AC Compressor & Belt Tensioner Bolt size & length

**jayden.world** · 07-01-2020 08:02 PM

Hello everyone

Could you please let me know what the bolt sizes of the AC Compressor mounting bolt and
the belt tensioner pulley?

I got a new AC Compressor (Denso from FCP) and mounting bolts originally used for my previous AC Compressor are
too short. I could use only 1 bolt out of 3 bolts total. The other 2 are too short.
SHAME ON DENSO for not including the bolts!!!
I didn't know that AUDI B6 B7 S4 has 2 AC compressors and one is at 300w output while the other is 500w.
I think the Denso one is 500w since the mounting bolts need to be longer (same thickness I assume as it needs to be mounted to the engine)

For the belt tensioner pulley, I contacted Audi dealer and they told me that they do not know the size of the bolt
and told me to just buy the whole tensioner pulley which is over $400. (Yeah imagine how I felt from such a great answer they had)

Thank you for your help.

**mholme** · 07-01-2020 09:18 PM

What's the part number for the DENSO compressor? Did you possibly get one from a different model? I only see one part number for the BHF engine.

And the tensioner bolt-it's not available separately, which is probably why they told you to replace the whole thing. I just replaced tensioner recently, I think I saved the old part if you really need specs on the length/pitch.

**jayden.world** · 07-02-2020 12:45 PM

Hi mholme

Could you please give me the spec of the bolt spec/length/size?

For the AC compressor, this is what I bought.
https://www.fcpeuro.com/products/aud...so-4f0260805ah

Thanks

**mholme** · 07-02-2020 04:30 PM

I mean if you're really having a time finding this bolt where you are, I can ship it to you.

Not sure what to make of the AC compressor situation. I'm about to order one too and I would hate to run into the same issue.

**jayden.world** · 07-02-2020 11:49 PM

mholme, thank you so much for your help and I think I may need your help.
I ordered some M4 to M8 bolts with different lengths but they are in Allen Socket type thus I don't know
if those bolts would hold it well. (maybe not perhaps as it is missing washer?)
If the bolts I ordered won't fit or work at all, I will definitely need your bolt and the rivet nut together. My rivet nut maybe is threaded.

Seriously, AUDI bolts are like plaster. So weak. Imagine that I had to spend over $500 on bolts already and still some bolts are missing.
So I got so pissed off and ordered M4-M8 bolts kit but unfortunately it is not a hex/flange type but Allen type and Flat Head type (For valley pan job, etc)

Do you know how much it would cost to ship that to Canada? I can pay with paypal or so for the cost.

BTW, do you know if that's a M8 or M6? Now I know it is 1.25 thread (which I think is the standard for most of the bolts?)
and it is a 1.2 inch in length right?

Also I'm glad that my story helped you choosing your AC. From FCP, they have 2 choices, Nissen or Denso but I bought Denso but Nissen seems to have the right bolt size.
Ask FCP to double check for you if you are ordering from them. (Life time warranty)

Well, my local Audi told me that there are 2 AC versions apparently and 1 is 300w while the other is 500w.
Also that Denso AC does not show what the wattage is but I assume it is 500w as it seems to be bigger than the OEM and the mounting bolt definitely needs to be longer because
the previous OEM bolt is too short. You will have about a nail worth of gap to the engine hole which means the OEM bolt is too short.

**jayden.world** · 07-03-2020 09:37 PM

btw mholme, do you know what the spec of the AC compressor bolts are? I mean, at least the size of the bolt?
Is it M8? M10? M12? I don't think it's any smaller than M8 though.

Thanks!