801252: Replacing BMW i3 air conditioning compressor

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TARDISi3

Active member
Joined
Dec 18, 2020
Messages
29
I received the code "801252 electric a/c compressor: internal fault detected" after diagnosing the a/c no longer working. I have purchased a new compressor and will now be doing a DIY install shortly.

My questions is this; all I have to do are these 6 steps:
1. Reclaim the gas;
2. Remove the old compressor;
3. Install the new compressor;
4. Vacuum the system;
5. Fill system with new refrigerant;
6. Enjoy the cool air?

Does the new compressor come prefilled with the right amount oil?

Is there anything "BMW" specific that I need to do?

Do you have any special advice that I should take?

Thanks!
 
For environmental reasons to perform this replacement, you’d need a evac & recharge AC machine to replace the AC refrigerant & oil. I’m sure they’re $5000, not a DIY project.

A body shop has this equipment, and would be a much cheaper rate vs. mechanical shop or dealer.

Good luck
 
BL5 said:
For environmental reasons to perform this replacement, you’d need a evac & recharge AC machine to replace the AC refrigerant & oil. I’m sure they’re $5000, not a DIY project.

A body shop has this equipment, and would be a much cheaper rate vs. mechanical shop or dealer.

Good luck

Kindly refer to step 1, lol. Can get the reclamation done by my buddy's shop.

Thanks.
 
Might be worth paying for one month's access to BMW's TIS. There are 2 different refrigerant's used depending on country and manufacture date. There is one recommended oil, but apparently the label on some compressors lists an incorrect oil. There seem to be many warnings in the TIS about performing the various steps correctly.
 
alohart said:
Might be worth paying for one month's access to BMW's TIS. There are 2 different refrigerant's used depending on country and manufacture date. There is one recommended oil, but apparently the label on some compressors lists an incorrect oil. There seem to be many warnings in the TIS about performing the various steps correctly.
Thank you for your response, I remember reading about that. My car was manufactured in December 2016 (making it a 2017 year model) for the European market. That means that this car has R1234YF refrigerant. That much I know. Will make sure to have the right oil.

Any other suggestions?
 
TARDISi3 said:
My questions is this; all I have to do are these 6 steps:
1. Reclaim the gas;
2. Remove the old compressor;
3. Install the new compressor; + receiver dryer
4. Install A/C Inline- FILTER
5. Vacuum the system;
6. Fill system with new refrigerant;
6. Enjoy the cool air

Your A/C broke for a reason. Make sure the new equipment lasts longer - get an inline filter somewhere fitted.
BMW for some reasons did not put on in the i3. Most
 
eXodus said:
TARDISi3 said:
My questions is this; all I have to do are these 6 steps:
1. Reclaim the gas;
2. Remove the old compressor;
3. Install the new compressor; + receiver dryer
4. Install A/C Inline- FILTER
5. Vacuum the system;
6. Fill system with new refrigerant;
6. Enjoy the cool air

Your A/C broke for a reason. Make sure the new equipment lasts longer - get an inline filter somewhere fitted.
BMW for some reasons did not put on in the i3. Most
Thanks for this.

Where can I get an inline filter from? I have never heard of these.
 
That is what you usually do on A/C job with a blown compressor.

I've done many compressors on other cars, and you always put in a filter. Because that old compressor might have left metal filings in the system. You don't want have that stuff messing up your new compressor.


For an i3 I have no clue to where got parts from :p

Maybe the i3 has a filter somewhere, I didn't see one in the parts catalogue.
You are the first one tackling this project as DIY. All the best my friend!
 
eXodus said:
That is what you usually do on A/C job with a blown compressor.

I've done many compressors on other cars, and you always put in a filter. Because that old compressor might have left metal filings in the system. You don't want have that stuff messing up your new compressor.


For an i3 I have no clue to where got parts from :p

Maybe the i3 has a filter somewhere, I didn't see one in the parts catalogue.
You are the first one tackling this project as DIY. All the best my friend!

Thanks. I don't think that the dealership would go the filter route either.

In traditional air conditional systems, where would the filter be placed?
 
The dealership would replace ALL A/C components and through that method getting rid of all potential debris in the system.
Guess that's why in the case of an i3 you see A/C repair bills in the 5 digit range.

A debris filter would go before the compressor in the loop, the Accumulator / Receiver dryer, is a filter of sorts.

iu


Next best place is after the condenser, to protect the expansion valves. The position is not super critical, since it's a loop. Just that it gets trapped eventually. Otherwise the stuff makes round after round after round through the compressor and damages it every time a bit more.

I was just looking around and have not found a R1234yf Filter... yet... don't know
In older style A/C system - just google for "r134a filter" yeah don't use a r134a part.
 
eXodus said:
The dealership would replace ALL A/C components and through that method getting rid of all potential debris in the system.
Guess that's why in the case of an i3 you see A/C repair bills in the 5 digit range.

A debris filter would go before the compressor in the loop, the Accumulator / Receiver dryer, is a filter of sorts.

iu


Next best place is after the condenser, to protect the expansion valves. The position is not super critical, since it's a loop. Just that it gets trapped eventually. Otherwise the stuff makes round after round after round through the compressor and damages it every time a bit more.

