Coolant leak, can't pinpoint

[earhythmic]

Looks like a few coolant threads are popping up along with the cold weather, mine started when I began using the heater more as the outside temp dropped.

I'm leaking coolant from the front passenger area. There's some coolant splatter on the bottom of the intake and a little bit drips from that side of the hood seal when I pop it, which leads me to believe it's not the aux radiator like many have mentioned from searching, but coming somewhere from on top of the radiator. All the hoses look good and there's no dripping from them, only residue from it blowing everywhere while driving. Sometimes steam comes from the area too, but again, hard to pinpoint and it could just be drops hitting the hot engine. It's gotten to the point now that I have to refill the reservoir every other day, especially when parking overnight.

Can anyone point me in the right direction and give me some ideas to explore? TIA.

[DasShane]

there is a coolant line that runs between the airbox and the engine and then wraps around the back. Its the main line that goes to the expansion tank. Its plastic and metal. It can crack and spray coolant all over. Mine blew a couple years back and was driving me crazy trying to find the leak since it was everywhere. Its hard to find because the coolant can harden on it and basically seal it for a short time. If thats your problem its a pretty easy fix. Parts are like $260 bucks if you get it from Audi though.

[earhythmic]

Is that small line that clamps to the side of the air box that then goes from rubber to that stupid hard plastic? That was where my previous leak was, cracked right there at the joint. I replaced that entire run back to the T-connector on the firewall. $10 in hoses and clamps from Monument Auto Parts, F the dealer! I'll take a look and see if that's sprung a leak again. However, there's coolant on the very top of the radiator. Hmmm

[DasShane]

Is that small line that clamps to the side of the air box that then goes from rubber to that stupid hard plastic? That was where my previous leak was, cracked right there at the joint. I replaced that entire run back to the T-connector on the firewall. $10 in hoses and clamps from Monument Auto Parts, F the dealer! I'll take a look and see if that's sprung a leak again. However, there's coolant on the very top of the radiator. Hmmm

Yeah that's the one. I had to do the whole thing plus the expansion tank. It all exploded.

[mark_ma]

there is a coolant line that runs between the airbox and the engine and then wraps around the back. Its the main line that goes to the expansion tank. Its plastic and metal. It can crack and spray coolant all over. Mine blew a couple years back and was driving me crazy trying to find the leak since it was everywhere. Its hard to find because the coolant can harden on it and basically seal it for a short time. If thats your problem its a pretty easy fix. Parts are like $260 bucks if you get it from Audi though.

I think you may be referring to this part... Click ME :)
If so this also happened to me
easy fix

[earhythmic]

My first leak a year ago was coming from the small line that attaches to that small outlet on the part you posted. When replacing the line, the small outlet on that part disintegrated like a cracker! Needless to say, I replaced it, so that part is still newish. I'll take a look again, but I really think it's something else.

Question to possibly put me at ease....if it's the actual radiator leaking, it wouldn't just pool up on TOP of the radiator, would it? More likely to be a hose around there?

[VinnysS4]

My 05.5 s4 started leaking coolant pretty quick with the low temperatures (that and i took the car out and beat on it for the first time) My coolant light came on while leaving work. I happened to have like a half gallon of distilled water in the trunk and i filled it up. Yesterday i went and bought some coolant and drove home. Put the car up on ramps and i couldn't pinpoint the leak to save my life. So i pulled the bumper off and there it was staring right in my face. The front of the radiator on the passenger side at the top was gushing coolant. Nice little crack. I cannot afford to keep buying coolant and nobody carries this radiator locally so i have one on order. It wont be here until Monday so my poor S4 is parked and i have a rental car tomorrow morning. Might want to pull the bumper off and check the radiator for leaks. It only takes like 5 minutes to remove the bumper....

[AudiEmpire]

I appear to have a small coolant leak from the line running next to the air-box too. It appears the leak is coming from the "joint / connection" not a crack or puncture in the hose it self. Hopefully the pictures below are helpful.

http://i229.photobucket.com/albums/e...r/IMG_1991.jpg

http://i229.photobucket.com/albums/e...r/IMG_1989.jpg

[DasShane]

I appear to have a small coolant leak from the line running next to the air-box too. It appears the leak is coming from the "joint / connection" not a crack or puncture in the hose it self. Hopefully the pictures below are helpful.

http://i229.photobucket.com/albums/e...r/IMG_1991.jpg

http://i229.photobucket.com/albums/e...r/IMG_1989.jpg

Yep that's the part I was taking about. Super easy fix.

[earhythmic]

Ya that little line next to the air box is a super easy fix. Don't over pay at the dealer, go to a local auto zone and get some flexible hoses with the correct ID, a couple couplers and clamps. $10 max. Just beware, the OEM plastic elbows (like the big one from the radiator) can potentially crumble like a wet Graham cracker. Mine did.

Regarding the radiator, I have a feeling it's coming from the radiator itself too. I had a mechanic buddy quickly take a look and saw some bubbling near the top of the radiator. I think it's coming from the very edge, where that black plastic seals up the side of the radiator.

It's these sort of things that I refer back to my old thread:
http://www.audizine.com/forum/showth...-move-on-B6-S4

[earhythmic]

Update. I think I pinpointed it.

[DasShane]

that will do it