BimmerFest BMW Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
6,922 Posts
Discussion Starter #1
It's was hot, dry, 90+ degrees today and I just returned from the airport in a lot of traffic. While unloading, I hear this dripping/sizzling sound. So I look under the car and I notice what appears to be water dripping on the passenger side, about even with the rear view mirror. It is coming from the edge of a plastic pan but I can't see the actual source due to the pan. The sizzling sound appears to be the water dripping onto the exhaust and vaporizing. I never noticed dripping from this location before, but more importantly, I have I ever heard this sizzling sound. Is this normal? I thought the AC condensate drips from the engine compartment or near the firewall. This is a bit further back. I usually find a small puddle under the car in the summer but just ignore it as normal. The sizzling sound is what seems unusual. Normal? :dunno:
 

·
Registered
Joined
·
670 Posts
Your a/c is dripping from the condenser. It's probably full of debris - get under it & clean it out with a blast of compressed air!
 

·
Seek to understand,^Value
Joined
·
25,199 Posts
I posted pictures of the two hoses in this AC thread.

I concur with what everyone else says above.

Right around both sides of the transmission are the two black rubber hoses for the AC drain; and the J-shaped outlet is right around the u-joint just aft of the transmission.

 

·
Seek to understand,^Value
Joined
·
25,199 Posts
BTW, this is the main part of the undercarriage AC drain hoses alongside the transmission that is bent at 90°, making it exceedingly difficult to clean out the entire hose with anything mechanical should the AC drain hoses block.

Also note we found out there is no AC drain pan underneath the evaporator coils (which are apparently just above this elbow); this was a shock to me. It apparently means the condensate doesn't "collect", per se ... it just drips out as it drips off the evaporator coils, apparently).
 

·
Seek to understand,^Value
Joined
·
25,199 Posts
Thanx everyone!
Hi Fudman,
I don't know if the 530 is different than the 525 but for me, the picture below shows the entire hose is just about at the back part of the transmission (with the green sticker on it for the transmission fluid to use).

The aluminum "cross member" just behind the transmission is a good focus point if you're outside the car, to see where it would drip.

The only thing is the hot exhaust isn't near there ... ???

 

·
Float On
Joined
·
463 Posts
This is not an intentional hijack of the thread but I wanted to comment on Bluebee's excellent pics and narratives of all parts/areas/assemblies in question. You never cease to amaze me!

The AC drain tubes are an area I've not assessed on my car. I will be doing it today, though.
 

·
Registered
Joined
·
6,922 Posts
Discussion Starter #9
Hi Fudman,
I don't know if the 530 is different than the 525 but for me, the picture below shows the entire hose is just about at the back part of the transmission (with the green sticker on it for the transmission fluid to use).

The aluminum "cross member" just behind the transmission is a good focus point if you're outside the car, to see where it would drip.

The only thing is the hot exhaust isn't near there ... ???


Well, I finally got underneath and it appears that the drain tubes on the 530 are a little bit different than the 525. (Thanx for the pictures, Blue! Very helpful!) My passenger side drain tube opens up directly above the exhaust header! Not a particularly good place to put this. :tsk: Both the driver side and passenger side tubes appeared clear. And that explains the sizzling I was hearing. The condensate apparently hits the header, spatters and sizzles and some spatter falls onto the aluminum heat shield. WRT the water dripping from the plastic pan, I pulled that off and just found the brake lines running above it. It appears that the water dripping onto the alluminum heat shield trickles down to the plastic pan and then drains off. So no issue there. All in all, no problem. Just another e39 idiosynchrasy. :rolleyes:
 

·
Registered
Joined
·
670 Posts
BTW, this is the main part of the undercarriage AC drain hoses alongside the transmission that is bent at 90°, making it exceedingly difficult to clean out the entire hose with anything mechanical should the AC drain hoses block.

Also note we found out there is no AC drain pan underneath the evaporator coils (which are apparently just above this elbow); this was a shock to me. It apparently means the condensate doesn't "collect", per se ... it just drips out as it drips off the evaporator coils, apparently).
And when these drains clog and the condensate backs up, where do you think it goes and what do you think it smells like? The only time I had wet carpets, and the stink, was when I discovered these drains were clogged. I had my indie blow them clear last year and haven't had a problem since.
 

·
Seek to understand,^Value
Joined
·
25,199 Posts
The only time I had wet carpets, and the stink, was when I discovered these drains were clogged.
I wonder HOW the hose is removed...

Does anyone know how this hose is removed and replaced?

Does it screw out? Does it have a clip? Do you have to remove anything to get it off?

It seems to be a straight piece of rubber with an elbow of plastic.

I hate it when people ask "anyone ever remove" but in this case, I'll ask:

Q: Has anyone ever removed this drain hose? How did you do it?
 

·
Registered
Joined
·
6,922 Posts
Discussion Starter #12
I had my indie blow them clear last year and haven't had a problem since.
And how exactly did he blow them clear? My tubes looked clear but I could only see into the open ends. I can't imagine much stuff going into the tubes as there is no negative pressure. Did he just blow straight up into the open ends? I would hate to blow crap back into my evaporator. If he didn't just blow into the tubes, then I'll need to know how to remove the tubes (see Bluebee's question above).
 

·
Registered
Joined
·
670 Posts
And how exactly did he blow them clear? My tubes looked clear but I could only see into the open ends. I can't imagine much stuff going into the tubes as there is no negative pressure. Did he just blow straight up into the open ends? I would hate to blow crap back into my evaporator. If he didn't just blow into the tubes, then I'll need to know how to remove the tubes (see Bluebee's question above).
All I really know is he put it up on the lift, got under it, located the tubes and gave them a couple shots of compressed air then got covered with what he called a lot of water and dirt. This was no scientific project, and the effect was immediate. All I can say is that it is certainly worth taking this simple step before drilling holes in your a/c or tearing open the door panels looking for trouble. I would call this approach the Path of Least Resistance.
 

·
Seek to understand,^Value
Joined
·
25,199 Posts
Copy that! Easy day (when you have compressed air available!). Thanx.
One caveat. I felt my hoses to see if I could feel a debris clog. The rubber (or the thickness is so thin) is such that it's very flimsy.

Not like a balloon but closer to a balloon than you'd expect. This rubber is of a much larger diameter and much thinner sidewall than any of the hoses you have inside your engine compartment.

It's so flimsy that it could blow out like a balloon were you to seal it fully when blowing the compressed air inside.

I doubt you'd seal it fully; but my main point is to be aware that the flimsy feel of these hoses is nothing like the firmness found in the underhood hoses.
 

·
Registered
Joined
·
6,922 Posts
Discussion Starter #16
Good point, BB!

If I see my hose begin to inflate, 1) I definitely have a clog and 2) I'm probably using too much presuure! :rofl:
 

·
Registered
Joined
·
339 Posts
How can we clear the hoses without compressed air? Can I use a pipe cleaner or something to try to clean them out? I think my hoses are all jammed up.
 

·
Registered
Joined
·
6,922 Posts
Discussion Starter #18
You could try a can of compressed air, the type used to clean keyboards. Cheap and low pressure, which won't inflate your tubes :p but may not be enough to clean them either.
 
1 - 18 of 18 Posts
Top