Please help me Diagnose this Coolant Leak

[SkyBlue04A4]

I bought my baby Sky Blue 2004 Audi A4 Cabriolet 14 months ago and fell in love; she has been teaching me about auto repair, and I promised her I would be worthy of her. I've been doing mostly cosmetic work, delving into projects like extracting and DIYing a back window regulator. I've also replaced a few hoses and clamps but then...

...then I failed her. A front-end collision left her relatively intact, but leaking coolant, fast. I had to top up twice before returning to my garage to prevent overheating and now it is like her tomb... I cannot figure out where the leak is coming from, and it's such a bad leak I don't want to risk driving her even a few blocks.

I know very little about auto repair. But here is what I can say about the situation:

Immediately after pouring coolant or water into the radiator tank the fluid will drain down the lower radiator hose . . .
Somewhere within the driver's side front of the vehicle the fluid will escape, pooling in the lower lip of the front bumper before dripping beneath the vehicle . . .
The time from pouring fluid into the coolant tank to fluid starting to drip takes no more than 10 seconds, whether the vehicle is running or not.

It seems the problem might be coming from where the lower radiator hose meets the radiator housing to then supply the radiator, but I am near-totally ignorant. In my dreams the culprit is a clamp or fastener or seal or (insert correct term here) that has completely failed, and locating and replacing the failed component will basically completely solve this problem.

In my nightmares, the radiator itself is shot. (What would this look like? How would I know?)

. . .

I am including screenshots I thought might be relevant from the videos I took. I welcome any requests to provide any further images to help you make your assessment.

dripping off radiator front grill view (SE) 2.jpgdripping underside view (NW).jpgdripping off radiator and pooling front grill view (SE).jpgtop down view zoom.jpglower radiatior hose underside view 1.jpglower radiator hose zoom view.jpg

(i captioned the images with words like underside or front grill to indicate where I was when I took the pics and I used compass directions to show generally where the camera was pointed, if the front of the car is due North. Probably a dumb idea but I hope it makes sense)

Thank you!

-- A future lifetime Audi enthusiast

[DJHoro]

Wrong coolant....I would remove front bumper and clean the area. Then fill her up with water until you find the leak. When leak is found use proper coolant or you can have more cooling problems.

Sent from my Pixel 6 Pro using Audizine Forum mobile app

[EuroxS4]

Why do you insist on making yet another thread for the same issue that numerous members already chimed in on? I fail to understand what your trying to accomplish. New thread will not equal any different answers then what was already said. It probably needs a new rad also you clearly don't give two fucks about this car since your putting that garbage in the cooling system.

For context:

https://www.audizine.com/forum/showt...k-After-Impact

[SkyBlue04A4]

Wrong coolant....

Not to my knowledge, and I've done the research on that.

I would remove front bumper and clean the area.

Do you have any guess where it might be? Removing a bumper is a big job for me, what areas that are covered by the bumper might be the source of the leak?

Then fill her up with water until you find the leak.

Have been.

When leak is found use proper coolant or you can have more cooling problems.

The kind of coolant I used did not cause this problem. Not trying to be ungrateful but please read the full post.

[SkyBlue04A4]

Why do you insist on making yet another thread for the same issue that numerous members already chimed in on? I fail to understand what your trying to accomplish. New thread will not equal any different answers then what was already said. It probably needs a new rad also you clearly don't give two fucks about this car since your putting that garbage in the cooling system.

For context:

https://www.audizine.com/forum/showt...k-After-Impact

Woah! Thank you!! I have had a hell of a time trying to access this forum on my phone. I had no idea my post even went through, can't find a history of it, no notifications etc. and I even purchased a laptop to try and use a more compatible device. I'll check it out now!

[grayjay]

Coolant return pipe is attached to lower radiator with a snap-together fitting that is held on with a large "C" shaped clip (visible in your second picture). Use a flat screwdriver to pull the clip upward and the hose should then be free to pull off the radiator outlet so you can have a better look at it. Likely that the plastic radiator is just cracked somewhere. (non OEM) Replacement radiators are surprisingly cheap. Flush system and use correct pink G12 coolant when you reassemble, green coolant will cause corrosion in an audi.

