Never having owned a water cooled car or one with air conditioning (besides my Mini) - Admittedly, I know very little about radiators or AC condenser(s).
Can anyone tell me what this fluid might be that intermittently drains from the right front corner of my Mini after running the heat?



My Mini is equipped with Auto AC controls. It's been cold these past few weeks and I have been running the heat without running the AC compresser turned on.
However, I've just started noticing this fluid occasionally leaking during and afterwards.
Whilst wet; I cannot tell if it is coolant/antifreeze or something else expelling from the AC condenser. The fluid does feel a bit oily and a bit sticky when dry. Might this be dripping from AC condenser?
Interestingly - my coolant reservoir never appears to fall below max level and I can find no leaks coming from the coolant/radiator hose (they are new).

Unfortunately, I am currently not in a position to pull the front end/service mode to investigate whether or not I have a punctured radiator.
Perhaps that may be the only plausible way to determine what the source is.

Any clarity or suggestions?

 

You may be looking at the water that normally drains from the condenser when the AC is running. There is a tube that allows that to happen because if there was no drain you'd have a buildup of water that would need to go somewhere- like your interior!

 

The condensate drain for the climate box in more in the center of the car. If this picture was taken with the car on a downward slope or if the car was parked further forward and OP backed up for this picture, then yes, it most likely is the water from the climate unit. Since air conditioning dehumidifies the air in the cabin as it passes through the evaporator, there must be a drain for that water condensed out of the air to go.

The condenser and radiator in the very front of the car should not have any liquids coming from them in a properly operating car. The fact that OP only sees these puddles when the compressor is running leads me to conclude the puddles are the A/C condensation. And the amount of water makes me think he is in humid climate. Here in the desert, the puddles under our cars are not so big.

 

Yes - From what I've read. and have heard; The condensation line from the AC is located more towards the middle of the engine(?). Unfortunately (for me, not having any experience ) I'm inclined to agree with you -The liquid is definitely coming from below the condenser and radiator at the very front/right side of the car.

 

does it have a coolant smell?

the top hose and coolant system bleed valve is right there

 

Funny you should ask - I can't say that I remember what coolant would smell like.
I've been attempting to capture a sample from the leak for hours now since my first post.


Strangely enough, I just haven't been able to reproduce the mystery fluid/leak again to obtain a sample in order to compare it against antifreeze.
I've had noticed a small amount of this fluid dripping previously on one or 2wo occasions over the past few weeks but not nearly as much as pictured in my first post.
Although it dose feel (to my novice senses) that it is coolant. There just hasn't shown to be any source from where it's coming from since it had only drips/leaks on occasion.
It is rather perplexing, that I almost never have to add more than 3-4 oz of coolant to the reservoir (maybe, every 150-250 miles or more), depending on conditions or driving habit.





I'll have to pull the front end when the weather is a bit more tolerable than currently 32°.

 

If you see a puddle again, grab a white tissue and dip it. Then you can tell it's color.

I don't think its aircon related, my guess would be weeping from the water pump.

 

3-4 oz of coolant every 150-200 miles is definitely a leak. Probably something that only leaks a bit when everything gets up to temp, like a small crack in a fitting or end tank. Or a failing water pump, like Lukas said. The thermostat housing on my car cracked years ago, but it only leaked intermittently when everything was hot. When you have the chance to poke around, look for dried coolant residue.

IIRC, the condensate drain is a bit behind the front wheels, offset a bit toward the passenger side from the centerline.

 

@LukasH & @deepgrey - You've read my mind.
Thinking about it after my previous post; I'd remembered a recent discussion regarding an OP replacing a waterpump. We were briefly commenting on the weep hole on the waterpump and it's reasoning as to it's purpose.
I think you're both on to something.

Unfortunately this is just a precursor to what I can expect in the coming days; after arriving to work this morning ....



Hopefully it will continue to be just, a slight dusting, for a short amount of time so I can get the car up on jackstands again.

