Failing Coolant Expansion Tank Hose

[audrobotic]

2022 has been an exciting year for my 9 year old B8.5. Nothing major, just lots of annoying failures. (Coolant tank sensor, coolant tank hose-not the one in the picture below but similar, side mirror ready to fall off, upper timing gasket)

So I was perusing my engine today and noticed this bad boy:

IMG_0047.jpg

If you can see in the picture - the little hose is splitting at the connection point, and there is also some weird crust spot on the hose.
It's seems to be this part: 8K0121081AH

https://www.ecstuning.com/b-genuine-...e/8k0121081ah/

Couple questions - the hose connects to the engine flange, is that difficult to access? Is this an issue that needs to be fixed like in one day, or a couple weeks? I'm gonna be busy with work for the next month, so wondering how high to prioritize this one.

[A4B8 2.0tfsi]

Put a hose clamp on it, and stop worrying about it.

[mrg_B8TFSi]

That other side of the hose goes to the rear coolant flange on the back of the head under the vacuum pump and HPFP.. it’s a little bit of a pain to get to.. but if you replace the hose you should replace that flange too, because it’s plastic and prone to break and it’s coming up on years of use. The crust is the G13 coolant it’s designed to cake up to seal a leak when exposed to air it will self seal. The parts are not expensive when it comes to Audi parts . That slight leak isn’t a big deal you probably have a quite a bit of time it’s not critical yet.. just keep an eye on it and your coolant level


Sent from my iPhone using Audizine Forum

[audrobotic]

Great info! You’re on point with Naptown Tuner, found some videos on this topic.
His videos are awesome, a jedi master on the B8. (but best to skip the non-automotive videos.)

https://m.youtube.com/watch?v=zU92vqGQypw

[Kolbenringe]

Great info! You’re on point with Naptown Tuner, found some videos on this topic.
His videos are awesome, a jedi master on the B8. (but best to skip the non-automotive videos.)

https://m.youtube.com/watch?v=zU92vqGQypw

Yeah, the guy is a conspiracy/QAnon nut and pretty much his life is falling apart due to being immersed in that world and it's getting worse. We're not going to see much in the future from him for sure, so be sure to save the videos because he's liable to lose his mind once and for all one day and pull the videos, set them to private, or try to delete the channel after getting raided by the FBI, etc.

As for the hoses, I recently had an issue with my forward hose where the wire retainer was weak and vibrated to a nearly fully unlocked after driving for hundreds of kilometers on roads with thick ice. The retainer really felt weak.

[audrobotic]

Yikes. Yeah I'll have to save those B8 videos, because they can come in handy in the future.

Can't you just snap that wire retainer back in? I think I've seen aftermarket replacements for the retainers, other wise I guess you just have to replace the whole hose. I had to replace the forward also a few months ago because of a leak in the hose. Also had to replace the expansion tank because of the integrated sensor going bad, with the dashboard message saying "stop engine, coolant..." something like that - but coolant level was fine.

[Kolbenringe]

Yikes. Yeah I'll have to save those B8 videos, because they can come in handy in the future.

Can't you just snap that wire retainer back in? I think I've seen aftermarket replacements for the retainers, other wise I guess you just have to replace the whole hose. I had to replace the forward also a few months ago because of a leak in the hose. Also had to replace the expansion tank because of the integrated sensor going bad, with the dashboard message saying "stop engine, coolant..." something like that - but coolant level was fine.

I did and drove back from the Arctic to central Europe without further incident, but it doesn't feel strong anymore, so it's going to be a hose replacement. They're like 14 Euros here.

And yeah, not a joke about the Naptown guy and the FBI. He's solidly in that direction and becoming more paranoid and militant, so we really should be downloading his videos and hope he doesn't do something stupid, but he's pretty much broadcasting his mental deconstruction and the deconstruction of his life for conspiracies.

[audrobotic]

Yeah that forward hose is pretty cheap, I forgot about that. The rear hose is a bit more expensive, it's about $80.

[Kolbenringe]

Yeah that forward hose is pretty cheap, I forgot about that. The rear hose is a bit more expensive, it's about $80.

Completely nuts. We have in the high 40 range from Audi and about 27 for OEM. I gotta say I can't believe the prices paid in the US. It was never this much of a spread even into the early 2000s and I would never have one of these cars there. Getting parts here in person is already difficult enough, despite the cars coming from here. Everything has to be ordered and dealers are really not keeping stock on much, including for the B9. The entire industry is signalling shifts, but that's a different story.

[DrGER]

Yeah that forward hose is pretty cheap, I forgot about that. The rear hose is a bit more expensive, it's about $80.

Hmm, ETKA shows the rear hose p/n as 8K0121081CA (PR-GP2), current US VAG dealer list $42 (found for $27 at some VW on-line sources). --g

[audrobotic]

Hmm, ETKA shows the rear hose p/n as 8K0121081CA (PR-GP2), current US VAG dealer list $42 (found for $27 at some VW on-line sources). --g

Interesting - ECS tuning shows a "AH" suffix part.

https://www.ecstuning.com/b-genuine-...e/8k0121081ah/

[DrGER]

Interesting - ECS tuning shows a "AH" suffix part.

https://www.ecstuning.com/b-genuine-...e/8k0121081ah/

Yeah, could be, depending on PR codes (GP1 vs GP2) and build date: https://audi.7zap.com/en/rdw/audi+a4.../1/121-121030/ --g