Cleaning hard coolant line

[Wyd]

Removed my hard coolant lines from the back of my engine to find my temp sensor(?) o ring was mauled and dusted. leaving the inside of my coolant line to feel like dull sandpaper.

any remedies or strong cleaning agent ideas to dissolve it without scrubbing in there?

[2004B6S4]

why not scrub? I'd use a wire brush

[badger.]

if it is water scale maybe try a little vinegar and a good scrub with a nylon brush

[Invadher1]

Some gunk on a cloth or soft brush should remove awe that gunk


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[Wyd]

Would be a pita to scrub oil the entire line considering how narrow it is, and the bending in the line

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Not familiar with what water scale is but I'll go ahead and give it a try

[emilio]

those get very brittle, and there's a decent chance you'll break it when cleaning. i wouldn't worry about it, your whole coolant system is probably coated with that; mine was similar when i replaced some fittings.

- emilio

[emilio]

also, i see you have your engine out. if you have the budget, i would recommend replacing all coolant fittings and lines back there! they eventually break and they're a pain to get to; i had to replace the heater core connection and there was a lot of blindly reaching back there. that temperature sensor and the oil pressure switch are also easy to swap out, and if you're really going for broke replacing the power steering hoses is also good preventative maintenance (though not that inexpensive).

- emilio

[2004B6S4]

Would be a pita to scrub oil the entire line considering how narrow it is, and the bending in the line

oh now I see, I thought you were just talking about cleaning the area where the o-ring seals. That's all I would worry about, personally.

[badger.]

oh now I see, I thought you were just talking about cleaning the area where the o-ring seals. That's all I would worry about, personally.

same here. lol... no good way to clean the entire system that I know of.

[Wyd]

Thank for the input. Also I'm replacing all plastic fittings and seals back there. Doing my chains and finding problems along the way :/
Also Emilio had noted the actual hard coolant lines becoming my brittle? Is that likely seeming they're metal I had thought.

[badger.]

The crossover line on the back of the engine and a few other bits are metal. But Emilio was probably referring to the vast majority of the connectors/tees/Y's etc throughout the coolant system. Many of the hose fittings that go onto the metallic bits are actually plastic. With age+heat (something these S4s have in spades...) plastic can get brittle and break easier as things are shifted around. Similar to what he was saying, I broke one of them going to my heater core when I was reinstalling my engine, and another on the passenger bank near the airbox when I was doing a compression test.

I wouldn't worry about the actual metal ones. Just make sure you replace all the orings for them. The metal itself will not get brittle.

[emilio]

yes, i meant the plastic fittings and rubber (EPDM) hoses. i had a heater core line burst back there, and have also cracked the three-way fitting in the front, near the airbox and radiator. i would do them if i had the cash and the engine was over 100K miles.

granted, these hoses and fittings can be surprisingly expensive. i think you can replace most bare hose with off-the-shelf stuff, but any fittings are probably best purchased as OEM. there are also some hoses with separable fittings that only have a part number for the assembly, meaning the individual fitting may not be sold.

- emilio