Thanks!

 

Yep - The flavor Of the day... Good 'ole Prestone green...


After running the car (in park), with the heater on (without Ac compressor); within 30min; I had noticed a drip.
I continued to leave the car running for an additional 1hr-20min. The above pic is shown all that had dripped/leaked out. Definitely antifreeze/coolant.


The above pic shows the level I had topped off my reservoir (2 oz), 2wo days ago, which hasn't changed while the leak had mysteriously stopped
in the last 80 miles since the pic in my first post.

TO BE CONTINUED....

 

If you're able to catch coolant in a cup that small you should be able to look above that spot and see where its coming from, unless its being redirected by a cover. If its as far forward as you show in an earlier picture it might be the radiator. In my experience with other cars the joint between the metal radiator and the plastic end cap are typically the source of leaks.

 

May I suggest that you try not filling the reservoir so full? Just fill to the top of those ribs inside the reservoir. I've found that overfilling causes the system to "burp" excess and, once at the optimum level, it stays there.

 

Ah. Yes a redaction is in order from my previous post. It is pretty common for me to make inaccurate comments/mistakes when posting from my phone (small screen + failure to review befre posting)...
At the risk of coming across as if to back peddle...
Yeah; I just re-read your comment: "3-4 oz of coolant loss per 200 miles" was my mistake. On occasion, I am usually adding about 2-3oz of coolant every 1,500 - 2,500 miles. (I drive long distances a lot).
My confusion: I have a small (concerning) oil leak at my timing chain cover that drips about 3-4oz every 150 - 250+ miles or so. My mistake.

Yep. I overfilled my coolant reservoir this time by about 1/16" just over the ribs/max line. It was more of a test. With the initial amount of "unknown" fluid loss, leaking from an unknown source; It was an attempt to determine if it were a radiator or coolant hose problem/leak.
But to your point - Yes, I agree, (in my experience) overfilling the expansion reservoir will cause issues, if not a leaking cap then possibly splitting the expansion tank at the seam. I've always topped off with coolant only to the very top of the max line when needed..
Thanks for pointing that out. You are right.

 

Has anyone mentioned the Oil Filled Engine Mount yet? From the location it does not appear to be coming from a coolant line however the Oil Filled Engine Mount would be a good candidate.
This one, it has a weep hole check to see if it is obvious that there is a run of oil from it...

Motor On!

 

The motor mount fluid is brown-ish.

 

It is definitely coolant.
I have a pre-facelift rubber engine mount. Not hydraulic.
I've since driven 800 mi and mysteriously it's barely leaked a drop since my last post. Reservoir remains full just slightly below the top of the max/ribs mark.
@RudeJoe maybe right. The drips I'd captured are initially landing on the right side on to the Skid plate/dripping off the lower air dam.
The temps have been in the mid teens - upper 20's this past week. Having no where to work on the car other than finding a vacant lot, Im hoping it maybe a leaking gasket and not a damaged radiator.
Without having yet put the car in the air; I'm trying to understand/trace where and how the reservoir/expansion tank hoses run to and from. *Does the top one drain excess or re- fill the tank? Looks like the upper/top hose routes near under the water pump and to/behind the fan shroud to the radiator?

 

It is a closed loop system. No overflow. Suggest you find/borrow/rent a coolant tester with the Euro adapter that screws on to the reservoir. When the system is cool enough to remove the cap, screw on the tester and pump to 15 or 20 lb. and see if it holds pressure. If it doesn't, you'll find the leak with a good flashlight.

 

Thanks for that info!
I have a (brake) pressure bleeder which came with additional adapters. If Im lucky enough to have a cap/adapter that fits, do you think I could use that bleeder to accomplish pressurizing the system in the same manner?
Thanks.

 

Absolutely! In fact, I use mine when changing coolant to "burp" the system of any air by cracking open the two bleed ports and gently pressurizing until nothing but coolant comes out, then closing the ports.