AC Condenser Damage - 2015 BMW i3 REX

[kallisti5]

A few weeks ago with it starting to warm up in Texas, I noticed the AC wasn't cooling.
I got a AC valve set, and attempted to check the pressure. 0.

A quick look at the front of the car and I realized the AC condenser took a small stone and damaged it causing a leak.
Looking around online, I found a replacement aftermarket condenser for $65. "easy enough".

Being the lazy guy I am, I called around to a few local non-dealer European mechanics.
None of the local mechanics want to work on the BMW i3 (yet)

Called my BMW dealership. Explained the issue (including the damage), and they said to bring it in, it would be covered under warranty.
As you can guess, 5 days later with $139 in labor, they diagnosed the same issue. (gee, Thanks BMW)
They then confirmed it would not be covered under warranty (since it was "road debris damage")

Their price to change the condenser and recharge the system? $1,975. One thousand, nine hundred, seventy-five dollars.
For the purchase price of 11k, I could almost total the car over a stone


So. I turned them down on principle and am sitting here with an i3 with an empty AC. Since the front of the i3 is "completely open and unprotected" to the condenser, I'm going to try and DIY a solution since I have a bit of AC knowledge.

I'm sure 3 or 4 years down the road i'm going to run into this issue again. I'm going to take some time and document the repair process. The guy at BMW said "we see a few of these a month with this issue."

Thank goodness for:
https://www.newtis.info/tisv2/a/en/i01-i3-94-rex-hat/repair-manuals/64-heating-air-conditioning/64-53-condenser-dryer-with-lines/1VnXfJXXOI

 

[Anonymous]

Some 1/4 inch hardware cloth, and a few zip-ties from Home Depot are cheap protection. You have to take out the frunk box to get good access, but an easy DIY project. Have added the mesh to every car I've had for more than a decade - and never had stone damage to an AC condenser.

 

[kallisti5]

Just spent my lunch break ripping into it. The most difficult part seems to be a black cross-member added by BMW for the US market under the fronk storage bin. It sits right above the condenser/radiator. The service manual says on US cars you have to remove the front bumper and left headlight.

Sure enough. While you can get the cross-member unbolted, you can't slide it out without removing a bracket which is blocked by the left headlight. The sad thing is the cross-member is only 1-2 mm too long to prevent removing it without tearing the front of the car apart.

The conspiracy side of me can't help but think at least some of this is on purpose by BMW to ensure drivers go to the dealership for this expensive service, which is guaranteed to not be covered under warranty.

That hardware cloth idea is lookin' mighty good

 

[kallisti5]

4 hours in. *definitely* going to put the hardware cloth in-front of the condenser. To change the condenser you must:

Warning: By following the steps here, you're taking the continued functionality of your
BMW i3 into your own hands. New electric AC compressors run several thousand dollars.

Don't blame me if you follow my steps and something goes horribly wrong.
Don't assume anything since this is not a normal R134a system.
Don't ask your local auto-part store... they don't know.

If you had all the right parts at hand, this is still going to be a 2-3 day job.
(have backup transportation)

My car specs:
* R134a, REX, non-heat-pump.
* All R134a is missing since it leaked out with damage.
* If you have a slow leak, remove + dispose of R134a properly. (maybe call an AC tech?)

Requirements:
* AC Manifold. Buy new. (Everyone should have one.. handy, also you must not contaminate your system with PAG oil)
* AC Vac Pump. Rent. They say "not for use on electric / hybrid cars". I think they're worried about contamination, however, if you're pulling a vacuum I'm not sure how big of a risk it is.
* Cans of freon matching sticker on car. > 2016 or later... likely R1234yf, 2015 or before likely R134a
* Sanden SP-A2 AC OIL (I think it's POE and *NOT* PAG) (You might need to contact BMW parts for this.. I found a small new can on eBay for $49)
* New condenser. The ports should be sealed, don't open until on car. There is a desiccant built-in so need to keep moisture out of it.
* A garage of tools.
* New / Clean AC oil injector. Don't use reuse one that has been used for PAG-*

Notes:
* The AC is used to cool the battery. If it is hot out, it'll kick on by itself for cooling.
* Without a functional AC, don't level 3 charge.
* Without a functional AC, try not to level 2 charge when car is hot.
* I'm assuming level 1 charging doesn't need the AC
* If you contaminate the system with PAG oil (even trace amounts in used lines) bad things will happen

