AC line obstruction common?

[paramax55]

It appears that either I have an obstruction in an AC line, or I have a sticking expansion valve. (15 psi on the low side, 300 psi on the high side, frozen condensor). The AC has been working fine for the 5 years I've owned the car and I've never opened the system to let in any contaminants. So, if it's junk in the lines, the compressor is the only place I can think of for it to come from.

I know I need to flush it out and probably change out the valve, but I've never actually had an obstruction - even with complete compressor failures. Are E53 systems that fragile, or have I finally just gotten (un)lucky after 40 years and countless cars?

[EODguy]

Originally Posted by paramax55

It appears that either I have an obstruction in an AC line, or I have a sticking expansion valve. (15 psi on the low side, 300 psi on the high side, frozen condensor). The AC has been working fine for the 5 years I've owned the car and I've never opened the system to let in any contaminants. So, if it's junk in the lines, the compressor is the only place I can think of for it to come from.



I know I need to flush it out and probably change out the valve, but I've never actually had an obstruction - even with complete compressor failures. Are E53 systems that fragile, or have I finally just gotten (un)lucky after 40 years and countless cars?

Most likely you slugged the condenser. Happens when the compressor starts to die and oil runs through the system. Condensers are cheap enough instead of risking not working after filling.

Don't ask how I learned that...

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[80stech]

It's possible that dessicant can contaminate the system, especially if you have a bag type and the bag starts to break down. Even could be what piles up the compressor.

[paramax55]

I'll check those things. Thanks. It could be either of those things. This is the first vehicle I've had that runs at 4k rpm going down the interstate for 50 miles every day. It's got to take its toll on the compressor.

[X5chemist]

How to remove the desiccant tube. Go to 6:30 time frame. I used a suspension bolt to screw into the top. A small pry bar pulled it right up. I replaced mine last year after a compressor replacement. It was the OEM tube. Only the bottom portion was really ugly.

[paramax55]

Are you serious??? Is that what BMW used instead of a standard filter/dryer??? Can I take off the top cross member to get to it, or do I need to take off the bumper like when I changed the fan?

[X5chemist]

Do you have a M54 engine? If so, you can reach it without removing anything.
Pictures of my compressor installation. Note the OEM tube still has the bolt used to pry it up. A factory sticker covers the tube insert. It's located between the condenser and radiator.