When I turn on by AC, the engine immediately dies and can hear a brief sound that seems to be a belt "squeak." I am assuming it is the compressor seizing the belt upon engaging, but are there any other issues to rule out before I order a new compressor?

Regarding compressors, what is the difference between a 2-groove vs 6-groove when purchasing?

  • 1
    AC compressor is locked up. 2 grove is v belt, 6 grove is serpentine belt.
    – Moab
    Jun 5, 2018 at 20:34
  • Check if your compressor is actually seized. 1)Turn the engine off and keep the key in your pocket or anyway don't make the engine turn on 2)Reach for the compressor in the engine bay and turn its clutch hub (that plate on the front of the compressor clutch assembly) with your own hands. 3)Check for any binding. If it's rotating smoothly, with a little resistance but no lockups at all, then your compressor is good. If it's stuck, or gets caught in any way during rotation, then trash it, have the system thoroughly flushed and replace anything which can't be flushed (some parts can't).
    – Al_
    Jun 6, 2018 at 13:28
  • Among parts which can't be flushed are: the TXV, the receiver dryer, parallel flow condensers, discharge/suction line mufflers, the compressor (obviously). TXVs can still be good if any dirt stopped inside the condenser and the receiver dryer and none at all reached them (i.e. they are clean as a whistle).
    – Al_
    Jun 6, 2018 at 13:30

1 Answer 1


Before buying a new compressor find out what killed the old one. Probably starved of refrigerant and lubricating oil as an educated guess. Check the thermal expansion valve. It could be also a clutch issue. Is it giving a code for a more definitive diagnosis? As for the 2 or 6 groove- Moab already answered that. Thanks Moab...

  • Thanks for the suggestion. I ordered a new Denso compressor with clutch in case there was a clutch issue, as well as a new serpentine belt. I recently checked and added a small amount of R134a so do not believe there was a leak. When I replace the compressor I will take out and clean the condenser as well; I read that a clogged condenser can be a cause also. What are the typical lifespans for an AC compressor? This was the factory part and at 99k miles now.
    – J. Wright
    Jun 6, 2018 at 13:10
  • AC compressors can outlast the vehicle if treated right (kept working on correct refrigerant level, which means optimal oil circulation rate i.e. what comes out immediately comes back; kept from abnormal discharge pressures by keeping the condenser clean and allowing the proper airflow over it; switched on a few minutes a week to make the o-rings and shaft seal not lose any charge; having an AC service done by a pro each 2-3 years and so on). If it seized you'd better change that condenser - parallel flow ones such as yours can't be flushed.
    – Al_
    Jun 6, 2018 at 13:25

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