Steps:
* Remove frunk container.
* Move all fluid tanks out the way.
* Remove both front wheel well plastic panels. (You don't have to take the tires off, start at the top)
* Remove front bumper.
* Remove headlights
* Remove the annoying metal brackets blocking removal of the cross member.
* Remove cross member.
* Remove all ducting.
* Remove cooling fan.
* Gently move radiator out of the way by scooting (prying) it back (it's *TIGHT*) without destroying all the fins.
* Separate radiator from the condenser
* Pull condenser.
* Replace O-rings.
* Put system back together somewhat. (make sure all AC related connectors are attached)
* Attach quick connect lines to High / Low ports.
* Attach Vac to the yellow line.
* Open BLUE + RED. Pull a vacuum on the system
* Close ALL knobs on the manifold. turn the vac off. take note of high/low pressure. Wait 45 minutes.
* Check for leaks (loss of pressure). Any loss of pressure... stop and fix the leak.
* Turn Vac on. Open BLUE + RED valves. Vac out for 60 minutes straight if no issues found.
* Close BLUE + RED AC manifold valves
* Put on leather gloves, engage safety squints. (don't skip this step, R134a to the skin hurts + burns)
* Ensure you have plenty of ventilation. (Don't inhale R134a)
* Disconnect Vac, attach a bottle of *plain* R134a to the yellow line.
* Open can.
* Bleed air from the yellow line by momentarily loosening the connection at the manifold. Watch for flying R134a. Retighten.
* Plug drivers seatbelt in. Sit down. Turn car on. Set MAX AC
* This will let you keep the car running while not sitting in it. Handy for hot texas days as well.
* Slowly open the BLUE LOW-PRESSURE valve. *NEVER OPEN RED HIGH PRESSURE WHEN CAN ATTACHED. It will explode.*
* Gently shake the bottle and watch for freon entering system. My car shows 750g which is 26.45547 oz. That's two full cans == 24 oz.
* Swap cans by shutting LOW valve, shutting can. Detaching, attaching, bleeding freon. Opening can + LOW valve.
* You'll need to weigh the last can. Put on a scale while connected, tare, and try to get as close to the remaining coolant amount as possible.
* Close valves, disconnect. Cold air should be present.
* Add 30 ml SP-A2 oil via an injection tool. (per https://www.newtis.info/tisv2/a/en/i01-i3-94-rex-hat/repair-manuals/64-heating-air-conditioning/64-53-condenser-dryer-with-lines/1LEbCldB) Make sure you bleed out any air from the tool prior to use.
* Work in reverse. See the BMW service manual for bolt torques. To be honest, "very snug" is likely fine for most. I'd torque the cross member though since it is used in a crash.

DO NOT USE PAG-ANYTHING!

BMW was as confusing as possible around the AC oil. It seems like they couldn't make up their minds
on which oil to use since all the documentation is conflicting. (Hell, even the can of BMW AC oil is conflicting.

However, additional research shows PAG-ANYTHING will damage the electric compressor and your car. Even though the SP-A2 is
labeled for R1234yf (and even says *DO NOT USE ON R134a systems* on the can, it is compatible with R134a and R1234yf per this:
https://www.behrhellaservice.com/behr-hella-service/assets/media/Compressor_Oils_EN.pdf

My 2015 has a BMW part number for the AC oil, which matches the can of Sanden SP-A2. My car is also R134a. I feel like BMW were going to have all BMW i3's use R1234yf, but changed their mind to R134a at the last minute for the 2014, 2015 years. The SP-A2 can saying "do not use on R134a" is really saying "don't use it on traditional mechanical compressor vehicles (since it won't mix with PAG-ANYTHING).

To make matters even more confusing, the BMW AC sticker says "PAG 2339920" which when you look up 2339920 you find a the SP-A2 (which i'm pretty sure is a POE oil, not PAG)

The electric compressors require an AC lube with a high "dielectric strength" since it co-exists with the motor windings for the AC compressor. Using something conductive like PAG-ANYTHING will result in arcing within the compressor and damage your compressor/battery.

tldr: use SP-A2 if your car says "PAG 2339920" and DON'T use any PAG.

It's quite a job. I don't blame BMW for the hours... but the parts are still outrageous
With a garage of tools, buying a new condenser, and buying the needed AC tools.. I came out at $300 to repair myself vs the $1,975+ BMW wants. If I was faced with this issue again I'd DIY it again in a heartbeat.

Update: Two weeks of Texas heat, still working fine.

