Nissan Repair: A/C compressor needs replacement?, 1999 infiniti g20, crankshaft seal

Question
QUESTION: 1999 Infiniti G20 has a loud noise near where the belts are, all belts are OK, car also shakes when driving on freeway and looses speed, or I feel a bit intimidated to speed because of the noise and shaking.  Diagnostics by one shop were the harmonic balancer needs replacement along with the front crankshaft seal, another shop indicates it is the A/C compressor that needs replacement and that is the only thing wrong.  A/C still works right now.  The third shop says let's change the A/C compressor, and the harmonic balancer and see if the noise and shaking will go away, otherwise we will need to continue looking at what is the issue.  I could get a refurbished a/c compressor for 300K, new ones are 700K, should I get this piece fixed first as one of the shops indicates that is all that needs to be done? Would this issue cause my car to shake if I am on the freeway? Help please as I would need to buy the part ASAP, for it to be shipped in the next few days.  Thanks!

ANSWER: Marina,

I would get it looked at by another shop to be sure.  The compressor could be going out and causing the noise and shake.  But, I cannot diagnose without seeing the vehicle.  What I do is to loosen all belts and hand spin accessories to verify what is binding or making noise.  That is what I would do to diagnose the problem.  I would not want to spend money on a compressor when it could be the power steering or alternator.  You need to check to be sure.

---------- FOLLOW-UP ----------

QUESTION: Great thanks, one of the shops removed the belts and indicated it was the compressor making the noise.  And you also mentioned if indeed it is the compressor making the noise it could also cause the shake, thus no need to worry about the harmonic balancer at this time? And get the A/C compressor fixed first and see if the issue is gone? Thanks.

Answer
Marina,

Replace the compressor and the receiver dryer at the same time.  If you don't replace the receiver dryer they will not warranty the compressor.  The compressor wears out and in the process metal particles get into the receiver dryer.  If these parts make their way back around to the new compressor it will damage it.  So, replace both and you will be done.