The air conditioning in my 2008 G35S sedan with 145,000 miles stopped blowing cold air. I took it to my mechanic to have it checked out. They tell me that the AC system has suffered "black death". That essentially the entire system has black contamination that ruined most of the AC components. They are quoting about $3600 to:

1. Replace the compressor
2. Replace the expansion valve, which apparently involves removing the entire dash (this is one of the biggest costs)
3. Replace the condenser, which apparently is a part of the radiator so the entire radiator has to be replaced
4. Flush the entire system

The quotation is with third-party parts, and they said it is roughly 50/50 parts/labor. I have a few questions:

1. I am interested in knowing the community's opinion on if "black death" is something that happens to G35's?
2. Does this quotation make sense if there really was black death?

Any other insights would be appreciated. The car is sitting at the mechanics, waiting for me to tell them if I want to move forward. Thank you.

 

First time Ive heard of it. I just googled it and its a a real thing though. Im assuming its super rare.

 

"Black death" is just a slang term that means the compressor blew up. AC compressors have multiple pistons connected to a swash plate, they have piston rings, bearings, etc. When something fails it usually fails CATASTROPHICALLY and blows up the pistons and sends a bunch of metal dust and glitter through the entire system. The black color is because water was introduced into the system somehow which oxidized the metal and the dust/glitter/slime will turn a very dark grey color. If there isn't any moisture in the system it will just look like silver colored glitter/slime with a greenish tint from the compressor oil.

Usually this happens by not vacuuming the system down properly when it's being serviced, this will remove all moisture from the system before charging it with refrigerant and oil.

Not using the correct amount of oil is typically the cause of the compressor eating itself, not enough lubrication and it wears out the internals seals.

Regardless though, when a compressor grenades itself the ENTIRE system needs to be flushed and yes several components just need to be replaced. You technically can flush out the entire system, the heater core and condenser however have a LOT of area that's hard to get that metal debris out and any repair shop worth a **** is going to try to replace all those components because if they missed any of that glitter and it's still in the system you WILL eat up another compressor quickly because there's metal being run through the pistons...

About the only thing you can safely reuse is the metal lines that connect compressor to heater core, core to dryer, dryer to condenser. You would usually replace the heater core, dryer, expansion valve, condenser, and the compressor itself.

Most of that cost in your estimate will be labor cost, it's only about $1000 in actual parts but it's going to be probably two full days of labor to fix, then there's refrigerant charge cost which is probably another $500-$800 or so.

 

It just happened to my 2007 G35 at 275k mile. I replaced original AC compressor at 188k miles and then it imploded at about 270k miles, screwing up everything.

My mechanic first started replacing AC compressor...doesn't work (no air, turns out a wire shorted on a control board), replace expansion valve/evaporator core...doesn't work (got air, but not cold), replace AC/radiator....still doesn't work (no cold air). Mechanic sent my car to a EE specialist, a ground wire was bad on a control board....then I get super cold air.

• Four Season AC compressor (OEM cost too much)
• Evaporator core/expansion valve - OEM sells as one piece
• Radiator/AC condenser - OEM sells as one piece (one piece design)
• Aisin water pump - coolant was leaking, separate issue from AC

I paid $3800 to fix all of the above, if my mechanic knew a ground wire was bad, perhaps I might not need to change radiator/AC condenser, maybe or maybe not but I'll never find out. But damn, my entire AC system is like brand new and it's blowing cold *** air.

Call any Infiniti dealer to get OEM part number, search on line and find the cheapest you can get at the moment.

Show this video to your mechanic (I showed to mine before he wanted to charge me more labor to remove entire dash board), much easier way to replace evaporator core/expansion valve.


Good luck!