 

[IvanRex]

Congratulations
Looks like a lot of work patience and skill
What would you use to cover the condenser I would love to do it and avoid such an expensive job

 

[Anonymous]

What would you use to cover the condenser I would love to do it and avoid such an expensive job

1/4 inch hardware cloth from Home Depot. Cut to the size and shape of the open black plastic grill in front of the condenser. Mount in back of the plastic grill, and fastened to the grill with black zip-ties.

https://www.homedepot.com/p/Everbilt-1-4-in-x-2-ft-x-5-ft-23-Gauge-Galvanized-Steel-Hardware-Cloth-308231EB/205960850

 

[alohart]

1/4 inch hardware cloth from Home Depot.

Do you feel that a stone less than ¼" in size would not be able to damage the condenser? Woven wire mesh with smaller openings is available but would reduce airflow more.

Not all galvanized metal has a thick zinc layer so rusts fairly quickly in our humid, salty climate. I would be more interested in stainless steel.

 

[Anonymous]

Do you feel that a stone less than ¼" in size would not be able to damage the condenser?

I've been considering that too. Have ordered some of this, to experiment with. Will have to sectioned, as getting the stuff in one long section is really expensive. Will see how it works.

https://www.amazon.com/TIMESETL-Stainless-12x8-inch-30x21cm-Ventilation/dp/B077M93J18/ref=sr_1_6?hvadid=178354298101&hvdev=c&hvlocphy=9026840&hvnetw=g&hvpos=1t3&hvqmt=e&hvrand=418612173151888090&hvtargid=kwd-31814800071&keywords=rodent+mesh&qid=1553290307&s=gateway&sr=8-6&tag=googhydr-20

 

[alohart]

[Have ordered some of this, to experiment with. Will have to sectioned, as getting the stuff in one long section is really expensive.

Are you concerned that the open area of the woven wire mesh that you have ordered is only 52%? In very hot weather, I wonder whether the reduced airflow through the heat exchanger would cause problems.

What are the dimensions of the area that needs to be covered?

 

[Anonymous]

What are the dimensions of the area that needs to be covered?

The open grill area is 32" by 4", experimenting with it.

Bee keeper supply houses also sell galvanized mesh with 1/8th inch opening, so that is all so something to look at too.

 

[alohart]

I have considered attaching some stainless steel woven wire mesh directly to the back side of the black plastic grill whose openings are ~3" x 25". However, the heat exchanger is considerably larger. Maybe the total area of its openings is no greater than the total area of the grill openings such that the grill openings provide more airflow than the heat exchanger can pass at higher speeds. If wire mesh were attached to the back side of the grill, airflow through the grill would be reduced, maybe enough that the heat exchanger would not receive enough airflow to operate efficiently in the hottest weather. Maybe the cooling fan could compensate for this reduced airflow, but I would prefer not to change the behavior of the cooling system. However, if a larger piece of wire mesh were mounted between the grill and the heat exchanger, the mesh might not restrict airflow if its open area is large enough.

Another possibility would be to cut out the closed section of the grill above its top horizontal rib and mount a 4" x 25" piece of wire mesh directly to the back of the grill. The additional airflow due to the greater grill open area might compensate for the reduced airflow of the wire mesh. Mounting the mesh directly on the rear of the grill would make removing leaves and other debris easier.

Thoughts? Suggestions?

A leaf is currently lodged against the heat exchanger in our i3. I've never paid attention to this area. I might be able to dislodge the leaf with a stream of water. However, the area behind the grill is sealed, so the leaf would have to come out through the grill. If a water stream doesn't work, I might be able to fish the leaf out with a long screwdriver, coat hanger, etc.

 

[Anonymous]

Art

In talking to an engineer friend who works with high-end building and equipment AC/ventilation systems, he said that you can (very) roughly estimate air flow reduction of mesh, by taking the surface area that is 'blocked' and subtracting 10%. For example mesh with 50% surface area, and 50% open area would, on average, show a 40% reduction in air flow, 60% open area, 30% air flow reduction.. He also said that reducing air flow to the open grill with a mesh barrier shouldn't be a big deal. He said that the engineering rule is that you always over-engineer components by a factor of 50%. So if an AC system is designed to work in 100 degree + heat in stop and go traffic with limited air movement - considering the normal 50% over-build factor, a mesh grill shouldn't have a much impact on AC operation unless you start getting down to gnat-size protection window-screens.