I was just looking around and have not found a R1234yf Filter... yet... don't know
In older style A/C system - just google for "r134a filter" yeah don't use a r134a part.
Isn't the drier a filter as well?

I found this passive screen. https://airsept.com/Products/Details/32

Do you think that this will help any?
 
I also plan on disassembling the old compressor to see if there are any major parts missing from the spiral vains (or whatever you call it) to see if that is what caused the failure. I'll look for metal shavings.

This thing is electrically driven, so it could be that the electric drive motor burnt out, and there's no debris in the lines.
 
TARDISi3 said:
Isn't the drier a filter as well?

I found this passive screen. https://airsept.com/Products/Details/32

Do you think that this will help any?

The drier may or may not filter debris, depending how it was designed. There a like a bunch of ways of drying refrigerant.
Some of them are chemical binding and some of them work with gravity to leave the moisture in the bottom.

Some driers are in the high side and some are on the low pressure side.
https://www.youtube.com/watch?v=UYVQXrijEPs


Did you find a part number on the i3 drier?

That's a cool set of screens you found there. Those should be easy enough to fit to a compressor inlet.
I mean the new compressor is expensive. So I would take caution to make this last.
 
eXodus said:
TARDISi3 said:
Isn't the drier a filter as well?

I found this passive screen. https://airsept.com/Products/Details/32

Do you think that this will help any?

The drier may or may not filter debris, depending how it was designed. There a like a bunch of ways of drying refrigerant.
Some of them are chemical binding and some of them work with gravity to leave the moisture in the bottom.

Some driers are in the high side and some are on the low pressure side.
https://www.youtube.com/watch?v=UYVQXrijEPs


Did you find a part number on the i3 drier?

That's a cool set of screens you found there. Those should be easy enough to fit to a compressor inlet.
I mean the new compressor is expensive. So I would take caution to make this last.

Thank you for your reply. For the i3 I believe the drier to be on the low pressure side near the front right of the engine bay. I'm not looking for a drier desiccant refill as yet, since I've not cracked the system, nor found metal shavings.

My plan of action is to take off the old compressor and immediately install the new one to reseal the system with only a couple seconds of the system being exposed. Then disassemble to see the condition of the old compressor. That will determine if I need to get a new desiccant or not.
 
Just an FYI - I do seem to remember reading a post by an i3 owner who had the dreaded AC compressor failure, where the Dealer told them the entire system had to be replaced because of metal debris from the failed AC compressor in the lines, with a five-figure repair quote. The guy took it to an independent AC repair shop, where he was told that the dryer acted as a filter in the 'flow'. They just flushed the system and replaced the AC compressor. His last post was that the repair did the job and he had no further AC problems (and a repair bill that was 20% of what the BMW dealer quoted).
 
MKH said:
Just an FYI - I do seem to remember reading a post by an i3 owner who had the dreaded AC compressor failure, where the Dealer told them the entire system had to be replaced because of metal debris from the failed AC compressor in the lines, with a five-figure repair quote. The guy took it to an independent AC repair shop, where he was told that the dryer acted as a filter in the 'flow'. They just flushed the system and replaced the AC compressor. His last post was that the repair did the job and he had no further AC problems (and a repair bill that was 20% of what the BMW dealer quoted).

This is excellent news! I remember reading about the 5-figure quote, but nothing after that. Great news indeed!

How does one flush the system? With compressed air going in the other direction?
 
anytime a A/C system is opened usually the drier is replaced.

When the drier in the i3 acts as filter - that's good information! So you only have to change the drier and the compressor, and can leave the inline filter out.
 
This is excellent news! I remember reading about the 5-figure quote, but nothing after that. Great news indeed!

How does one flush the system? With compressed air going in the other direction?

There were at least two or three posters with the catastrophic AC failure, two at least in Arizona. One poster ended up selling his car as salvage because of the cost of the repair through the local BMW dealer (even though the AC failure was partially the dealer's fault), and the refusal of BMW NA to help out with the cost. The other, in the same area I believe, went and got a 2nd opinion at an independent AC automotive repair shop, and they flushed the system and replaced the compressor, dryer and condenser. I seem to remember hearing that the condenser passages are so small that they actually act as a filter, and trap a lot of any contaminants in the system.

https://www.sundevilauto.com/how-to-flush-car-ac-system/
 
So I have come to realize that there was another failure of the i3 airconditioning compressor earlier this month in this area. The tech that worked on it recognized the color and asked if it was the same car that was in for the replacement earlier.

Anyways, he said that there is a solenoid inside of the compressor that burns out and renders the unit inoperable. With that said, it's unlikely that there will be bits of metal in the system. A relief.

He said that it's a common fault of the type of compressor that he sees at his shop. Not just on the i3.

Regarding my DIY replacement, I have not really progressed on it. I have been thinking about not using 1234 gas when I reassemble. It's very expensive per gram compared to 134. I have been trying to sell my gas to get some money for it...no takers yet.

I'll keep you posted.
 
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