E46 Fanatics Forum banner

DIY: A/C Compressor removal and replacement

118K views 46 replies 31 participants last post by  burntoutrubber 
#1 · (Edited)
This is a DIY on the removal and replacement of the Air Conditioning Compressor. I am offering this as a guide and maybe complete or missing information that I consider common sense or I expect people to already know how to do. I am not responsible for any damage you cause your car by doing this DIY. If you decide to do this good luck and I hope it goes well.

I have been working on cars since I was 13 years old and helped my dad restore a 1966 Jaguar Mark X. I also owned an automotive repair shop and what I am doing here is exactly how I would do a client***8217;s car if it came in with this problem.

First let me tell you what happen to my car. I replaced the Evaporator to my car (I did not do a DIY for it, but I posted pics in the forum) and about two weeks later the compressor failed. What the compressor did is locked up and it did it so hard it shut my car off. I turned off the A/C switch and kept on driving until I could buy a new (reman) compressor.

Second the parts and equipment you are going to need is important. Here is a picture of what I bought.
List of needed items: A/C Compressor, Receiver/Drier, and as an extra an Inline filter.

I am going to do a separate DIY on how to install the Inline filter. I recommend this little item makes a difference.

I went ahead and removed all of the Freon by connecting it to an A/C machine. This machine is a must (you can go to an auto shop to have them do it) it is illegal to dump Freon into the air. This machine recovers the old Freon as well as vacuum and recharge.

I went ahead and removed the Belly Pan (I had use of a lift makes the work real easy.lol)

Since I had removed the belly pan You can see the Bad compressor and the Belt Tensioner. Using a tensioner tool remove the belt. The arrow points to the 16mm. nut you attach to the tensioner and remove belt.

I then lowered the car and went to work on getting all of the junk off the top.

You should remove the headlight to get access to the Receiver/Drier

Remove the two 6mm Bolts. Remove the drier but do not replace it yet. You will do this later.

Next go for the removal the two 6mm Bolts that hold the A/C lines on the Compressor.

Here is a Technicians tip for you. Tap the allen tool with a hammer (lightly) into place so it is completely into the allen head. I use socket allens.

After removal of these two bolts you are done for the moment on top of the car. Time to get under the car.

Remove the three bolts and take compressor off of the car.

This is the crucial part of any A/C job. With the Compressor and the drier out you need to flush out the A/C condenser and Evaporator. This really is crucial. I used an alcohol based A/C flush to do this. Here is a picture of what I use to flush out the system. You fill it with flush connect it to air line then put the nozzle on the line that feeds the condenser and spray away till it all comes out clear and no more oil, flush and dirt. You should do it twice at least. Make sure it comes out clean.

Sorry no pictures of me doing the flush. But here is a picture of what was once a blue clean rag covered in dirty oil after the flush. I recommend putting the rag around the opposite line that you are flushing so you don***8217;t make a huge mess.

When you are done with all the flushing go ahead and install the Compressor in the car, just like you took it off. My compressor came filled with oil so I left the cover plates on it so I would not spill the oil. The compressor came with 8 ounces of oil in it. Once you have put the three bolts in go ahead and put the belt back on and the belly pan, you are done under the car.
Now lower the car and install the Drier and A/C compressor lines (lube the new o-rings with a/c oil makes it easier to go in.)

This is the old compressor (I shook the compressor and it had loose parts in it, Threw a rod Internally). I hope this picture helps you understand the compressor set up. Do not forget to reinstall everything you removed to do this job.
The final part to do is Vacuum the system ( I did it for an hour, Florida is humid) and then I went ahead and charged it. The machine I used does everything from one machine and I doubt any of us have one of these at home (they ain***8217;t cheap.lol).

This DIY should give you a full idea of what it takes to do the A/C work and get your car back in the cold. I finished it and now have A/C again. This is not an easy job, but it can be done.

Good Luck and have fun folks.

PM me with any questions about this.

I also want to dedicate this DIY to Andy (Neo328ci) a fanatic taken from us to early in life. I may have not known you, but I always enjoyed your posts.
 
See less See more
10
#34 ·
Are the bolts holding the a/c lines treated with loctite? These bolts, and the ones on the expansion valve take a lot of force to release, and they release with a snap before easily turning out, making me think they are treated with a thread locker.
 
#37 ·
working on this as we speak. woulda been done but have a minor 3 day set back waiting for the right part to come in. for the '99 323i guys like me. Autozone has the wrong dryer / receiver part for our car. we need the 2000 part. its longer , more like a cylinder . they have a short and stubby on file. and there's only (1) screw per a/c hose . and when your filling the compressor with oil, you have to turn the clutch as you pour. overall great write up.
 
#39 ·
guys, I'm trying to replace magnetic clutch, since only the bearing making loud noises, beside that compressor still ok, blowing cold air. but on my way to open the outer clutch plate by removing 10mm bolts, then I seems can't take out those outer plate from the clutch pulley. is there's any other bolts need to removed? your inputs highly appreciated.
 
#40 ·
I did an A/C system rebuild using this DIY and others as a guide. This was very helpful. A few notes about my re-build:

I replaced every o-ring in the system when I disconnected everything. This is never a bad idea, and it is recommended in almost all DIY's that I read.

The expansion valve DIY that is referenced earlier in this thread does not give the job its proper respect as far as degree of difficulty is concerned. The valve bolts to a plate that is not retained axially. It is just a plate that slides freely on the tubes that go to the evaporator. In order to fasten the valve to the plate you must sneak a tool behind this plate to retain it. I used a right-angle pick to do the job. Space is limited and you will be uncomfortable because you are bent over the whole time.

Make sure you take into account the oil that comes shipped inside of the new compressor! I was rushed, and like an idiot, I rotated the pulley on the front of the compressor instead of the plate at the front of the compressor as I tried to pour out the oil and I was surprised (at the time) to see that no oil came out. I did not realize my mistake until everything was bolted onto the car and 8 oz. of PAG 46 oil was added to the compressor and receiver/drier. It is possible that I ended up with more oil in the system than recommended as a result. It turns out that my system worked fine after the vacuum and recharge, but nonetheless it was a silly mistake. Moral of the story-- do not rush!

-John
 
#47 ·
I just finished this job, and this (old) comment is spot on about installing the expansion valve. There is a metal plate that the valve attaches to, but it is not secured, so when you put the valve on, the plate falls backward and you can't get the screws to engage.

I put paper towels behind the plate to make its position firm, put the valve on and screwed it to the plate, then pulled the towels out. Took ten minutes and worked perfectly. Be careful not to get owl between the plate and the valve.

Motor vehicle Automotive tire Tints and shades Auto part Metal


I had to replace the compressor because the oil had drained out and it ceased doing the compressor thing (and blew fuse 63 repeatedly). https://www.e46fanatics.com/threads/fuse-63-blowing-ac-compressor-clutch.1322072/

In case anyone is interested, here is the cost breakdown for the project:
Purple Violet Font Rectangle Material property


** note: the compressor is available for much cheaper here:
 

Attachments

Top