[SkyBlue04A4]

Coolant return pipe is attached to lower radiator with a snap-together fitting that is held on with a large "C" shaped clip (visible in your second picture). Use a flat screwdriver to pull the clip upward and the hose should then be free to pull off the radiator outlet so you can have a better look at it. Likely that the plastic radiator is just cracked somewhere. (non OEM) Replacement radiators are surprisingly cheap. Flush system and use correct pink G12 coolant when you reassemble, green coolant will cause corrosion in an audi.

Ok, woah there's a lot to unpack in just a fewish words:

1. Thanks for the DIY tip on the C clip, and THANK YOU for the photo callback! Didn't know if my pics did anything more than just show the world I am using the wrong coolant... lol speaking of which:

2. Ok, so the pink G12 50/50 coolant then... weird, it's had green in her since I've had her. But my baby deserves pink i guess. Much appreciated.

3. Now, when you say plastic radiator... are we talking the header tanks or the headers themselves... also I don't really know what those are and how to find them, I may have mentioned "radiator housing" in one of these threads but I didn't really know what I was talking about. Can you tell me if the drip on the far left of the middle of the 3rd photo is coming from what I'm calling a housing and if that is possibly a plastic radiator header tank? That would be a huge help.

4. I have purposefully avoided radiator price research... figured it would be prohibitively expensive. But now you've gotten my hopes up... guess I'll see what they cost

[Mike Tries]

Coolant chemistry is more important than it might seem on the surface. Apparently, it's not just pink-dyed water with alcohol mixed in.

[TobiqueSlang]

Coolant chemistry is more important than it might seem on the surface. Apparently, it's not just pink-dyed water with alcohol mixed in.

That's just what they want you to think.

[Mike Tries]

That's just what they want you to think.

I asked ChatGPT to write a spooky haiku about the nebulous "they" that people always mention when they say "that's just what they want you to think." Here's what it came up with.

They lurk in shadows deep,
Whispers on the wind they send,
Minds they seek to keep.

[calebtbay]

All this hubbabaloo about the coolant made me go look it up.

Green has silicates and phosphate to prevent corrosion but its safe for the lead solder old radiators are made with.

Pink has carboxylic acid to prevent corrosion that would be bad for an old radiator.

So the pink could kill an old radiator but it doesn’t say the green will kill a new radiator. Its all going to be safe for plastics. I would worry the green being designed for an iron block might corrode an aluminum block. It didn’t say that however.

I could only find why you shouldn’t use pink for green and not vise versa. Anyone know specifically what the silicates and phosphate do to harm the engine? Do they just do little to protect from aluminum corrosion and the absence of carboxylic acid leaves it unprotected.

I did see the green is only effective for 1/5th the time the pink is effective.

[old guy]

It's a real shame that the pics are no longer available. But still worth a read. Clicky click®️

Quick summary:

Peak sucks
Don't mix coolants
Use G12

[TobiqueSlang]

I asked ChatGPT to write a spooky haiku about the nebulous "they" that people always mention when they say "that's just what they want you to think." Here's what it came up with.

They lurk in shadows deep,
Whispers on the wind they send,
Minds they seek to keep.

That AI knows it's shit. Illuminati confirmed.

[canonball]

My '05 a4 also had the green stuff in it when I bought it, made me roll my eyes as soon as I popped the hood. From everything I've heard/read it's ok to run in these engines but not as effective as G12. The concern comes from mixing, you do not want to mix the generic green coolant with the pink G12 as this will cause a chemical reaction and do a real heavy number on your coolant system and potentially your engine.

I ran the green stuff in mine for a bit knowing I was going to have to do some work that involved draining my coolant. So when the time came I did a complete coolant system flush and then added in the proper G12 mixture and amount. If you flush you want to make sure the water is coming out is crystal clear after flushing the green stuff before adding any G12.

Goes without saying, but someone feel free to correct me if any of that isn't correct