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Assuming this one is going into the trash why don't you cut it open so we can see those thingies that are the individual runs? I don't doubt they are there, but it would be interesting to see them all gunked up. Then maybe we can keep this thread for all the no heat questions.
A picture is worth a thousand no head threads or something like that.
When diagnosing my B5 A4’s heater problem, I experienced that both hoses connecting to the heater core were about the same temperature. It became clear the no heat transfer was occurring even though there was flow. After removing the core, I carefully removed the end caps. This is what I found:
The baffle between the inlet and outlet sections had broken. There is a bleed hole in the baffle. I assume this is to bleed air from the core by allowing removal of one hose. The hoses are at the top of the core. This makes me doubt the "air in the heater core" issue that is perpetuated on the forums...
How does air get traped below water?
The coolant was taking the path of least resistance. It was flowing directly to the outlet instead of through the core. Yes, the core was plugged. I doubt that any back flushing or chemical treatment would have cured that. Remember that the hose connections are at the top in the installed condition. Sediment doesn't really have much of a chance to escape once it enters.
Last edited by Old_School_Audi; 03-15-2017 at 03:12 PM.
Wow I never have seen the broken baffle like that. Great pictures, the inside plugged up noodles are what i always find. Finally everyone can see, its NOT air, its the cores are junk!
This is a close up of the sediment found in the core. It is sand. Now the people saying you have to use the G12 coolant will tell you this happens because the wrong coolant was used. These are the same people selling the overpriced stuff. They haven't researched modern coolants and why the OEM uses it. High silicate water in Europe is to blame. The US doesn't have this. I use distilled water for mixing anyway.
I say this sand is from the engine block casting process. It's not unusual for sand to remain trapped in an iron block when it was made. This eventually works free and into other lower spots in the cooling system. That is the root cause.
BTW, I use the green Prestone in all my Audis...
Last edited by Old_School_Audi; 02-09-2014 at 02:46 PM.
01-27-2014, 07:54 AM
