not the On/Off switching.
- AC air output has ~12 degrees Celsius, and I understand from the service that is should be 2-3 degrees, so something is definitely wrong. This is even after re-gassing.
- I regassed once in November, pulled out about 370 (mg or ml, don't remember), put in 460. Regassed again today - 350 out, 460 in. In both situations, temperature was the same, before and after (~12-13 degrees Celsius), but the sound was less intense after re-gassing. Pressure test ok in both cases. The services said they cannot do any tests on the compressor.
- Visually, I confirm there is a big roller at the bottom of the engine which starts when the AC is turned on. When it stops, there is a click/bank - probably clutch decoupling.
- Pollen filter is ok - half year old, looking perfect.
- With AC on standstill, engine fan running (or switching to High) for ~10 seconds, then 10 seconds off, periodically. Compressor roller doesn't stop to indicate intermittent AC. Is this fan behavior normal ?
My questions and thoughts:
- Slow gas leak might be the cause for the increasing grinding noise after some time...but then why the 12 degrees Celsius even 3 minutes after fully charging with gas, and pressure test ok ?
- Should I buy a diagnostic interface, and see the pressure it makes when AC is on. Is this correlated to the "health" of the compressor ?
- Is it possible that the grinding indicates a lot of resistance from the compressor ? Maybe it will snap the alternator belt ? Should I just go for a new compressor ? What would be a normal cost for a new part + work ? I would expect 500-800 EUR from my readings.
- Should I spend more money and go to the dealer..could they have some specific testing equipment ? As we all know, official dealer services are usually...to be avoided. Same goes for the local one, near Stuttgart.
- I read about a certain sensor in the front grille, but I don't really understand it's function. Can it affect the AC temperature ? But still, why the grinding sound then ?
I would appreciate any hint or piece of information, as I ran out of ideas.
Thank you !