3.5 ton R22 A/C system with A coil on furnace For Residential

[sushibar]

My outdoor Carrier AC unit(new last May) makes an awful grinding noise on startup or when it cycles about 35% of the time. I had a refrig. guy(people that sold it to me) come and look at it but he couldn't get it to make the sound. One thing he said was my head pressure was low as well, but it wasn't that big of deal. It would come up if he covered the fan a little.

What are some possible cause of noise on startup.?

[AUcooler]

Perhaps outdoor fan hitting cowl. Check the fan cowl for any scraping marks. I'd also suggest outdoor fan motor bearings failing except that its unlikly at twelve months old, unless you live by the ocean.

[sushibar]

Definitley internal in the compressor.

[Gary]

Is the indoor unit above the outdoor unit?

[sushibar]

Indoor unit below outdoor. I had a larger system before. It had an unfixable leak. I had a new outdoor unit installed. The tech said to record the noise that he didn't locate to send to him. Everytime I recorded, up to 12 hrs, those of course weren't the times it was sounding bad.

I am not a refreigeration tech, but I have enough knowledge that something sounds drastically wrong.

Should I just wait until it fails then warranty or be preventative.?

[Gary]

Is the system TXV or fixed orifice?

What size was the old outdoor unit?

Why was it replaced?

Was the indoor unit or coil replaced?

[tradybrad]

perhaps oil return problem