Hammering sound
My miev has 50 000 km and first started hearing nocking sounds in combination with acceleration from low speeds combined with ac turned on. Since the hammering was of quite high frequency beyond a mechanical passive part it sounded like a small motor not properly fastened. As time went by it became sensitive to small road bumps even when AC off and when going uphill.
AC compressor unit - vibration absorbers broken
Lifted the car and found one of the four tiny chock absorbers under the AC compressor unit between front wheels just above ground had lost its rubber and a few more where aged and about to go as well.
The design is a bit optimistic as the expensive and vital unit has no container or other support and may go wild if more than one of the supports break. The unit is heavy and supports are only about 10-15 mm in diameter.
I think there is no point buying expensive original part with metal bracket included if the quality issue has not been adressed by Mitsubishi.
At least rubber pads of low price should have a separate article number and not be bolted to metal brackets to be replaced.
Replacement absorbers
I have located some absorbers of same length and diameter of 60 shore rubber hardness and will give it a try. The original ones have a waist shape and are extremely soft. It may be a bit more rubber area will transfer more AC vibes to the car body. But better than a fall off and better than a rip off.
Original absorbers are L=15 and D=12 mm with two 15mm M5 end bolts
Part number 1117-1255740 from Swedish comapany
Kuntze D=15 mm and L= 15 mm and Hardness 60° (shore).
Bolt threads are M4 compared to original part M5 but worked ok.
Absorbers with thread M5 and D=15 x L=15 can be found at
www.mecmove.se
Photo documentation
Image - Absorber lost its rubber.
Image - Another about to break.
Image - New absorbers are best installed with brackets removed.
Image - Easiest to fasten the bracket to the AC unit and then to the car body.
Done!
Vibrations are appr same as when new.
Four absorbers = $15. Nuts and washers included.