Hello,
Wonder if any of you guys have a suggestion on what is going on. 2005 G35 with 190k miles. Was driving along fine and then when I cranked I noticed the AC went out. After inspection it appeared the AC compressor belt failed. I replaced the belt and the AC was functioning again. I drove around for about a week and then went camping. I spent a long time idling inflating a paddle board and went out on the water. I came back 5 hours later and then cranked the engine. I heard a big decompression sound and then vapor came up from the hood. I looked under the hood and green fluid was all over the belts towards the driver side hose. Was worried I had a coolant leak and was going to be stranded. Then cranked the engine again and drove all the way home (15 miles) with no overheating problem. But the AC no longer functions. The compressor belt is still spinning and turning the compressor. What the hell happened?

Thanks!

 

Sudden vapor from under the hood usually means a hose busted somewhere. Fill up your coolant and start the car and let it heat up as you inspect everything in the engine bay until you find the leak.

The AC might just be a separate issue. But you can fix that later.
Have you checked your coolant level?

 

This was from a cold start. Then instant failure. I checked the main coolant levels and they were good. For good measure I made sure the system still blows hot hair, and it does. I also drove 20 miles or so and the system is stable. The fluid that came out is VERY neon and my coolant is more of a blue-green color. I am thinking its PAG46 oil and there was a catastrophic failure of a seal on the compressor. As the only thing no longer working is the cooling of the AC system. Question is, does the OEM PAG46 oil in the G35 have the florescent die? Looks like its going to be a big job....ARGGG

 

I think u might be right.

 

ok I took off the air intake box to take a closer look and it appears the AC discharge line burst. So the compressor "should" be fine. Question is, what would cause the AC discharge line to burst like that?

edit ok I think I figured out the sequence of events.
When the old belt broke it failed in strips and it whipped around and cut the AC discharge line slightly. The burst is perfectly aligned with the belt. After replacing the belt the weak point expanded for a few days and burst.

So after I replace the line how much PAG oil should I put back in the system to call it "good"?

 

Good find.

You will probably have to pull a vacuum before u fill it up with gas again.

 

EDIT: NVM, you already found out the belt took out the line, FSM calls for 6 oz on a fresh system, you still have oil in the compressor so I'd just add 2 oz which is the typical volume an oil injector holds.

Definitely pull vacuum, use a manifold and make sure it holds vacuum for at least a few hours but keep in mind as the temperature increases the pressure will change so IDEALLY you would pull vacuum in the morning, then check the next morning at the same temperature to make sure it's the same reading on the gauge. Refill with separate PAG46 and separate R134a, put the oil in first then swap to the refrigerant, put 19-20 oz of refrigerant into the system.

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I'm guessing something was rubbing on a line or the condenser got damaged by something coming in the grill. Probably not a pressure issue since the pressure sensor on these cars should have shut the compressor down if it was too high or low.

Since it's apparently already discharged get an R134a manifold, hook it up, adapt and hook an air compressor with about 50psi to the suction side of the manifold, then open the high side and see where the compressor air is blowing out from, once you know EXACTLY where the leak is it will be easier to determine what caused the catastrophic blowout and decide how you want to fix it.

 

man that was an adventure I replaced the line and also replaced the drier since the manual called for it. I read around the net you "don't have to" replace the drier and can pull vacuum on the system for 24h and it should "dry it out". But the science seems to indicate that is false as the drier material would have to heated to 475 F to remove moisture from it. Since its a 10 dollar part I just replaced it.

Just in case anyone else has to do this. I discovered you can replace the drier without removing the radiator, fans and condenser. Just remove the front grill (very easy) and the left 10m bolt holding the radiator to the frame. This gives you enough wiggle room to hit the 10m bolt holding the drier on the condenser from the bottom and boom it comes right off. Takes the drier job from 2h to about 20min.

I vacuumed and charged up the system with 1.5oz of oil and 19oz of 134a and it seems to be blowing cold. Hopefully I did everything right! Thanks for the help guys!

 

Typically I replace driers unless they're less than a year old, for the exact reason you just said, it's a very inexpensive part.