Major coolant leak - what is this part!?

[BArkward]

Hi everyone! New here and hoping to get some help with a part. A coolant hose blew off the back of the engine and I’m trying to figure out what replacement part to buy. I’ve looked up schematics but still can’t match up what I’m looking at. I believe this hose is coming off of the flange. Pics are taken standing on the passenger side of the engine bay looking behind the engine.

The hose came off of the plastic piece (red arrow)

Blue arrows show where the parts are supposed to connect.

What part do I need to fix this?? Let me know if I need to add any more info.

Thanks for the help!

[PhireSideZA]

Not sure but it looks like there could be a part that has broken off, is it not still perhaps stuck inside the flexible hose? Which engine do you have? 2.0T?

[Jayz691]

Looks,like a hose that someone rigged. Usually, those quick release ends are part of the hose.

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[FatMongo]

Holy cow - thats the hose to the heater core. It looks like it completely failed. They are pretty cheap though - you can get REIN replacements at Rock Auto for $10-15.

[BArkward]

Thanks everyone! Yes I have a 2.0T. I believe the plastic quick release broke off in the flexible hose. Will I need the whole hose or just a replacement quick release?

Once I get the part I’ll have to start the tricky part of actually REACHING it haha!

[Theiceman]

yes its the heater core to coolant flange hose. it can vary by vin so make sure you get the right one. be patient as getting it off the heater core can be a bear, probably better cutting it off by splitting it down its length at the connection if you dont have coolant line removal tool.
you need the whole hose as its bonded to that connector.
its not too bad to get at, just be carefull you dont break the plastic flange, as that is a pain in the ass if that leaks.

[BArkward]

Ok so (hopefully) last question. How do I know if it’s the inlet hose or the outlet hose?? My guess is REIN CHR0651 inlet to flange. Is this right??

[Theiceman]

hard to know as audi just calls it a coolant hose.

[a4audi4fun]

https://www.audiusaparts.com/v-2008-...oses-and-pipes

See if the diagram here is any help

[Theiceman]

https://www.audiusaparts.com/v-2008-...oses-and-pipes

See if the diagram here is any help

It's not in that pic, it attaches to rear flange and goes to the heater core.

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[a4audi4fun]

OK - thought it might have been the one of the one's numbered as "17" which also show under the "Related Parts" - one of those looks the hose between rear flange and heater core that my mechanic had to be replace on mine. They are both preshaped but different part numbers - guessing the "T" might mean the one that attaches to the top of the coolant flange, and "R" means the one that attaches to the rear of the flange.

[FatMongo]

Its one of these two:



https://www.ecstuning.com/b-rein-par...e1819373r~ren/

or



https://www.ecstuning.com/b-rein-par...e1819371t~ren/

[FatMongo]

I believe its the bottom hose in the above post: Rein Coolant Supply Hose

[Theiceman]

I think so too.. only way to be 100% is to call dealer with vin. Ask for price and avxilabity and they will give you part number.

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[Gowking]

Given the price of the hoses vs. shipping I would just buy both. It’s only a matter of time before the other hose goes.

[FatMongo]

I think so too.. only way to be 100% is to call dealer with vin. Ask for price and avxilabity and they will give you part number.

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Not sure what you would need to ask the dealer for. All 2.0 FSI A4s are going to have both those hoses. One goes to the heater core, one comes out of it. The dealer will just give you the part # for each of those hoses - which is listed on the ECS link anyway.

As Gowking said, they are cheap enough to buy both.

[Theiceman]

Audi parts list says it varies by vin..also list does not show p/n . So if not sure they can verify. But if you have time and money to play with, go for it.

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[BArkward]

Thanks everyone so much for your help! It was indeed the bottom hose to the heater core. Took my chances and only ordered that one, turned out to be the right one! We got it swapped out and she’s back on the road.

[Theiceman]

Thanks everyone so much for your help! It was indeed the bottom hose to the heater core. Took my chances and only ordered that one, turned out to be the right one! We got it swapped out and she’s back on the road.

Excellent news.

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