1991 318is M42 Refresh Journey

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Original vs. New Denso Compressor Comparison:

Top Front and Rear Bolt Hole Ear Mounts:
New: 55.1
Original: 55.1 and 55.0 (probably 55.1. I used a cheap measurement tool)

Original Top Front Bolt Ear Mount



New



Original Top Back Ear Mount


New Top Back Ear Mount

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Bottom Bolt Hole Distance (critical!!!). I noticed visually on internet images with several new Denso compressors with different set-up. I took the best visual guess and got it right.

Original: 112.2
New: 112.2

Original


New

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I did bunch of other measurements and basically, it was the correct new compressor body. So, I started to disassemble and swapped out the clutch, bearing and pullley.



Rented this ac pulley and clutch removal tool from local auto shop. Made it super easy.

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New on Left and original on Right. Took the bearing (blue) from new and put it in the original pulley.

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Also used original wire connector from old. Left the hose connectors as-is on new compressor. Ready to be installed.

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For other parts, I used AC Solutions and local AC shop to custom build me hoses that nobody sells.

For AC Solutions parts, I ordered:

• CSF E30 Paralle Flow Condensor
• 13" SPAL Fan
• E30 LHD Interior Lines (2)
• E30 R134a Retrofit Kit (dryer, switch, o-rings)
• E30 R134a Expansion Valve

For custom AC lines, all other lines that were not mentioned above. Some are NLA.

New custom lines. Shop kept original metal connectors and replaced the rubber hoses. The middle hose (from condenser fan to dryer) was 100% new piece as it seems standard fittings.



Comparing old to new before installing. All looks identical.

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As always, took the opportunity to clean and do some other things "while we are in there". So, rewrapped some wires. Washed and cleaned the radiator and area.

For the aux fan wiring, I did take the original wiring and spliced it into the new aux fan so that's its plug and play with 2 speed, etc.

Original


Newly refreshed

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From interior standpoint, just lots of trim and glovebox stuff to take off to and get it ready. Evaporator looks clean and nice. I did test for vacuum. Also, cleaned out the evaporator with AC line cleaner.

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Put it all back together with new parts. And, after doing all the necessary AC procedures (i.e. evacuate, check for leaks, etc), Put in about 30oz of R134a. It's now consistently running around in the 40's. Only been couple weeks and the weather is in the upper 80's. 100's days are gone for the season so got to wait until next year to see how it handles itself during the peak summer heat.

I think it's definitely worth the change. It's nice to know that I have basically a new/refreshed AC system to last for many years ahead. Also, the car is becoming more and more comfortable as a daily.