I ended up ordering a new 'screen' from these guys, as the stainless mesh I ordered to experiment with seemed just too fine:
https://www.customcargrills.com/

This one:
https://www.ebay.com/itm/CCG-UNIVERSAL-6-x-36-SMALL-HEXAGON-ALUMINUM-GRILL-GRILLE-MESH-SHEET-SILVER/190630630977?epid=1638163958&hash=item2c62789641:g:n8cAAOSwovNaJfCt:sc:USPSPriority!75080!US!-1&frcectupt=true

Once I get it, going to look at how easy it is to drop the plastic drag-reduction skid panel under the front of the car, for easier installation access behind the plastic grill (and to remove several leaves )

 

[kallisti5]

The hardware cloth worked wonders.
It really looks best if you install it with the bumper off... which I admit is a pain for such a modification.

I cut out a section and formed it to the inner side of the bumper's air intake. Then I primed it with self etch and pained it black (to hide it a bit better). Took the thin wire wrapping the hardware cloth and used it to tie it to the plastic bumper pieces.

I purposely left the sides open and covered ~90% of the opening (centered) to not restrict all the airflow (but looking at this thread that may not have been needed.

Overall it looks great (if you stoop down and look under the bumper), and I'm pretty sure I won't have this issue happen again

(yes, one of the intake clips are on the wrong side of the bumper there... my desire to have it "perfect" is offset by the work to disconnect the 100 screws holding the bumper panel on

Only downside is you'll need to check it once and a while to make sure it doesn't get blocked by leaves, etc.

 

[alohart]

Thanks for your informative post!

The hardware cloth worked wonders.
It really looks best if you install it with the bumper off... which I admit is a pain for such a modification.

Is it not possible to install the hardware cloth from above or below without removing the bumper?

Only downside is you'll need to check it once and a while to make sure it doesn't get blocked by leaves, etc.

I view this as an advantage because debris that is trapped by the hardware cloth would instead end up potentially blocking the heat exchanger where it is more difficult to remove.

 

[alohart]

In talking to an engineer friend who works with high-end building and equipment AC/ventilation systems, he said that you can (very) roughly estimate air flow reduction of mesh, by taking the surface area that is 'blocked' and subtracting 10%.

That's good to know. Thanks!

Once I get it, going to look at how easy it is to drop the plastic drag-reduction skid panel under the front of the car, for easier installation access behind the plastic grill (and to remove several leaves )

It looks like 10 screws plus an unspecified number of latch mechanisms. I worry about breaking these plastic latch mechanisms.

 

[Anonymous]

Hi Art

I worry about breaking these plastic latch mechanisms.

I agree on that front lower bumper piece - danger of breaking some of the latch things.

The piece I was thinking of taking off is this piece, which looks to be just held in with screws, and should just drop down, which would give access to the grill from underneath/behind.

https://www.newtis.info/tisv2/a/en/i01-i3-hat/repair-manuals/51-body-equipment/51-47-floor-luggage-compartment-engine-compartment-trim-panel/1VnXyQrtvl

Another alternative is to use a paper pattern to accurately cut the mesh to fit in front of the grill opening, edge the grill with rubber trim:
https://www.customcargrills.com/Grill-Trim.asp

...and install it in front of the opening.
https://www.youtube.com/watch?v=dls_a5O6KkE

 

[kallisti5]

A quick side note, i've been keeping those steps updated with how to change the condenser + charge the system.
The AC oil was a horrible mess since BMW is all over the place on what to use. Let me know if anything looks wrong.. I spent way too much time trying to decode what BMW wanted me to use

The car is making 38F air, and the compressor quieted down quite a bit once I injected the oil. Time will tell, but results are positive so far.

 

[Anonymous]

Found that dropping the plastic skid plate under the front of the car does NOT give any access to the rear of the grill area,

But I have figured out how to mount the grill mesh I bought right behind the grill, without doing any dismantling of any part of the front of the car what-so-ever. A little fiddly, and time-consuming, but easily do-able. Will post pics and how-to in the Modifications/Accessories section when I get a chance.

View attachment After 2 r.jpg

 

[alohart]

Found that dropping the plastic skid plate under the front of the car does NOT give any access to the rear of the grill area,

That's too bad. During my brief examination, it appeared that this panel was a bit too far to the rear to provide the needed a access.

But I have figured out how to mount the grill mesh I bought right behind the grill, without doing any dismantling of any part of the front of the car what-so-ever. A little fiddly, and time-consuming, but easily do-able. Will post pics and how-to in the Modifications/Accessories section when I get a chance.

I have my #5 stainless steel woven wire mesh (74% open area) and look forward to reading your installation instructions.

 

[Star63]

I removed the bottom "lip" first. After that it was easy to remove the grill. About an hour for the whole job.
Not bad - but MKH´s method sounds still way easier :roll:

I used painted aluminum screen mesh.